xpath.c

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/*
 * xpath.c: XML Path Language implementation
 *          XPath is a language for addressing parts of an XML document,
 *          designed to be used by both XSLT and XPointer
 *
 * Reference: W3C Recommendation 16 November 1999
 *     http://www.w3.org/TR/1999/REC-xpath-19991116
 * Public reference:
 *     http://www.w3.org/TR/xpath
 *
 * See Copyright for the status of this software
 *
 * Author: daniel@veillard.com
 *
 */
 
/* To avoid EBCDIC trouble when parsing on zOS */
#if defined(__MVS__)
#pragma convert("ISO8859-1")
#endif
 
#define IN_LIBXML
#include "libxml.h"
 
#include <limits.h>
#include <string.h>
#include <stddef.h>
#include <math.h>
#include <float.h>
#include <ctype.h>
 
#include <libxml/xmlmemory.h>
#include <libxml/tree.h>
#include <libxml/xpath.h>
#include <libxml/xpathInternals.h>
#include <libxml/parserInternals.h>
#include <libxml/hash.h>
#ifdef LIBXML_XPTR_LOCS_ENABLED
#include <libxml/xpointer.h>
#endif
#ifdef LIBXML_DEBUG_ENABLED
#include <libxml/debugXML.h>
#endif
#include <libxml/xmlerror.h>
#include <libxml/threads.h>
#ifdef LIBXML_PATTERN_ENABLED
#include <libxml/pattern.h>
#endif
 
#include "private/buf.h"
#include "private/error.h"
#include "private/xpath.h"
 
#ifdef LIBXML_PATTERN_ENABLED
#define XPATH_STREAMING
#endif
 
#define TODO                                \
    xmlGenericError(xmlGenericErrorContext,             \
        "Unimplemented block at %s:%d\n",               \
            __FILE__, __LINE__);
 
#define WITH_TIM_SORT
 
/*
* XP_OPTIMIZED_NON_ELEM_COMPARISON:
* If defined, this will use xmlXPathCmpNodesExt() instead of
* xmlXPathCmpNodes(). The new function is optimized comparison of
* non-element nodes; actually it will speed up comparison only if
* xmlXPathOrderDocElems() was called in order to index the elements of
* a tree in document order; Libxslt does such an indexing, thus it will
* benefit from this optimization.
*/
#define XP_OPTIMIZED_NON_ELEM_COMPARISON
 
/*
* XP_OPTIMIZED_FILTER_FIRST:
* If defined, this will optimize expressions like "key('foo', 'val')[b][1]"
* in a way, that it stop evaluation at the first node.
*/
#define XP_OPTIMIZED_FILTER_FIRST
 
/*
 * XPATH_MAX_STEPS:
 * when compiling an XPath expression we arbitrary limit the maximum
 * number of step operation in the compiled expression. 1000000 is
 * an insanely large value which should never be reached under normal
 * circumstances
 */
#define XPATH_MAX_STEPS 1000000
 
/*
 * XPATH_MAX_STACK_DEPTH:
 * when evaluating an XPath expression we arbitrary limit the maximum
 * number of object allowed to be pushed on the stack. 1000000 is
 * an insanely large value which should never be reached under normal
 * circumstances
 */
#define XPATH_MAX_STACK_DEPTH 1000000
 
/*
 * XPATH_MAX_NODESET_LENGTH:
 * when evaluating an XPath expression nodesets are created and we
 * arbitrary limit the maximum length of those node set. 10000000 is
 * an insanely large value which should never be reached under normal
 * circumstances, one would first need to construct an in memory tree
 * with more than 10 millions nodes.
 */
#define XPATH_MAX_NODESET_LENGTH 10000000
 
/*
 * XPATH_MAX_RECRUSION_DEPTH:
 * Maximum amount of nested functions calls when parsing or evaluating
 * expressions
 */
#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
#define XPATH_MAX_RECURSION_DEPTH 500
#elif defined(_WIN32)
/* Windows typically limits stack size to 1MB. */
#define XPATH_MAX_RECURSION_DEPTH 1000
#else
#define XPATH_MAX_RECURSION_DEPTH 5000
#endif
 
/*
 * TODO:
 * There are a few spots where some tests are done which depend upon ascii
 * data.  These should be enhanced for full UTF8 support (see particularly
 * any use of the macros IS_ASCII_CHARACTER and IS_ASCII_DIGIT)
 */
 
#if defined(LIBXML_XPATH_ENABLED) || defined(LIBXML_SCHEMAS_ENABLED)
 
/************************************************************************
 *                                  *
 *          Floating point stuff                *
 *                                  *
 ************************************************************************/
 
double xmlXPathNAN = 0.0;
double xmlXPathPINF = 0.0;
double xmlXPathNINF = 0.0;
 
void
xmlXPathInit(void) {
    xmlInitParser();
}
 
ATTRIBUTE_NO_SANITIZE("float-divide-by-zero")
void
xmlInitXPathInternal(void) {
#if defined(NAN) && defined(INFINITY)
    xmlXPathNAN = NAN;
    xmlXPathPINF = INFINITY;
    xmlXPathNINF = -INFINITY;
#else
    /* MSVC doesn't allow division by zero in constant expressions. */
    double zero = 0.0;
    xmlXPathNAN = 0.0 / zero;
    xmlXPathPINF = 1.0 / zero;
    xmlXPathNINF = -xmlXPathPINF;
#endif
}
 
int
xmlXPathIsNaN(double val) {
#ifdef isnan
    return isnan(val);
#else
    return !(val == val);
#endif
}
 
int
xmlXPathIsInf(double val) {
#ifdef isinf
    return isinf(val) ? (val > 0 ? 1 : -1) : 0;
#else
    if (val >= xmlXPathPINF)
        return 1;
    if (val <= -xmlXPathPINF)
        return -1;
    return 0;
#endif
}
 
#endif /* SCHEMAS or XPATH */
 
#ifdef LIBXML_XPATH_ENABLED
 
/*
 * TODO: when compatibility allows remove all "fake node libxslt" strings
 *       the test should just be name[0] = ' '
 */
 
static xmlNs xmlXPathXMLNamespaceStruct = {
    NULL,
    XML_NAMESPACE_DECL,
    XML_XML_NAMESPACE,
    BAD_CAST "xml",
    NULL,
    NULL
};
static xmlNsPtr xmlXPathXMLNamespace = &xmlXPathXMLNamespaceStruct;
#ifndef LIBXML_THREAD_ENABLED
/*
 * Optimizer is disabled only when threaded apps are detected while
 * the library ain't compiled for thread safety.
 */
static int xmlXPathDisableOptimizer = 0;
#endif
 
static void
xmlXPathNodeSetClear(xmlNodeSetPtr set, int hasNsNodes);
 
#ifdef XP_OPTIMIZED_NON_ELEM_COMPARISON
static int
xmlXPathCmpNodesExt(xmlNodePtr node1, xmlNodePtr node2) {
    int depth1, depth2;
    int misc = 0, precedence1 = 0, precedence2 = 0;
    xmlNodePtr miscNode1 = NULL, miscNode2 = NULL;
    xmlNodePtr cur, root;
    ptrdiff_t l1, l2;
 
    if ((node1 == NULL) || (node2 == NULL))
    return(-2);
 
    if (node1 == node2)
    return(0);
 
    /*
     * a couple of optimizations which will avoid computations in most cases
     */
    switch (node1->type) {
    case XML_ELEMENT_NODE:
        if (node2->type == XML_ELEMENT_NODE) {
        if ((0 > (ptrdiff_t) node1->content) &&
            (0 > (ptrdiff_t) node2->content) &&
            (node1->doc == node2->doc))
        {
            l1 = -((ptrdiff_t) node1->content);
            l2 = -((ptrdiff_t) node2->content);
            if (l1 < l2)
            return(1);
            if (l1 > l2)
            return(-1);
        } else
            goto turtle_comparison;
        }
        break;
    case XML_ATTRIBUTE_NODE:
        precedence1 = 1; /* element is owner */
        miscNode1 = node1;
        node1 = node1->parent;
        misc = 1;
        break;
    case XML_TEXT_NODE:
    case XML_CDATA_SECTION_NODE:
    case XML_COMMENT_NODE:
    case XML_PI_NODE: {
        miscNode1 = node1;
        /*
        * Find nearest element node.
        */
        if (node1->prev != NULL) {
        do {
            node1 = node1->prev;
            if (node1->type == XML_ELEMENT_NODE) {
            precedence1 = 3; /* element in prev-sibl axis */
            break;
            }
            if (node1->prev == NULL) {
            precedence1 = 2; /* element is parent */
            /*
            * URGENT TODO: Are there any cases, where the
            * parent of such a node is not an element node?
            */
            node1 = node1->parent;
            break;
            }
        } while (1);
        } else {
        precedence1 = 2; /* element is parent */
        node1 = node1->parent;
        }
        if ((node1 == NULL) || (node1->type != XML_ELEMENT_NODE) ||
        (0 <= (ptrdiff_t) node1->content)) {
        /*
        * Fallback for whatever case.
        */
        node1 = miscNode1;
        precedence1 = 0;
        } else
        misc = 1;
    }
        break;
    case XML_NAMESPACE_DECL:
        /*
        * TODO: why do we return 1 for namespace nodes?
        */
        return(1);
    default:
        break;
    }
    switch (node2->type) {
    case XML_ELEMENT_NODE:
        break;
    case XML_ATTRIBUTE_NODE:
        precedence2 = 1; /* element is owner */
        miscNode2 = node2;
        node2 = node2->parent;
        misc = 1;
        break;
    case XML_TEXT_NODE:
    case XML_CDATA_SECTION_NODE:
    case XML_COMMENT_NODE:
    case XML_PI_NODE: {
        miscNode2 = node2;
        if (node2->prev != NULL) {
        do {
            node2 = node2->prev;
            if (node2->type == XML_ELEMENT_NODE) {
            precedence2 = 3; /* element in prev-sibl axis */
            break;
            }
            if (node2->prev == NULL) {
            precedence2 = 2; /* element is parent */
            node2 = node2->parent;
            break;
            }
        } while (1);
        } else {
        precedence2 = 2; /* element is parent */
        node2 = node2->parent;
        }
        if ((node2 == NULL) || (node2->type != XML_ELEMENT_NODE) ||
        (0 <= (ptrdiff_t) node2->content))
        {
        node2 = miscNode2;
        precedence2 = 0;
        } else
        misc = 1;
    }
        break;
    case XML_NAMESPACE_DECL:
        return(1);
    default:
        break;
    }
    if (misc) {
    if (node1 == node2) {
        if (precedence1 == precedence2) {
        /*
        * The ugly case; but normally there aren't many
        * adjacent non-element nodes around.
        */
        cur = miscNode2->prev;
        while (cur != NULL) {
            if (cur == miscNode1)
            return(1);
            if (cur->type == XML_ELEMENT_NODE)
            return(-1);
            cur = cur->prev;
        }
        return (-1);
        } else {
        /*
        * Evaluate based on higher precedence wrt to the element.
        * TODO: This assumes attributes are sorted before content.
        *   Is this 100% correct?
        */
        if (precedence1 < precedence2)
            return(1);
        else
            return(-1);
        }
    }
    /*
    * Special case: One of the helper-elements is contained by the other.
    * <foo>
    *   <node2>
    *     <node1>Text-1(precedence1 == 2)</node1>
    *   </node2>
    *   Text-6(precedence2 == 3)
    * </foo>
    */
    if ((precedence2 == 3) && (precedence1 > 1)) {
        cur = node1->parent;
        while (cur) {
        if (cur == node2)
            return(1);
        cur = cur->parent;
        }
    }
    if ((precedence1 == 3) && (precedence2 > 1)) {
        cur = node2->parent;
        while (cur) {
        if (cur == node1)
            return(-1);
        cur = cur->parent;
        }
    }
    }
 
    /*
     * Speedup using document order if available.
     */
    if ((node1->type == XML_ELEMENT_NODE) &&
    (node2->type == XML_ELEMENT_NODE) &&
    (0 > (ptrdiff_t) node1->content) &&
    (0 > (ptrdiff_t) node2->content) &&
    (node1->doc == node2->doc)) {
 
    l1 = -((ptrdiff_t) node1->content);
    l2 = -((ptrdiff_t) node2->content);
    if (l1 < l2)
        return(1);
    if (l1 > l2)
        return(-1);
    }
 
turtle_comparison:
 
    if (node1 == node2->prev)
    return(1);
    if (node1 == node2->next)
    return(-1);
    /*
     * compute depth to root
     */
    for (depth2 = 0, cur = node2; cur->parent != NULL; cur = cur->parent) {
    if (cur->parent == node1)
        return(1);
    depth2++;
    }
    root = cur;
    for (depth1 = 0, cur = node1; cur->parent != NULL; cur = cur->parent) {
    if (cur->parent == node2)
        return(-1);
    depth1++;
    }
    /*
     * Distinct document (or distinct entities :-( ) case.
     */
    if (root != cur) {
    return(-2);
    }
    /*
     * get the nearest common ancestor.
     */
    while (depth1 > depth2) {
    depth1--;
    node1 = node1->parent;
    }
    while (depth2 > depth1) {
    depth2--;
    node2 = node2->parent;
    }
    while (node1->parent != node2->parent) {
    node1 = node1->parent;
    node2 = node2->parent;
    /* should not happen but just in case ... */
    if ((node1 == NULL) || (node2 == NULL))
        return(-2);
    }
    /*
     * Find who's first.
     */
    if (node1 == node2->prev)
    return(1);
    if (node1 == node2->next)
    return(-1);
    /*
     * Speedup using document order if available.
     */
    if ((node1->type == XML_ELEMENT_NODE) &&
    (node2->type == XML_ELEMENT_NODE) &&
    (0 > (ptrdiff_t) node1->content) &&
    (0 > (ptrdiff_t) node2->content) &&
    (node1->doc == node2->doc)) {
 
    l1 = -((ptrdiff_t) node1->content);
    l2 = -((ptrdiff_t) node2->content);
    if (l1 < l2)
        return(1);
    if (l1 > l2)
        return(-1);
    }
 
    for (cur = node1->next;cur != NULL;cur = cur->next)
    if (cur == node2)
        return(1);
    return(-1); /* assume there is no sibling list corruption */
}
#endif /* XP_OPTIMIZED_NON_ELEM_COMPARISON */
 
/*
 * Wrapper for the Timsort algorithm from timsort.h
 */
#ifdef WITH_TIM_SORT
#define SORT_NAME libxml_domnode
#define SORT_TYPE xmlNodePtr
static
int wrap_cmp( xmlNodePtr x, xmlNodePtr y );
#ifdef XP_OPTIMIZED_NON_ELEM_COMPARISON
    static int wrap_cmp( xmlNodePtr x, xmlNodePtr y )
    {
        int res = xmlXPathCmpNodesExt(x, y);
        return res == -2 ? res : -res;
    }
#else
    static int wrap_cmp( xmlNodePtr x, xmlNodePtr y )
    {
        int res = xmlXPathCmpNodes(x, y);
        return res == -2 ? res : -res;
    }
#endif
#define SORT_CMP(x, y)  (wrap_cmp(x, y))
#include "timsort.h"
#endif /* WITH_TIM_SORT */
 
/************************************************************************
 *                                  *
 *          Error handling routines             *
 *                                  *
 ************************************************************************/
 
#define XP_ERRORNULL(X)                         \
    { xmlXPathErr(ctxt, X); return(NULL); }
 
/*
 * The array xmlXPathErrorMessages corresponds to the enum xmlXPathError
 */
static const char* const xmlXPathErrorMessages[] = {
    "Ok\n",
    "Number encoding\n",
    "Unfinished literal\n",
    "Start of literal\n",
    "Expected $ for variable reference\n",
    "Undefined variable\n",
    "Invalid predicate\n",
    "Invalid expression\n",
    "Missing closing curly brace\n",
    "Unregistered function\n",
    "Invalid operand\n",
    "Invalid type\n",
    "Invalid number of arguments\n",
    "Invalid context size\n",
    "Invalid context position\n",
    "Memory allocation error\n",
    "Syntax error\n",
    "Resource error\n",
    "Sub resource error\n",
    "Undefined namespace prefix\n",
    "Encoding error\n",
    "Char out of XML range\n",
    "Invalid or incomplete context\n",
    "Stack usage error\n",
    "Forbidden variable\n",
    "Operation limit exceeded\n",
    "Recursion limit exceeded\n",
    "?? Unknown error ??\n" /* Must be last in the list! */
};
#define MAXERRNO ((int)(sizeof(xmlXPathErrorMessages) / \
           sizeof(xmlXPathErrorMessages[0])) - 1)
static void
xmlXPathErrMemory(xmlXPathContextPtr ctxt, const char *extra)
{
    if (ctxt != NULL) {
        xmlResetError(&ctxt->lastError);
        if (extra) {
            xmlChar buf[200];
 
            xmlStrPrintf(buf, 200,
                         "Memory allocation failed : %s\n",
                         extra);
            ctxt->lastError.message = (char *) xmlStrdup(buf);
        } else {
            ctxt->lastError.message = (char *)
           xmlStrdup(BAD_CAST "Memory allocation failed\n");
        }
        ctxt->lastError.domain = XML_FROM_XPATH;
        ctxt->lastError.code = XML_ERR_NO_MEMORY;
    if (ctxt->error != NULL)
        ctxt->error(ctxt->userData, &ctxt->lastError);
    } else {
        if (extra)
            __xmlRaiseError(NULL, NULL, NULL,
                            NULL, NULL, XML_FROM_XPATH,
                            XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0,
                            extra, NULL, NULL, 0, 0,
                            "Memory allocation failed : %s\n", extra);
        else
            __xmlRaiseError(NULL, NULL, NULL,
                            NULL, NULL, XML_FROM_XPATH,
                            XML_ERR_NO_MEMORY, XML_ERR_FATAL, NULL, 0,
                            NULL, NULL, NULL, 0, 0,
                            "Memory allocation failed\n");
    }
}
 
static void
xmlXPathPErrMemory(xmlXPathParserContextPtr ctxt, const char *extra)
{
    if (ctxt == NULL)
    xmlXPathErrMemory(NULL, extra);
    else {
    ctxt->error = XPATH_MEMORY_ERROR;
    xmlXPathErrMemory(ctxt->context, extra);
    }
}
 
void
xmlXPathErr(xmlXPathParserContextPtr ctxt, int error)
{
    if ((error < 0) || (error > MAXERRNO))
    error = MAXERRNO;
    if (ctxt == NULL) {
    __xmlRaiseError(NULL, NULL, NULL,
            NULL, NULL, XML_FROM_XPATH,
            error + XML_XPATH_EXPRESSION_OK - XPATH_EXPRESSION_OK,
            XML_ERR_ERROR, NULL, 0,
            NULL, NULL, NULL, 0, 0,
            "%s", xmlXPathErrorMessages[error]);
    return;
    }
    /* Only report the first error */
    if (ctxt->error != 0)
        return;
    ctxt->error = error;
    if (ctxt->context == NULL) {
    __xmlRaiseError(NULL, NULL, NULL,
            NULL, NULL, XML_FROM_XPATH,
            error + XML_XPATH_EXPRESSION_OK - XPATH_EXPRESSION_OK,
            XML_ERR_ERROR, NULL, 0,
            (const char *) ctxt->base, NULL, NULL,
            ctxt->cur - ctxt->base, 0,
            "%s", xmlXPathErrorMessages[error]);
    return;
    }
 
    /* cleanup current last error */
    xmlResetError(&ctxt->context->lastError);
 
    ctxt->context->lastError.domain = XML_FROM_XPATH;
    ctxt->context->lastError.code = error + XML_XPATH_EXPRESSION_OK -
                           XPATH_EXPRESSION_OK;
    ctxt->context->lastError.level = XML_ERR_ERROR;
    ctxt->context->lastError.str1 = (char *) xmlStrdup(ctxt->base);
    ctxt->context->lastError.int1 = ctxt->cur - ctxt->base;
    ctxt->context->lastError.node = ctxt->context->debugNode;
    if (ctxt->context->error != NULL) {
    ctxt->context->error(ctxt->context->userData,
                         &ctxt->context->lastError);
    } else {
    __xmlRaiseError(NULL, NULL, NULL,
            NULL, ctxt->context->debugNode, XML_FROM_XPATH,
            error + XML_XPATH_EXPRESSION_OK - XPATH_EXPRESSION_OK,
            XML_ERR_ERROR, NULL, 0,
            (const char *) ctxt->base, NULL, NULL,
            ctxt->cur - ctxt->base, 0,
            "%s", xmlXPathErrorMessages[error]);
    }
 
}
 
void
xmlXPatherror(xmlXPathParserContextPtr ctxt, const char *file ATTRIBUTE_UNUSED,
              int line ATTRIBUTE_UNUSED, int no) {
    xmlXPathErr(ctxt, no);
}
 
static int
xmlXPathCheckOpLimit(xmlXPathParserContextPtr ctxt, unsigned long opCount) {
    xmlXPathContextPtr xpctxt = ctxt->context;
 
    if ((opCount > xpctxt->opLimit) ||
        (xpctxt->opCount > xpctxt->opLimit - opCount)) {
        xpctxt->opCount = xpctxt->opLimit;
        xmlXPathErr(ctxt, XPATH_OP_LIMIT_EXCEEDED);
        return(-1);
    }
 
    xpctxt->opCount += opCount;
    return(0);
}
 
#define OP_LIMIT_EXCEEDED(ctxt, n) \
    ((ctxt->context->opLimit != 0) && (xmlXPathCheckOpLimit(ctxt, n) < 0))
 
/************************************************************************
 *                                  *
 *          Utilities                   *
 *                                  *
 ************************************************************************/
 
typedef struct _xmlPointerList xmlPointerList;
typedef xmlPointerList *xmlPointerListPtr;
struct _xmlPointerList {
    void **items;
    int number;
    int size;
};
/*
* TODO: Since such a list-handling is used in xmlschemas.c and libxslt
* and here, we should make the functions public.
*/
static int
xmlPointerListAddSize(xmlPointerListPtr list,
               void *item,
               int initialSize)
{
    if (list->size <= list->number) {
        void **tmp;
        size_t newSize;
 
        if (list->size == 0) {
            if (initialSize <= 0)
                initialSize = 1;
            newSize = initialSize;
        } else {
            if (list->size > 50000000) {
                xmlXPathErrMemory(NULL,
                    "xmlPointerListAddSize: re-allocating item\n");
                return(-1);
            }
        newSize = list->size * 2;
        }
    tmp = (void **) xmlRealloc(list->items, newSize * sizeof(void *));
    if (tmp == NULL) {
        xmlXPathErrMemory(NULL,
        "xmlPointerListAddSize: re-allocating item\n");
        return(-1);
    }
        list->items = tmp;
        list->size = newSize;
    }
    list->items[list->number++] = item;
    return(0);
}
 
static xmlPointerListPtr
xmlPointerListCreate(int initialSize)
{
    xmlPointerListPtr ret;
 
    ret = xmlMalloc(sizeof(xmlPointerList));
    if (ret == NULL) {
    xmlXPathErrMemory(NULL,
        "xmlPointerListCreate: allocating item\n");
    return (NULL);
    }
    memset(ret, 0, sizeof(xmlPointerList));
    if (initialSize > 0) {
    xmlPointerListAddSize(ret, NULL, initialSize);
    ret->number = 0;
    }
    return (ret);
}
 
static void
xmlPointerListFree(xmlPointerListPtr list)
{
    if (list == NULL)
    return;
    if (list->items != NULL)
    xmlFree(list->items);
    xmlFree(list);
}
 
/************************************************************************
 *                                  *
 *          Parser Types                    *
 *                                  *
 ************************************************************************/
 
/*
 * Types are private:
 */
 
typedef enum {
    XPATH_OP_END=0,
    XPATH_OP_AND,
    XPATH_OP_OR,
    XPATH_OP_EQUAL,
    XPATH_OP_CMP,
    XPATH_OP_PLUS,
    XPATH_OP_MULT,
    XPATH_OP_UNION,
    XPATH_OP_ROOT,
    XPATH_OP_NODE,
    XPATH_OP_COLLECT,
    XPATH_OP_VALUE, /* 11 */
    XPATH_OP_VARIABLE,
    XPATH_OP_FUNCTION,
    XPATH_OP_ARG,
    XPATH_OP_PREDICATE,
    XPATH_OP_FILTER, /* 16 */
    XPATH_OP_SORT /* 17 */
#ifdef LIBXML_XPTR_LOCS_ENABLED
    ,XPATH_OP_RANGETO
#endif
} xmlXPathOp;
 
typedef enum {
    AXIS_ANCESTOR = 1,
    AXIS_ANCESTOR_OR_SELF,
    AXIS_ATTRIBUTE,
    AXIS_CHILD,
    AXIS_DESCENDANT,
    AXIS_DESCENDANT_OR_SELF,
    AXIS_FOLLOWING,
    AXIS_FOLLOWING_SIBLING,
    AXIS_NAMESPACE,
    AXIS_PARENT,
    AXIS_PRECEDING,
    AXIS_PRECEDING_SIBLING,
    AXIS_SELF
} xmlXPathAxisVal;
 
typedef enum {
    NODE_TEST_NONE = 0,
    NODE_TEST_TYPE = 1,
    NODE_TEST_PI = 2,
    NODE_TEST_ALL = 3,
    NODE_TEST_NS = 4,
    NODE_TEST_NAME = 5
} xmlXPathTestVal;
 
typedef enum {
    NODE_TYPE_NODE = 0,
    NODE_TYPE_COMMENT = XML_COMMENT_NODE,
    NODE_TYPE_TEXT = XML_TEXT_NODE,
    NODE_TYPE_PI = XML_PI_NODE
} xmlXPathTypeVal;
 
typedef struct _xmlXPathStepOp xmlXPathStepOp;
typedef xmlXPathStepOp *xmlXPathStepOpPtr;
struct _xmlXPathStepOp {
    xmlXPathOp op;      /* The identifier of the operation */
    int ch1;            /* First child */
    int ch2;            /* Second child */
    int value;
    int value2;
    int value3;
    void *value4;
    void *value5;
    xmlXPathFunction cache;
    void *cacheURI;
};
 
struct _xmlXPathCompExpr {
    int nbStep;         /* Number of steps in this expression */
    int maxStep;        /* Maximum number of steps allocated */
    xmlXPathStepOp *steps;  /* ops for computation of this expression */
    int last;           /* index of last step in expression */
    xmlChar *expr;      /* the expression being computed */
    xmlDictPtr dict;        /* the dictionary to use if any */
#ifdef XPATH_STREAMING
    xmlPatternPtr stream;
#endif
};
 
/************************************************************************
 *                                  *
 *          Forward declarations                *
 *                                  *
 ************************************************************************/
static void
xmlXPathFreeValueTree(xmlNodeSetPtr obj);
static void
xmlXPathReleaseObject(xmlXPathContextPtr ctxt, xmlXPathObjectPtr obj);
static int
xmlXPathCompOpEvalFirst(xmlXPathParserContextPtr ctxt,
                        xmlXPathStepOpPtr op, xmlNodePtr *first);
static int
xmlXPathCompOpEvalToBoolean(xmlXPathParserContextPtr ctxt,
                xmlXPathStepOpPtr op,
                int isPredicate);
static void
xmlXPathFreeObjectEntry(void *obj, const xmlChar *name);
 
/************************************************************************
 *                                  *
 *          Parser Type functions               *
 *                                  *
 ************************************************************************/
 
static xmlXPathCompExprPtr
xmlXPathNewCompExpr(void) {
    xmlXPathCompExprPtr cur;
 
    cur = (xmlXPathCompExprPtr) xmlMalloc(sizeof(xmlXPathCompExpr));
    if (cur == NULL) {
        xmlXPathErrMemory(NULL, "allocating component\n");
    return(NULL);
    }
    memset(cur, 0, sizeof(xmlXPathCompExpr));
    cur->maxStep = 10;
    cur->nbStep = 0;
    cur->steps = (xmlXPathStepOp *) xmlMalloc(cur->maxStep *
                                       sizeof(xmlXPathStepOp));
    if (cur->steps == NULL) {
        xmlXPathErrMemory(NULL, "allocating steps\n");
    xmlFree(cur);
    return(NULL);
    }
    memset(cur->steps, 0, cur->maxStep * sizeof(xmlXPathStepOp));
    cur->last = -1;
    return(cur);
}
 
void
xmlXPathFreeCompExpr(xmlXPathCompExprPtr comp)
{
    xmlXPathStepOpPtr op;
    int i;
 
    if (comp == NULL)
        return;
    if (comp->dict == NULL) {
    for (i = 0; i < comp->nbStep; i++) {
        op = &comp->steps[i];
        if (op->value4 != NULL) {
        if (op->op == XPATH_OP_VALUE)
            xmlXPathFreeObject(op->value4);
        else
            xmlFree(op->value4);
        }
        if (op->value5 != NULL)
        xmlFree(op->value5);
    }
    } else {
    for (i = 0; i < comp->nbStep; i++) {
        op = &comp->steps[i];
        if (op->value4 != NULL) {
        if (op->op == XPATH_OP_VALUE)
            xmlXPathFreeObject(op->value4);
        }
    }
        xmlDictFree(comp->dict);
    }
    if (comp->steps != NULL) {
        xmlFree(comp->steps);
    }
#ifdef XPATH_STREAMING
    if (comp->stream != NULL) {
        xmlFreePatternList(comp->stream);
    }
#endif
    if (comp->expr != NULL) {
        xmlFree(comp->expr);
    }
 
    xmlFree(comp);
}
 
static int
xmlXPathCompExprAdd(xmlXPathParserContextPtr ctxt, int ch1, int ch2,
   xmlXPathOp op, int value,
   int value2, int value3, void *value4, void *value5) {
    xmlXPathCompExprPtr comp = ctxt->comp;
    if (comp->nbStep >= comp->maxStep) {
    xmlXPathStepOp *real;
 
        if (comp->maxStep >= XPATH_MAX_STEPS) {
        xmlXPathPErrMemory(ctxt, "adding step\n");
        return(-1);
        }
    comp->maxStep *= 2;
    real = (xmlXPathStepOp *) xmlRealloc(comp->steps,
                              comp->maxStep * sizeof(xmlXPathStepOp));
    if (real == NULL) {
        comp->maxStep /= 2;
        xmlXPathPErrMemory(ctxt, "adding step\n");
        return(-1);
    }
    comp->steps = real;
    }
    comp->last = comp->nbStep;
    comp->steps[comp->nbStep].ch1 = ch1;
    comp->steps[comp->nbStep].ch2 = ch2;
    comp->steps[comp->nbStep].op = op;
    comp->steps[comp->nbStep].value = value;
    comp->steps[comp->nbStep].value2 = value2;
    comp->steps[comp->nbStep].value3 = value3;
    if ((comp->dict != NULL) &&
        ((op == XPATH_OP_FUNCTION) || (op == XPATH_OP_VARIABLE) ||
     (op == XPATH_OP_COLLECT))) {
        if (value4 != NULL) {
        comp->steps[comp->nbStep].value4 = (xmlChar *)
            (void *)xmlDictLookup(comp->dict, value4, -1);
        xmlFree(value4);
    } else
        comp->steps[comp->nbStep].value4 = NULL;
        if (value5 != NULL) {
        comp->steps[comp->nbStep].value5 = (xmlChar *)
            (void *)xmlDictLookup(comp->dict, value5, -1);
        xmlFree(value5);
    } else
        comp->steps[comp->nbStep].value5 = NULL;
    } else {
    comp->steps[comp->nbStep].value4 = value4;
    comp->steps[comp->nbStep].value5 = value5;
    }
    comp->steps[comp->nbStep].cache = NULL;
    return(comp->nbStep++);
}
 
static void
xmlXPathCompSwap(xmlXPathStepOpPtr op) {
    int tmp;
 
#ifndef LIBXML_THREAD_ENABLED
    /*
     * Since this manipulates possibly shared variables, this is
     * disabled if one detects that the library is used in a multithreaded
     * application
     */
    if (xmlXPathDisableOptimizer)
    return;
#endif
 
    tmp = op->ch1;
    op->ch1 = op->ch2;
    op->ch2 = tmp;
}
 
#define PUSH_FULL_EXPR(op, op1, op2, val, val2, val3, val4, val5)   \
    xmlXPathCompExprAdd(ctxt, (op1), (op2),         \
                    (op), (val), (val2), (val3), (val4), (val5))
#define PUSH_LONG_EXPR(op, val, val2, val3, val4, val5)         \
    xmlXPathCompExprAdd(ctxt, ctxt->comp->last, -1,     \
                    (op), (val), (val2), (val3), (val4), (val5))
 
#define PUSH_LEAVE_EXPR(op, val, val2)                  \
xmlXPathCompExprAdd(ctxt, -1, -1, (op), (val), (val2), 0 ,NULL ,NULL)
 
#define PUSH_UNARY_EXPR(op, ch, val, val2)              \
xmlXPathCompExprAdd(ctxt, (ch), -1, (op), (val), (val2), 0 ,NULL ,NULL)
 
#define PUSH_BINARY_EXPR(op, ch1, ch2, val, val2)           \
xmlXPathCompExprAdd(ctxt, (ch1), (ch2), (op),           \
            (val), (val2), 0 ,NULL ,NULL)
 
/************************************************************************
 *                                  *
 *      XPath object cache structures               *
 *                                  *
 ************************************************************************/
 
/* #define XP_DEFAULT_CACHE_ON */
 
#define XP_HAS_CACHE(c) ((c != NULL) && ((c)->cache != NULL))
 
typedef struct _xmlXPathContextCache xmlXPathContextCache;
typedef xmlXPathContextCache *xmlXPathContextCachePtr;
struct _xmlXPathContextCache {
    xmlPointerListPtr nodesetObjs;  /* contains xmlXPathObjectPtr */
    xmlPointerListPtr stringObjs;   /* contains xmlXPathObjectPtr */
    xmlPointerListPtr booleanObjs;  /* contains xmlXPathObjectPtr */
    xmlPointerListPtr numberObjs;   /* contains xmlXPathObjectPtr */
    xmlPointerListPtr miscObjs;     /* contains xmlXPathObjectPtr */
    int maxNodeset;
    int maxString;
    int maxBoolean;
    int maxNumber;
    int maxMisc;
};
 
/************************************************************************
 *                                  *
 *      Debugging related functions             *
 *                                  *
 ************************************************************************/
 
#define STRANGE                         \
    xmlGenericError(xmlGenericErrorContext,             \
        "Internal error at %s:%d\n",                \
            __FILE__, __LINE__);
 
#ifdef LIBXML_DEBUG_ENABLED
static void
xmlXPathDebugDumpNode(FILE *output, xmlNodePtr cur, int depth) {
    int i;
    char shift[100];
 
    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
    if (cur == NULL) {
    fprintf(output, "%s", shift);
    fprintf(output, "Node is NULL !\n");
    return;
 
    }
 
    if ((cur->type == XML_DOCUMENT_NODE) ||
         (cur->type == XML_HTML_DOCUMENT_NODE)) {
    fprintf(output, "%s", shift);
    fprintf(output, " /\n");
    } else if (cur->type == XML_ATTRIBUTE_NODE)
    xmlDebugDumpAttr(output, (xmlAttrPtr)cur, depth);
    else
    xmlDebugDumpOneNode(output, cur, depth);
}
static void
xmlXPathDebugDumpNodeList(FILE *output, xmlNodePtr cur, int depth) {
    xmlNodePtr tmp;
    int i;
    char shift[100];
 
    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
    if (cur == NULL) {
    fprintf(output, "%s", shift);
    fprintf(output, "Node is NULL !\n");
    return;
 
    }
 
    while (cur != NULL) {
    tmp = cur;
    cur = cur->next;
    xmlDebugDumpOneNode(output, tmp, depth);
    }
}
 
static void
xmlXPathDebugDumpNodeSet(FILE *output, xmlNodeSetPtr cur, int depth) {
    int i;
    char shift[100];
 
    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
 
    if (cur == NULL) {
    fprintf(output, "%s", shift);
    fprintf(output, "NodeSet is NULL !\n");
    return;
 
    }
 
    if (cur != NULL) {
    fprintf(output, "Set contains %d nodes:\n", cur->nodeNr);
    for (i = 0;i < cur->nodeNr;i++) {
        fprintf(output, "%s", shift);
        fprintf(output, "%d", i + 1);
        xmlXPathDebugDumpNode(output, cur->nodeTab[i], depth + 1);
    }
    }
}
 
static void
xmlXPathDebugDumpValueTree(FILE *output, xmlNodeSetPtr cur, int depth) {
    int i;
    char shift[100];
 
    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
 
    if ((cur == NULL) || (cur->nodeNr == 0) || (cur->nodeTab[0] == NULL)) {
    fprintf(output, "%s", shift);
    fprintf(output, "Value Tree is NULL !\n");
    return;
 
    }
 
    fprintf(output, "%s", shift);
    fprintf(output, "%d", i + 1);
    xmlXPathDebugDumpNodeList(output, cur->nodeTab[0]->children, depth + 1);
}
#if defined(LIBXML_XPTR_LOCS_ENABLED)
static void
xmlXPathDebugDumpLocationSet(FILE *output, xmlLocationSetPtr cur, int depth) {
    int i;
    char shift[100];
 
    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
 
    if (cur == NULL) {
    fprintf(output, "%s", shift);
    fprintf(output, "LocationSet is NULL !\n");
    return;
 
    }
 
    for (i = 0;i < cur->locNr;i++) {
    fprintf(output, "%s", shift);
        fprintf(output, "%d : ", i + 1);
    xmlXPathDebugDumpObject(output, cur->locTab[i], depth + 1);
    }
}
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
void
xmlXPathDebugDumpObject(FILE *output, xmlXPathObjectPtr cur, int depth) {
    int i;
    char shift[100];
 
    if (output == NULL) return;
 
    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
 
 
    fprintf(output, "%s", shift);
 
    if (cur == NULL) {
        fprintf(output, "Object is empty (NULL)\n");
    return;
    }
    switch(cur->type) {
        case XPATH_UNDEFINED:
        fprintf(output, "Object is uninitialized\n");
        break;
        case XPATH_NODESET:
        fprintf(output, "Object is a Node Set :\n");
        xmlXPathDebugDumpNodeSet(output, cur->nodesetval, depth);
        break;
    case XPATH_XSLT_TREE:
        fprintf(output, "Object is an XSLT value tree :\n");
        xmlXPathDebugDumpValueTree(output, cur->nodesetval, depth);
        break;
        case XPATH_BOOLEAN:
        fprintf(output, "Object is a Boolean : ");
        if (cur->boolval) fprintf(output, "true\n");
        else fprintf(output, "false\n");
        break;
        case XPATH_NUMBER:
        switch (xmlXPathIsInf(cur->floatval)) {
        case 1:
        fprintf(output, "Object is a number : Infinity\n");
        break;
        case -1:
        fprintf(output, "Object is a number : -Infinity\n");
        break;
        default:
        if (xmlXPathIsNaN(cur->floatval)) {
            fprintf(output, "Object is a number : NaN\n");
        } else if (cur->floatval == 0) {
                    /* Omit sign for negative zero. */
            fprintf(output, "Object is a number : 0\n");
        } else {
            fprintf(output, "Object is a number : %0g\n", cur->floatval);
        }
        }
        break;
        case XPATH_STRING:
        fprintf(output, "Object is a string : ");
        xmlDebugDumpString(output, cur->stringval);
        fprintf(output, "\n");
        break;
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_POINT:
        fprintf(output, "Object is a point : index %d in node", cur->index);
        xmlXPathDebugDumpNode(output, (xmlNodePtr) cur->user, depth + 1);
        fprintf(output, "\n");
        break;
    case XPATH_RANGE:
        if ((cur->user2 == NULL) ||
        ((cur->user2 == cur->user) && (cur->index == cur->index2))) {
        fprintf(output, "Object is a collapsed range :\n");
        fprintf(output, "%s", shift);
        if (cur->index >= 0)
            fprintf(output, "index %d in ", cur->index);
        fprintf(output, "node\n");
        xmlXPathDebugDumpNode(output, (xmlNodePtr) cur->user,
                          depth + 1);
        } else  {
        fprintf(output, "Object is a range :\n");
        fprintf(output, "%s", shift);
        fprintf(output, "From ");
        if (cur->index >= 0)
            fprintf(output, "index %d in ", cur->index);
        fprintf(output, "node\n");
        xmlXPathDebugDumpNode(output, (xmlNodePtr) cur->user,
                          depth + 1);
        fprintf(output, "%s", shift);
        fprintf(output, "To ");
        if (cur->index2 >= 0)
            fprintf(output, "index %d in ", cur->index2);
        fprintf(output, "node\n");
        xmlXPathDebugDumpNode(output, (xmlNodePtr) cur->user2,
                          depth + 1);
        fprintf(output, "\n");
        }
        break;
    case XPATH_LOCATIONSET:
        fprintf(output, "Object is a Location Set:\n");
        xmlXPathDebugDumpLocationSet(output,
            (xmlLocationSetPtr) cur->user, depth);
        break;
#endif /* LIBXML_XPTR_LOCS_ENABLED */
    case XPATH_USERS:
        fprintf(output, "Object is user defined\n");
        break;
    }
}
 
static void
xmlXPathDebugDumpStepOp(FILE *output, xmlXPathCompExprPtr comp,
                         xmlXPathStepOpPtr op, int depth) {
    int i;
    char shift[100];
 
    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
 
    fprintf(output, "%s", shift);
    if (op == NULL) {
    fprintf(output, "Step is NULL\n");
    return;
    }
    switch (op->op) {
        case XPATH_OP_END:
        fprintf(output, "END"); break;
        case XPATH_OP_AND:
        fprintf(output, "AND"); break;
        case XPATH_OP_OR:
        fprintf(output, "OR"); break;
        case XPATH_OP_EQUAL:
         if (op->value)
         fprintf(output, "EQUAL =");
         else
         fprintf(output, "EQUAL !=");
         break;
        case XPATH_OP_CMP:
         if (op->value)
         fprintf(output, "CMP <");
         else
         fprintf(output, "CMP >");
         if (!op->value2)
         fprintf(output, "=");
         break;
        case XPATH_OP_PLUS:
         if (op->value == 0)
         fprintf(output, "PLUS -");
         else if (op->value == 1)
         fprintf(output, "PLUS +");
         else if (op->value == 2)
         fprintf(output, "PLUS unary -");
         else if (op->value == 3)
         fprintf(output, "PLUS unary - -");
         break;
        case XPATH_OP_MULT:
         if (op->value == 0)
         fprintf(output, "MULT *");
         else if (op->value == 1)
         fprintf(output, "MULT div");
         else
         fprintf(output, "MULT mod");
         break;
        case XPATH_OP_UNION:
         fprintf(output, "UNION"); break;
        case XPATH_OP_ROOT:
         fprintf(output, "ROOT"); break;
        case XPATH_OP_NODE:
         fprintf(output, "NODE"); break;
        case XPATH_OP_SORT:
         fprintf(output, "SORT"); break;
        case XPATH_OP_COLLECT: {
        xmlXPathAxisVal axis = (xmlXPathAxisVal)op->value;
        xmlXPathTestVal test = (xmlXPathTestVal)op->value2;
        xmlXPathTypeVal type = (xmlXPathTypeVal)op->value3;
        const xmlChar *prefix = op->value4;
        const xmlChar *name = op->value5;
 
        fprintf(output, "COLLECT ");
        switch (axis) {
        case AXIS_ANCESTOR:
            fprintf(output, " 'ancestors' "); break;
        case AXIS_ANCESTOR_OR_SELF:
            fprintf(output, " 'ancestors-or-self' "); break;
        case AXIS_ATTRIBUTE:
            fprintf(output, " 'attributes' "); break;
        case AXIS_CHILD:
            fprintf(output, " 'child' "); break;
        case AXIS_DESCENDANT:
            fprintf(output, " 'descendant' "); break;
        case AXIS_DESCENDANT_OR_SELF:
            fprintf(output, " 'descendant-or-self' "); break;
        case AXIS_FOLLOWING:
            fprintf(output, " 'following' "); break;
        case AXIS_FOLLOWING_SIBLING:
            fprintf(output, " 'following-siblings' "); break;
        case AXIS_NAMESPACE:
            fprintf(output, " 'namespace' "); break;
        case AXIS_PARENT:
            fprintf(output, " 'parent' "); break;
        case AXIS_PRECEDING:
            fprintf(output, " 'preceding' "); break;
        case AXIS_PRECEDING_SIBLING:
            fprintf(output, " 'preceding-sibling' "); break;
        case AXIS_SELF:
            fprintf(output, " 'self' "); break;
        }
        switch (test) {
                case NODE_TEST_NONE:
            fprintf(output, "'none' "); break;
                case NODE_TEST_TYPE:
            fprintf(output, "'type' "); break;
                case NODE_TEST_PI:
            fprintf(output, "'PI' "); break;
                case NODE_TEST_ALL:
            fprintf(output, "'all' "); break;
                case NODE_TEST_NS:
            fprintf(output, "'namespace' "); break;
                case NODE_TEST_NAME:
            fprintf(output, "'name' "); break;
        }
        switch (type) {
                case NODE_TYPE_NODE:
            fprintf(output, "'node' "); break;
                case NODE_TYPE_COMMENT:
            fprintf(output, "'comment' "); break;
                case NODE_TYPE_TEXT:
            fprintf(output, "'text' "); break;
                case NODE_TYPE_PI:
            fprintf(output, "'PI' "); break;
        }
        if (prefix != NULL)
        fprintf(output, "%s:", prefix);
        if (name != NULL)
        fprintf(output, "%s", (const char *) name);
        break;
 
        }
    case XPATH_OP_VALUE: {
        xmlXPathObjectPtr object = (xmlXPathObjectPtr) op->value4;
 
        fprintf(output, "ELEM ");
        xmlXPathDebugDumpObject(output, object, 0);
        goto finish;
    }
    case XPATH_OP_VARIABLE: {
        const xmlChar *prefix = op->value5;
        const xmlChar *name = op->value4;
 
        if (prefix != NULL)
        fprintf(output, "VARIABLE %s:%s", prefix, name);
        else
        fprintf(output, "VARIABLE %s", name);
        break;
    }
    case XPATH_OP_FUNCTION: {
        int nbargs = op->value;
        const xmlChar *prefix = op->value5;
        const xmlChar *name = op->value4;
 
        if (prefix != NULL)
        fprintf(output, "FUNCTION %s:%s(%d args)",
            prefix, name, nbargs);
        else
        fprintf(output, "FUNCTION %s(%d args)", name, nbargs);
        break;
    }
        case XPATH_OP_ARG: fprintf(output, "ARG"); break;
        case XPATH_OP_PREDICATE: fprintf(output, "PREDICATE"); break;
        case XPATH_OP_FILTER: fprintf(output, "FILTER"); break;
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_OP_RANGETO: fprintf(output, "RANGETO"); break;
#endif
    default:
        fprintf(output, "UNKNOWN %d\n", op->op); return;
    }
    fprintf(output, "\n");
finish:
    if (op->ch1 >= 0)
    xmlXPathDebugDumpStepOp(output, comp, &comp->steps[op->ch1], depth + 1);
    if (op->ch2 >= 0)
    xmlXPathDebugDumpStepOp(output, comp, &comp->steps[op->ch2], depth + 1);
}
 
void
xmlXPathDebugDumpCompExpr(FILE *output, xmlXPathCompExprPtr comp,
                      int depth) {
    int i;
    char shift[100];
 
    if ((output == NULL) || (comp == NULL)) return;
 
    for (i = 0;((i < depth) && (i < 25));i++)
        shift[2 * i] = shift[2 * i + 1] = ' ';
    shift[2 * i] = shift[2 * i + 1] = 0;
 
    fprintf(output, "%s", shift);
 
#ifdef XPATH_STREAMING
    if (comp->stream) {
        fprintf(output, "Streaming Expression\n");
    } else
#endif
    {
        fprintf(output, "Compiled Expression : %d elements\n",
                comp->nbStep);
        i = comp->last;
        xmlXPathDebugDumpStepOp(output, comp, &comp->steps[i], depth + 1);
    }
}
 
#endif /* LIBXML_DEBUG_ENABLED */
 
/************************************************************************
 *                                  *
 *          XPath object caching                *
 *                                  *
 ************************************************************************/
 
static xmlXPathContextCachePtr
xmlXPathNewCache(void)
{
    xmlXPathContextCachePtr ret;
 
    ret = (xmlXPathContextCachePtr) xmlMalloc(sizeof(xmlXPathContextCache));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating object cache\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathContextCache));
    ret->maxNodeset = 100;
    ret->maxString = 100;
    ret->maxBoolean = 100;
    ret->maxNumber = 100;
    ret->maxMisc = 100;
    return(ret);
}
 
static void
xmlXPathCacheFreeObjectList(xmlPointerListPtr list)
{
    int i;
    xmlXPathObjectPtr obj;
 
    if (list == NULL)
    return;
 
    for (i = 0; i < list->number; i++) {
    obj = list->items[i];
    /*
    * Note that it is already assured that we don't need to
    * look out for namespace nodes in the node-set.
    */
    if (obj->nodesetval != NULL) {
        if (obj->nodesetval->nodeTab != NULL)
        xmlFree(obj->nodesetval->nodeTab);
        xmlFree(obj->nodesetval);
    }
    xmlFree(obj);
    }
    xmlPointerListFree(list);
}
 
static void
xmlXPathFreeCache(xmlXPathContextCachePtr cache)
{
    if (cache == NULL)
    return;
    if (cache->nodesetObjs)
    xmlXPathCacheFreeObjectList(cache->nodesetObjs);
    if (cache->stringObjs)
    xmlXPathCacheFreeObjectList(cache->stringObjs);
    if (cache->booleanObjs)
    xmlXPathCacheFreeObjectList(cache->booleanObjs);
    if (cache->numberObjs)
    xmlXPathCacheFreeObjectList(cache->numberObjs);
    if (cache->miscObjs)
    xmlXPathCacheFreeObjectList(cache->miscObjs);
    xmlFree(cache);
}
 
int
xmlXPathContextSetCache(xmlXPathContextPtr ctxt,
            int active,
            int value,
            int options)
{
    if (ctxt == NULL)
    return(-1);
    if (active) {
    xmlXPathContextCachePtr cache;
 
    if (ctxt->cache == NULL) {
        ctxt->cache = xmlXPathNewCache();
        if (ctxt->cache == NULL)
        return(-1);
    }
    cache = (xmlXPathContextCachePtr) ctxt->cache;
    if (options == 0) {
        if (value < 0)
        value = 100;
        cache->maxNodeset = value;
        cache->maxString = value;
        cache->maxNumber = value;
        cache->maxBoolean = value;
        cache->maxMisc = value;
    }
    } else if (ctxt->cache != NULL) {
    xmlXPathFreeCache((xmlXPathContextCachePtr) ctxt->cache);
    ctxt->cache = NULL;
    }
    return(0);
}
 
static xmlXPathObjectPtr
xmlXPathCacheWrapNodeSet(xmlXPathContextPtr ctxt, xmlNodeSetPtr val)
{
    if ((ctxt != NULL) && (ctxt->cache != NULL)) {
    xmlXPathContextCachePtr cache =
        (xmlXPathContextCachePtr) ctxt->cache;
 
    if ((cache->miscObjs != NULL) &&
        (cache->miscObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
 
        ret = (xmlXPathObjectPtr)
        cache->miscObjs->items[--cache->miscObjs->number];
        ret->type = XPATH_NODESET;
        ret->nodesetval = val;
        return(ret);
    }
    }
 
    return(xmlXPathWrapNodeSet(val));
 
}
 
static xmlXPathObjectPtr
xmlXPathCacheWrapString(xmlXPathContextPtr ctxt, xmlChar *val)
{
    if ((ctxt != NULL) && (ctxt->cache != NULL)) {
    xmlXPathContextCachePtr cache = (xmlXPathContextCachePtr) ctxt->cache;
 
    if ((cache->stringObjs != NULL) &&
        (cache->stringObjs->number != 0))
    {
 
        xmlXPathObjectPtr ret;
 
        ret = (xmlXPathObjectPtr)
        cache->stringObjs->items[--cache->stringObjs->number];
        ret->type = XPATH_STRING;
        ret->stringval = val;
        return(ret);
    } else if ((cache->miscObjs != NULL) &&
        (cache->miscObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
        /*
        * Fallback to misc-cache.
        */
        ret = (xmlXPathObjectPtr)
        cache->miscObjs->items[--cache->miscObjs->number];
 
        ret->type = XPATH_STRING;
        ret->stringval = val;
        return(ret);
    }
    }
    return(xmlXPathWrapString(val));
}
 
static xmlXPathObjectPtr
xmlXPathCacheNewNodeSet(xmlXPathContextPtr ctxt, xmlNodePtr val)
{
    if ((ctxt != NULL) && (ctxt->cache)) {
    xmlXPathContextCachePtr cache = (xmlXPathContextCachePtr) ctxt->cache;
 
    if ((cache->nodesetObjs != NULL) &&
        (cache->nodesetObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
        /*
        * Use the nodeset-cache.
        */
        ret = (xmlXPathObjectPtr)
        cache->nodesetObjs->items[--cache->nodesetObjs->number];
        ret->type = XPATH_NODESET;
        ret->boolval = 0;
        if (val) {
        if ((ret->nodesetval->nodeMax == 0) ||
            (val->type == XML_NAMESPACE_DECL))
        {
                    /* TODO: Check memory error. */
            xmlXPathNodeSetAddUnique(ret->nodesetval, val);
        } else {
            ret->nodesetval->nodeTab[0] = val;
            ret->nodesetval->nodeNr = 1;
        }
        }
        return(ret);
    } else if ((cache->miscObjs != NULL) &&
        (cache->miscObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
            xmlNodeSetPtr set;
        /*
        * Fallback to misc-cache.
        */
 
        set = xmlXPathNodeSetCreate(val);
        if (set == NULL) {
        ctxt->lastError.domain = XML_FROM_XPATH;
        ctxt->lastError.code = XML_ERR_NO_MEMORY;
        return(NULL);
        }
 
        ret = (xmlXPathObjectPtr)
        cache->miscObjs->items[--cache->miscObjs->number];
 
        ret->type = XPATH_NODESET;
        ret->boolval = 0;
        ret->nodesetval = set;
        return(ret);
    }
    }
    return(xmlXPathNewNodeSet(val));
}
 
static xmlXPathObjectPtr
xmlXPathCacheNewString(xmlXPathContextPtr ctxt, const xmlChar *val)
{
    if ((ctxt != NULL) && (ctxt->cache)) {
    xmlXPathContextCachePtr cache = (xmlXPathContextCachePtr) ctxt->cache;
 
    if ((cache->stringObjs != NULL) &&
        (cache->stringObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
            xmlChar *copy;
 
            if (val == NULL)
                val = BAD_CAST "";
            copy = xmlStrdup(val);
            if (copy == NULL) {
                xmlXPathErrMemory(ctxt, NULL);
                return(NULL);
            }
 
        ret = (xmlXPathObjectPtr)
        cache->stringObjs->items[--cache->stringObjs->number];
        ret->type = XPATH_STRING;
            ret->stringval = copy;
        return(ret);
    } else if ((cache->miscObjs != NULL) &&
        (cache->miscObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
            xmlChar *copy;
 
            if (val == NULL)
                val = BAD_CAST "";
            copy = xmlStrdup(val);
            if (copy == NULL) {
                xmlXPathErrMemory(ctxt, NULL);
                return(NULL);
            }
 
        ret = (xmlXPathObjectPtr)
        cache->miscObjs->items[--cache->miscObjs->number];
 
        ret->type = XPATH_STRING;
            ret->stringval = copy;
        return(ret);
    }
    }
    return(xmlXPathNewString(val));
}
 
static xmlXPathObjectPtr
xmlXPathCacheNewCString(xmlXPathContextPtr ctxt, const char *val)
{
    return xmlXPathCacheNewString(ctxt, BAD_CAST val);
}
 
static xmlXPathObjectPtr
xmlXPathCacheNewBoolean(xmlXPathContextPtr ctxt, int val)
{
    if ((ctxt != NULL) && (ctxt->cache)) {
    xmlXPathContextCachePtr cache = (xmlXPathContextCachePtr) ctxt->cache;
 
    if ((cache->booleanObjs != NULL) &&
        (cache->booleanObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
 
        ret = (xmlXPathObjectPtr)
        cache->booleanObjs->items[--cache->booleanObjs->number];
        ret->type = XPATH_BOOLEAN;
        ret->boolval = (val != 0);
        return(ret);
    } else if ((cache->miscObjs != NULL) &&
        (cache->miscObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
 
        ret = (xmlXPathObjectPtr)
        cache->miscObjs->items[--cache->miscObjs->number];
 
        ret->type = XPATH_BOOLEAN;
        ret->boolval = (val != 0);
        return(ret);
    }
    }
    return(xmlXPathNewBoolean(val));
}
 
static xmlXPathObjectPtr
xmlXPathCacheNewFloat(xmlXPathContextPtr ctxt, double val)
{
     if ((ctxt != NULL) && (ctxt->cache)) {
    xmlXPathContextCachePtr cache = (xmlXPathContextCachePtr) ctxt->cache;
 
    if ((cache->numberObjs != NULL) &&
        (cache->numberObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
 
        ret = (xmlXPathObjectPtr)
        cache->numberObjs->items[--cache->numberObjs->number];
        ret->type = XPATH_NUMBER;
        ret->floatval = val;
        return(ret);
    } else if ((cache->miscObjs != NULL) &&
        (cache->miscObjs->number != 0))
    {
        xmlXPathObjectPtr ret;
 
        ret = (xmlXPathObjectPtr)
        cache->miscObjs->items[--cache->miscObjs->number];
 
        ret->type = XPATH_NUMBER;
        ret->floatval = val;
        return(ret);
    }
    }
    return(xmlXPathNewFloat(val));
}
 
static xmlXPathObjectPtr
xmlXPathCacheConvertString(xmlXPathContextPtr ctxt, xmlXPathObjectPtr val) {
    xmlChar *res = NULL;
 
    if (val == NULL)
    return(xmlXPathCacheNewCString(ctxt, ""));
 
    switch (val->type) {
    case XPATH_UNDEFINED:
    break;
    case XPATH_NODESET:
    case XPATH_XSLT_TREE:
    res = xmlXPathCastNodeSetToString(val->nodesetval);
    break;
    case XPATH_STRING:
    return(val);
    case XPATH_BOOLEAN:
    res = xmlXPathCastBooleanToString(val->boolval);
    break;
    case XPATH_NUMBER:
    res = xmlXPathCastNumberToString(val->floatval);
    break;
    case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_POINT:
    case XPATH_RANGE:
    case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
    TODO;
    break;
    }
    xmlXPathReleaseObject(ctxt, val);
    if (res == NULL)
    return(xmlXPathCacheNewCString(ctxt, ""));
    return(xmlXPathCacheWrapString(ctxt, res));
}
 
static xmlXPathObjectPtr
xmlXPathCacheObjectCopy(xmlXPathContextPtr ctxt, xmlXPathObjectPtr val)
{
    if (val == NULL)
    return(NULL);
 
    if (XP_HAS_CACHE(ctxt)) {
    switch (val->type) {
        case XPATH_NODESET:
        return(xmlXPathCacheWrapNodeSet(ctxt,
            xmlXPathNodeSetMerge(NULL, val->nodesetval)));
        case XPATH_STRING:
        return(xmlXPathCacheNewString(ctxt, val->stringval));
        case XPATH_BOOLEAN:
        return(xmlXPathCacheNewBoolean(ctxt, val->boolval));
        case XPATH_NUMBER:
        return(xmlXPathCacheNewFloat(ctxt, val->floatval));
        default:
        break;
    }
    }
    return(xmlXPathObjectCopy(val));
}
 
static xmlXPathObjectPtr
xmlXPathCacheConvertBoolean(xmlXPathContextPtr ctxt, xmlXPathObjectPtr val) {
    xmlXPathObjectPtr ret;
 
    if (val == NULL)
    return(xmlXPathCacheNewBoolean(ctxt, 0));
    if (val->type == XPATH_BOOLEAN)
    return(val);
    ret = xmlXPathCacheNewBoolean(ctxt, xmlXPathCastToBoolean(val));
    xmlXPathReleaseObject(ctxt, val);
    return(ret);
}
 
static xmlXPathObjectPtr
xmlXPathCacheConvertNumber(xmlXPathContextPtr ctxt, xmlXPathObjectPtr val) {
    xmlXPathObjectPtr ret;
 
    if (val == NULL)
    return(xmlXPathCacheNewFloat(ctxt, 0.0));
    if (val->type == XPATH_NUMBER)
    return(val);
    ret = xmlXPathCacheNewFloat(ctxt, xmlXPathCastToNumber(val));
    xmlXPathReleaseObject(ctxt, val);
    return(ret);
}
 
/************************************************************************
 *                                  *
 *      Parser stacks related functions and macros      *
 *                                  *
 ************************************************************************/
 
xmlXPathObjectPtr
valuePop(xmlXPathParserContextPtr ctxt)
{
    xmlXPathObjectPtr ret;
 
    if ((ctxt == NULL) || (ctxt->valueNr <= 0))
        return (NULL);
 
    ctxt->valueNr--;
    if (ctxt->valueNr > 0)
        ctxt->value = ctxt->valueTab[ctxt->valueNr - 1];
    else
        ctxt->value = NULL;
    ret = ctxt->valueTab[ctxt->valueNr];
    ctxt->valueTab[ctxt->valueNr] = NULL;
    return (ret);
}
int
valuePush(xmlXPathParserContextPtr ctxt, xmlXPathObjectPtr value)
{
    if (ctxt == NULL) return(-1);
    if (value == NULL) {
        /*
         * A NULL value typically indicates that a memory allocation failed,
         * so we set ctxt->error here to propagate the error.
         */
    ctxt->error = XPATH_MEMORY_ERROR;
        return(-1);
    }
    if (ctxt->valueNr >= ctxt->valueMax) {
        xmlXPathObjectPtr *tmp;
 
        if (ctxt->valueMax >= XPATH_MAX_STACK_DEPTH) {
            xmlXPathPErrMemory(ctxt, "XPath stack depth limit reached\n");
            xmlXPathFreeObject(value);
            return (-1);
        }
        tmp = (xmlXPathObjectPtr *) xmlRealloc(ctxt->valueTab,
                                             2 * ctxt->valueMax *
                                             sizeof(ctxt->valueTab[0]));
        if (tmp == NULL) {
            xmlXPathPErrMemory(ctxt, "pushing value\n");
            xmlXPathFreeObject(value);
            return (-1);
        }
        ctxt->valueMax *= 2;
    ctxt->valueTab = tmp;
    }
    ctxt->valueTab[ctxt->valueNr] = value;
    ctxt->value = value;
    return (ctxt->valueNr++);
}
 
int
xmlXPathPopBoolean (xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr obj;
    int ret;
 
    obj = valuePop(ctxt);
    if (obj == NULL) {
    xmlXPathSetError(ctxt, XPATH_INVALID_OPERAND);
    return(0);
    }
    if (obj->type != XPATH_BOOLEAN)
    ret = xmlXPathCastToBoolean(obj);
    else
        ret = obj->boolval;
    xmlXPathReleaseObject(ctxt->context, obj);
    return(ret);
}
 
double
xmlXPathPopNumber (xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr obj;
    double ret;
 
    obj = valuePop(ctxt);
    if (obj == NULL) {
    xmlXPathSetError(ctxt, XPATH_INVALID_OPERAND);
    return(0);
    }
    if (obj->type != XPATH_NUMBER)
    ret = xmlXPathCastToNumber(obj);
    else
        ret = obj->floatval;
    xmlXPathReleaseObject(ctxt->context, obj);
    return(ret);
}
 
xmlChar *
xmlXPathPopString (xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr obj;
    xmlChar * ret;
 
    obj = valuePop(ctxt);
    if (obj == NULL) {
    xmlXPathSetError(ctxt, XPATH_INVALID_OPERAND);
    return(NULL);
    }
    ret = xmlXPathCastToString(obj);    /* this does required strdup */
    /* TODO: needs refactoring somewhere else */
    if (obj->stringval == ret)
    obj->stringval = NULL;
    xmlXPathReleaseObject(ctxt->context, obj);
    return(ret);
}
 
xmlNodeSetPtr
xmlXPathPopNodeSet (xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr obj;
    xmlNodeSetPtr ret;
 
    if (ctxt == NULL) return(NULL);
    if (ctxt->value == NULL) {
    xmlXPathSetError(ctxt, XPATH_INVALID_OPERAND);
    return(NULL);
    }
    if (!xmlXPathStackIsNodeSet(ctxt)) {
    xmlXPathSetTypeError(ctxt);
    return(NULL);
    }
    obj = valuePop(ctxt);
    ret = obj->nodesetval;
#if 0
    /* to fix memory leak of not clearing obj->user */
    if (obj->boolval && obj->user != NULL)
        xmlFreeNodeList((xmlNodePtr) obj->user);
#endif
    obj->nodesetval = NULL;
    xmlXPathReleaseObject(ctxt->context, obj);
    return(ret);
}
 
void *
xmlXPathPopExternal (xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr obj;
    void * ret;
 
    if ((ctxt == NULL) || (ctxt->value == NULL)) {
    xmlXPathSetError(ctxt, XPATH_INVALID_OPERAND);
    return(NULL);
    }
    if (ctxt->value->type != XPATH_USERS) {
    xmlXPathSetTypeError(ctxt);
    return(NULL);
    }
    obj = valuePop(ctxt);
    ret = obj->user;
    obj->user = NULL;
    xmlXPathReleaseObject(ctxt->context, obj);
    return(ret);
}
 
/*
 * Macros for accessing the content. Those should be used only by the parser,
 * and not exported.
 *
 * Dirty macros, i.e. one need to make assumption on the context to use them
 *
 *   CUR_PTR return the current pointer to the xmlChar to be parsed.
 *   CUR     returns the current xmlChar value, i.e. a 8 bit value
 *           in ISO-Latin or UTF-8.
 *           This should be used internally by the parser
 *           only to compare to ASCII values otherwise it would break when
 *           running with UTF-8 encoding.
 *   NXT(n)  returns the n'th next xmlChar. Same as CUR is should be used only
 *           to compare on ASCII based substring.
 *   SKIP(n) Skip n xmlChar, and must also be used only to skip ASCII defined
 *           strings within the parser.
 *   CURRENT Returns the current char value, with the full decoding of
 *           UTF-8 if we are using this mode. It returns an int.
 *   NEXT    Skip to the next character, this does the proper decoding
 *           in UTF-8 mode. It also pop-up unfinished entities on the fly.
 *           It returns the pointer to the current xmlChar.
 */
 
#define CUR (*ctxt->cur)
#define SKIP(val) ctxt->cur += (val)
#define NXT(val) ctxt->cur[(val)]
#define CUR_PTR ctxt->cur
#define CUR_CHAR(l) xmlXPathCurrentChar(ctxt, &l)
 
#define COPY_BUF(l,b,i,v)                                              \
    if (l == 1) b[i++] = v;                                            \
    else i += xmlCopyChar(l,&b[i],v)
 
#define NEXTL(l)  ctxt->cur += l
 
#define SKIP_BLANKS                         \
    while (IS_BLANK_CH(*(ctxt->cur))) NEXT
 
#define CURRENT (*ctxt->cur)
#define NEXT ((*ctxt->cur) ?  ctxt->cur++: ctxt->cur)
 
 
#ifndef DBL_DIG
#define DBL_DIG 16
#endif
#ifndef DBL_EPSILON
#define DBL_EPSILON 1E-9
#endif
 
#define UPPER_DOUBLE 1E9
#define LOWER_DOUBLE 1E-5
#define LOWER_DOUBLE_EXP 5
 
#define INTEGER_DIGITS DBL_DIG
#define FRACTION_DIGITS (DBL_DIG + 1 + (LOWER_DOUBLE_EXP))
#define EXPONENT_DIGITS (3 + 2)
 
static void
xmlXPathFormatNumber(double number, char buffer[], int buffersize)
{
    switch (xmlXPathIsInf(number)) {
    case 1:
    if (buffersize > (int)sizeof("Infinity"))
        snprintf(buffer, buffersize, "Infinity");
    break;
    case -1:
    if (buffersize > (int)sizeof("-Infinity"))
        snprintf(buffer, buffersize, "-Infinity");
    break;
    default:
    if (xmlXPathIsNaN(number)) {
        if (buffersize > (int)sizeof("NaN"))
        snprintf(buffer, buffersize, "NaN");
    } else if (number == 0) {
            /* Omit sign for negative zero. */
        snprintf(buffer, buffersize, "0");
    } else if ((number > INT_MIN) && (number < INT_MAX) &&
                   (number == (int) number)) {
        char work[30];
        char *ptr, *cur;
        int value = (int) number;
 
            ptr = &buffer[0];
        if (value == 0) {
        *ptr++ = '0';
        } else {
        snprintf(work, 29, "%d", value);
        cur = &work[0];
        while ((*cur) && (ptr - buffer < buffersize)) {
            *ptr++ = *cur++;
        }
        }
        if (ptr - buffer < buffersize) {
        *ptr = 0;
        } else if (buffersize > 0) {
        ptr--;
        *ptr = 0;
        }
    } else {
        /*
          For the dimension of work,
              DBL_DIG is number of significant digits
          EXPONENT is only needed for "scientific notation"
              3 is sign, decimal point, and terminating zero
          LOWER_DOUBLE_EXP is max number of leading zeroes in fraction
          Note that this dimension is slightly (a few characters)
          larger than actually necessary.
        */
        char work[DBL_DIG + EXPONENT_DIGITS + 3 + LOWER_DOUBLE_EXP];
        int integer_place, fraction_place;
        char *ptr;
        char *after_fraction;
        double absolute_value;
        int size;
 
        absolute_value = fabs(number);
 
        /*
         * First choose format - scientific or regular floating point.
         * In either case, result is in work, and after_fraction points
         * just past the fractional part.
        */
        if ( ((absolute_value > UPPER_DOUBLE) ||
          (absolute_value < LOWER_DOUBLE)) &&
         (absolute_value != 0.0) ) {
        /* Use scientific notation */
        integer_place = DBL_DIG + EXPONENT_DIGITS + 1;
        fraction_place = DBL_DIG - 1;
        size = snprintf(work, sizeof(work),"%*.*e",
             integer_place, fraction_place, number);
        while ((size > 0) && (work[size] != 'e')) size--;
 
        }
        else {
        /* Use regular notation */
        if (absolute_value > 0.0) {
            integer_place = (int)log10(absolute_value);
            if (integer_place > 0)
                fraction_place = DBL_DIG - integer_place - 1;
            else
                fraction_place = DBL_DIG - integer_place;
        } else {
            fraction_place = 1;
        }
        size = snprintf(work, sizeof(work), "%0.*f",
                fraction_place, number);
        }
 
        /* Remove leading spaces sometimes inserted by snprintf */
        while (work[0] == ' ') {
            for (ptr = &work[0];(ptr[0] = ptr[1]);ptr++);
        size--;
        }
 
        /* Remove fractional trailing zeroes */
        after_fraction = work + size;
        ptr = after_fraction;
        while (*(--ptr) == '0')
        ;
        if (*ptr != '.')
            ptr++;
        while ((*ptr++ = *after_fraction++) != 0);
 
        /* Finally copy result back to caller */
        size = strlen(work) + 1;
        if (size > buffersize) {
        work[buffersize - 1] = 0;
        size = buffersize;
        }
        memmove(buffer, work, size);
    }
    break;
    }
}
 
 
/************************************************************************
 *                                  *
 *          Routines to handle NodeSets         *
 *                                  *
 ************************************************************************/
 
long
xmlXPathOrderDocElems(xmlDocPtr doc) {
    ptrdiff_t count = 0;
    xmlNodePtr cur;
 
    if (doc == NULL)
    return(-1);
    cur = doc->children;
    while (cur != NULL) {
    if (cur->type == XML_ELEMENT_NODE) {
        cur->content = (void *) (-(++count));
        if (cur->children != NULL) {
        cur = cur->children;
        continue;
        }
    }
    if (cur->next != NULL) {
        cur = cur->next;
        continue;
    }
    do {
        cur = cur->parent;
        if (cur == NULL)
        break;
        if (cur == (xmlNodePtr) doc) {
        cur = NULL;
        break;
        }
        if (cur->next != NULL) {
        cur = cur->next;
        break;
        }
    } while (cur != NULL);
    }
    return(count);
}
 
int
xmlXPathCmpNodes(xmlNodePtr node1, xmlNodePtr node2) {
    int depth1, depth2;
    int attr1 = 0, attr2 = 0;
    xmlNodePtr attrNode1 = NULL, attrNode2 = NULL;
    xmlNodePtr cur, root;
 
    if ((node1 == NULL) || (node2 == NULL))
    return(-2);
    /*
     * a couple of optimizations which will avoid computations in most cases
     */
    if (node1 == node2)     /* trivial case */
    return(0);
    if (node1->type == XML_ATTRIBUTE_NODE) {
    attr1 = 1;
    attrNode1 = node1;
    node1 = node1->parent;
    }
    if (node2->type == XML_ATTRIBUTE_NODE) {
    attr2 = 1;
    attrNode2 = node2;
    node2 = node2->parent;
    }
    if (node1 == node2) {
    if (attr1 == attr2) {
        /* not required, but we keep attributes in order */
        if (attr1 != 0) {
            cur = attrNode2->prev;
        while (cur != NULL) {
            if (cur == attrNode1)
                return (1);
            cur = cur->prev;
        }
        return (-1);
        }
        return(0);
    }
    if (attr2 == 1)
        return(1);
    return(-1);
    }
    if ((node1->type == XML_NAMESPACE_DECL) ||
        (node2->type == XML_NAMESPACE_DECL))
    return(1);
    if (node1 == node2->prev)
    return(1);
    if (node1 == node2->next)
    return(-1);
 
    /*
     * Speedup using document order if available.
     */
    if ((node1->type == XML_ELEMENT_NODE) &&
    (node2->type == XML_ELEMENT_NODE) &&
    (0 > (ptrdiff_t) node1->content) &&
    (0 > (ptrdiff_t) node2->content) &&
    (node1->doc == node2->doc)) {
    ptrdiff_t l1, l2;
 
    l1 = -((ptrdiff_t) node1->content);
    l2 = -((ptrdiff_t) node2->content);
    if (l1 < l2)
        return(1);
    if (l1 > l2)
        return(-1);
    }
 
    /*
     * compute depth to root
     */
    for (depth2 = 0, cur = node2;cur->parent != NULL;cur = cur->parent) {
    if (cur->parent == node1)
        return(1);
    depth2++;
    }
    root = cur;
    for (depth1 = 0, cur = node1;cur->parent != NULL;cur = cur->parent) {
    if (cur->parent == node2)
        return(-1);
    depth1++;
    }
    /*
     * Distinct document (or distinct entities :-( ) case.
     */
    if (root != cur) {
    return(-2);
    }
    /*
     * get the nearest common ancestor.
     */
    while (depth1 > depth2) {
    depth1--;
    node1 = node1->parent;
    }
    while (depth2 > depth1) {
    depth2--;
    node2 = node2->parent;
    }
    while (node1->parent != node2->parent) {
    node1 = node1->parent;
    node2 = node2->parent;
    /* should not happen but just in case ... */
    if ((node1 == NULL) || (node2 == NULL))
        return(-2);
    }
    /*
     * Find who's first.
     */
    if (node1 == node2->prev)
    return(1);
    if (node1 == node2->next)
    return(-1);
    /*
     * Speedup using document order if available.
     */
    if ((node1->type == XML_ELEMENT_NODE) &&
    (node2->type == XML_ELEMENT_NODE) &&
    (0 > (ptrdiff_t) node1->content) &&
    (0 > (ptrdiff_t) node2->content) &&
    (node1->doc == node2->doc)) {
    ptrdiff_t l1, l2;
 
    l1 = -((ptrdiff_t) node1->content);
    l2 = -((ptrdiff_t) node2->content);
    if (l1 < l2)
        return(1);
    if (l1 > l2)
        return(-1);
    }
 
    for (cur = node1->next;cur != NULL;cur = cur->next)
    if (cur == node2)
        return(1);
    return(-1); /* assume there is no sibling list corruption */
}
 
void
xmlXPathNodeSetSort(xmlNodeSetPtr set) {
#ifndef WITH_TIM_SORT
    int i, j, incr, len;
    xmlNodePtr tmp;
#endif
 
    if (set == NULL)
    return;
 
#ifndef WITH_TIM_SORT
    /*
     * Use the old Shell's sort implementation to sort the node-set
     * Timsort ought to be quite faster
     */
    len = set->nodeNr;
    for (incr = len / 2; incr > 0; incr /= 2) {
    for (i = incr; i < len; i++) {
        j = i - incr;
        while (j >= 0) {
#ifdef XP_OPTIMIZED_NON_ELEM_COMPARISON
        if (xmlXPathCmpNodesExt(set->nodeTab[j],
            set->nodeTab[j + incr]) == -1)
#else
        if (xmlXPathCmpNodes(set->nodeTab[j],
            set->nodeTab[j + incr]) == -1)
#endif
        {
            tmp = set->nodeTab[j];
            set->nodeTab[j] = set->nodeTab[j + incr];
            set->nodeTab[j + incr] = tmp;
            j -= incr;
        } else
            break;
        }
    }
    }
#else /* WITH_TIM_SORT */
    libxml_domnode_tim_sort(set->nodeTab, set->nodeNr);
#endif /* WITH_TIM_SORT */
}
 
#define XML_NODESET_DEFAULT 10
static xmlNodePtr
xmlXPathNodeSetDupNs(xmlNodePtr node, xmlNsPtr ns) {
    xmlNsPtr cur;
 
    if ((ns == NULL) || (ns->type != XML_NAMESPACE_DECL))
    return(NULL);
    if ((node == NULL) || (node->type == XML_NAMESPACE_DECL))
    return((xmlNodePtr) ns);
 
    /*
     * Allocate a new Namespace and fill the fields.
     */
    cur = (xmlNsPtr) xmlMalloc(sizeof(xmlNs));
    if (cur == NULL) {
        xmlXPathErrMemory(NULL, "duplicating namespace\n");
    return(NULL);
    }
    memset(cur, 0, sizeof(xmlNs));
    cur->type = XML_NAMESPACE_DECL;
    if (ns->href != NULL)
    cur->href = xmlStrdup(ns->href);
    if (ns->prefix != NULL)
    cur->prefix = xmlStrdup(ns->prefix);
    cur->next = (xmlNsPtr) node;
    return((xmlNodePtr) cur);
}
 
void
xmlXPathNodeSetFreeNs(xmlNsPtr ns) {
    if ((ns == NULL) || (ns->type != XML_NAMESPACE_DECL))
    return;
 
    if ((ns->next != NULL) && (ns->next->type != XML_NAMESPACE_DECL)) {
    if (ns->href != NULL)
        xmlFree((xmlChar *)ns->href);
    if (ns->prefix != NULL)
        xmlFree((xmlChar *)ns->prefix);
    xmlFree(ns);
    }
}
 
xmlNodeSetPtr
xmlXPathNodeSetCreate(xmlNodePtr val) {
    xmlNodeSetPtr ret;
 
    ret = (xmlNodeSetPtr) xmlMalloc(sizeof(xmlNodeSet));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating nodeset\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlNodeSet));
    if (val != NULL) {
        ret->nodeTab = (xmlNodePtr *) xmlMalloc(XML_NODESET_DEFAULT *
                         sizeof(xmlNodePtr));
    if (ret->nodeTab == NULL) {
        xmlXPathErrMemory(NULL, "creating nodeset\n");
        xmlFree(ret);
        return(NULL);
    }
    memset(ret->nodeTab, 0 ,
           XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        ret->nodeMax = XML_NODESET_DEFAULT;
    if (val->type == XML_NAMESPACE_DECL) {
        xmlNsPtr ns = (xmlNsPtr) val;
            xmlNodePtr nsNode = xmlXPathNodeSetDupNs((xmlNodePtr) ns->next, ns);
 
            if (nsNode == NULL) {
                xmlXPathFreeNodeSet(ret);
                return(NULL);
            }
        ret->nodeTab[ret->nodeNr++] = nsNode;
    } else
        ret->nodeTab[ret->nodeNr++] = val;
    }
    return(ret);
}
 
int
xmlXPathNodeSetContains (xmlNodeSetPtr cur, xmlNodePtr val) {
    int i;
 
    if ((cur == NULL) || (val == NULL)) return(0);
    if (val->type == XML_NAMESPACE_DECL) {
    for (i = 0; i < cur->nodeNr; i++) {
        if (cur->nodeTab[i]->type == XML_NAMESPACE_DECL) {
        xmlNsPtr ns1, ns2;
 
        ns1 = (xmlNsPtr) val;
        ns2 = (xmlNsPtr) cur->nodeTab[i];
        if (ns1 == ns2)
            return(1);
        if ((ns1->next != NULL) && (ns2->next == ns1->next) &&
                (xmlStrEqual(ns1->prefix, ns2->prefix)))
            return(1);
        }
    }
    } else {
    for (i = 0; i < cur->nodeNr; i++) {
        if (cur->nodeTab[i] == val)
        return(1);
    }
    }
    return(0);
}
 
int
xmlXPathNodeSetAddNs(xmlNodeSetPtr cur, xmlNodePtr node, xmlNsPtr ns) {
    int i;
    xmlNodePtr nsNode;
 
    if ((cur == NULL) || (ns == NULL) || (node == NULL) ||
        (ns->type != XML_NAMESPACE_DECL) ||
    (node->type != XML_ELEMENT_NODE))
    return(-1);
 
    /* @@ with_ns to check whether namespace nodes should be looked at @@ */
    /*
     * prevent duplicates
     */
    for (i = 0;i < cur->nodeNr;i++) {
        if ((cur->nodeTab[i] != NULL) &&
        (cur->nodeTab[i]->type == XML_NAMESPACE_DECL) &&
        (((xmlNsPtr)cur->nodeTab[i])->next == (xmlNsPtr) node) &&
        (xmlStrEqual(ns->prefix, ((xmlNsPtr)cur->nodeTab[i])->prefix)))
        return(0);
    }
 
    /*
     * grow the nodeTab if needed
     */
    if (cur->nodeMax == 0) {
        cur->nodeTab = (xmlNodePtr *) xmlMalloc(XML_NODESET_DEFAULT *
                         sizeof(xmlNodePtr));
    if (cur->nodeTab == NULL) {
        xmlXPathErrMemory(NULL, "growing nodeset\n");
        return(-1);
    }
    memset(cur->nodeTab, 0 ,
           XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        cur->nodeMax = XML_NODESET_DEFAULT;
    } else if (cur->nodeNr == cur->nodeMax) {
        xmlNodePtr *temp;
 
        if (cur->nodeMax >= XPATH_MAX_NODESET_LENGTH) {
            xmlXPathErrMemory(NULL, "growing nodeset hit limit\n");
            return(-1);
        }
    temp = (xmlNodePtr *) xmlRealloc(cur->nodeTab, cur->nodeMax * 2 *
                      sizeof(xmlNodePtr));
    if (temp == NULL) {
        xmlXPathErrMemory(NULL, "growing nodeset\n");
        return(-1);
    }
        cur->nodeMax *= 2;
    cur->nodeTab = temp;
    }
    nsNode = xmlXPathNodeSetDupNs(node, ns);
    if(nsNode == NULL)
        return(-1);
    cur->nodeTab[cur->nodeNr++] = nsNode;
    return(0);
}
 
int
xmlXPathNodeSetAdd(xmlNodeSetPtr cur, xmlNodePtr val) {
    int i;
 
    if ((cur == NULL) || (val == NULL)) return(-1);
 
    /* @@ with_ns to check whether namespace nodes should be looked at @@ */
    /*
     * prevent duplicates
     */
    for (i = 0;i < cur->nodeNr;i++)
        if (cur->nodeTab[i] == val) return(0);
 
    /*
     * grow the nodeTab if needed
     */
    if (cur->nodeMax == 0) {
        cur->nodeTab = (xmlNodePtr *) xmlMalloc(XML_NODESET_DEFAULT *
                         sizeof(xmlNodePtr));
    if (cur->nodeTab == NULL) {
        xmlXPathErrMemory(NULL, "growing nodeset\n");
        return(-1);
    }
    memset(cur->nodeTab, 0 ,
           XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        cur->nodeMax = XML_NODESET_DEFAULT;
    } else if (cur->nodeNr == cur->nodeMax) {
        xmlNodePtr *temp;
 
        if (cur->nodeMax >= XPATH_MAX_NODESET_LENGTH) {
            xmlXPathErrMemory(NULL, "growing nodeset hit limit\n");
            return(-1);
        }
    temp = (xmlNodePtr *) xmlRealloc(cur->nodeTab, cur->nodeMax * 2 *
                      sizeof(xmlNodePtr));
    if (temp == NULL) {
        xmlXPathErrMemory(NULL, "growing nodeset\n");
        return(-1);
    }
        cur->nodeMax *= 2;
    cur->nodeTab = temp;
    }
    if (val->type == XML_NAMESPACE_DECL) {
    xmlNsPtr ns = (xmlNsPtr) val;
        xmlNodePtr nsNode = xmlXPathNodeSetDupNs((xmlNodePtr) ns->next, ns);
 
        if (nsNode == NULL)
            return(-1);
    cur->nodeTab[cur->nodeNr++] = nsNode;
    } else
    cur->nodeTab[cur->nodeNr++] = val;
    return(0);
}
 
int
xmlXPathNodeSetAddUnique(xmlNodeSetPtr cur, xmlNodePtr val) {
    if ((cur == NULL) || (val == NULL)) return(-1);
 
    /* @@ with_ns to check whether namespace nodes should be looked at @@ */
    /*
     * grow the nodeTab if needed
     */
    if (cur->nodeMax == 0) {
        cur->nodeTab = (xmlNodePtr *) xmlMalloc(XML_NODESET_DEFAULT *
                         sizeof(xmlNodePtr));
    if (cur->nodeTab == NULL) {
        xmlXPathErrMemory(NULL, "growing nodeset\n");
        return(-1);
    }
    memset(cur->nodeTab, 0 ,
           XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        cur->nodeMax = XML_NODESET_DEFAULT;
    } else if (cur->nodeNr == cur->nodeMax) {
        xmlNodePtr *temp;
 
        if (cur->nodeMax >= XPATH_MAX_NODESET_LENGTH) {
            xmlXPathErrMemory(NULL, "growing nodeset hit limit\n");
            return(-1);
        }
    temp = (xmlNodePtr *) xmlRealloc(cur->nodeTab, cur->nodeMax * 2 *
                      sizeof(xmlNodePtr));
    if (temp == NULL) {
        xmlXPathErrMemory(NULL, "growing nodeset\n");
        return(-1);
    }
    cur->nodeTab = temp;
        cur->nodeMax *= 2;
    }
    if (val->type == XML_NAMESPACE_DECL) {
    xmlNsPtr ns = (xmlNsPtr) val;
        xmlNodePtr nsNode = xmlXPathNodeSetDupNs((xmlNodePtr) ns->next, ns);
 
        if (nsNode == NULL)
            return(-1);
    cur->nodeTab[cur->nodeNr++] = nsNode;
    } else
    cur->nodeTab[cur->nodeNr++] = val;
    return(0);
}
 
xmlNodeSetPtr
xmlXPathNodeSetMerge(xmlNodeSetPtr val1, xmlNodeSetPtr val2) {
    int i, j, initNr, skip;
    xmlNodePtr n1, n2;
 
    if (val2 == NULL) return(val1);
    if (val1 == NULL) {
    val1 = xmlXPathNodeSetCreate(NULL);
        if (val1 == NULL)
            return (NULL);
    }
 
    /* @@ with_ns to check whether namespace nodes should be looked at @@ */
    initNr = val1->nodeNr;
 
    for (i = 0;i < val2->nodeNr;i++) {
    n2 = val2->nodeTab[i];
    /*
     * check against duplicates
     */
    skip = 0;
    for (j = 0; j < initNr; j++) {
        n1 = val1->nodeTab[j];
        if (n1 == n2) {
        skip = 1;
        break;
        } else if ((n1->type == XML_NAMESPACE_DECL) &&
               (n2->type == XML_NAMESPACE_DECL)) {
        if ((((xmlNsPtr) n1)->next == ((xmlNsPtr) n2)->next) &&
            (xmlStrEqual(((xmlNsPtr) n1)->prefix,
            ((xmlNsPtr) n2)->prefix)))
        {
            skip = 1;
            break;
        }
        }
    }
    if (skip)
        continue;
 
    /*
     * grow the nodeTab if needed
     */
    if (val1->nodeMax == 0) {
        val1->nodeTab = (xmlNodePtr *) xmlMalloc(XML_NODESET_DEFAULT *
                            sizeof(xmlNodePtr));
        if (val1->nodeTab == NULL) {
            xmlXPathErrMemory(NULL, "merging nodeset\n");
        goto error;
        }
        memset(val1->nodeTab, 0 ,
           XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        val1->nodeMax = XML_NODESET_DEFAULT;
    } else if (val1->nodeNr == val1->nodeMax) {
        xmlNodePtr *temp;
 
            if (val1->nodeMax >= XPATH_MAX_NODESET_LENGTH) {
                xmlXPathErrMemory(NULL, "merging nodeset hit limit\n");
                goto error;
            }
        temp = (xmlNodePtr *) xmlRealloc(val1->nodeTab, val1->nodeMax * 2 *
                         sizeof(xmlNodePtr));
        if (temp == NULL) {
            xmlXPathErrMemory(NULL, "merging nodeset\n");
        goto error;
        }
        val1->nodeTab = temp;
        val1->nodeMax *= 2;
    }
    if (n2->type == XML_NAMESPACE_DECL) {
        xmlNsPtr ns = (xmlNsPtr) n2;
            xmlNodePtr nsNode = xmlXPathNodeSetDupNs((xmlNodePtr) ns->next, ns);
 
            if (nsNode == NULL)
                goto error;
        val1->nodeTab[val1->nodeNr++] = nsNode;
    } else
        val1->nodeTab[val1->nodeNr++] = n2;
    }
 
    return(val1);
 
error:
    xmlXPathFreeNodeSet(val1);
    return(NULL);
}
 
 
static xmlNodeSetPtr
xmlXPathNodeSetMergeAndClear(xmlNodeSetPtr set1, xmlNodeSetPtr set2)
{
    {
    int i, j, initNbSet1;
    xmlNodePtr n1, n2;
 
    initNbSet1 = set1->nodeNr;
    for (i = 0;i < set2->nodeNr;i++) {
        n2 = set2->nodeTab[i];
        /*
        * Skip duplicates.
        */
        for (j = 0; j < initNbSet1; j++) {
        n1 = set1->nodeTab[j];
        if (n1 == n2) {
            goto skip_node;
        } else if ((n1->type == XML_NAMESPACE_DECL) &&
            (n2->type == XML_NAMESPACE_DECL))
        {
            if ((((xmlNsPtr) n1)->next == ((xmlNsPtr) n2)->next) &&
            (xmlStrEqual(((xmlNsPtr) n1)->prefix,
            ((xmlNsPtr) n2)->prefix)))
            {
            /*
            * Free the namespace node.
            */
            xmlXPathNodeSetFreeNs((xmlNsPtr) n2);
            goto skip_node;
            }
        }
        }
        /*
        * grow the nodeTab if needed
        */
        if (set1->nodeMax == 0) {
        set1->nodeTab = (xmlNodePtr *) xmlMalloc(
            XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        if (set1->nodeTab == NULL) {
            xmlXPathErrMemory(NULL, "merging nodeset\n");
            goto error;
        }
        memset(set1->nodeTab, 0,
            XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        set1->nodeMax = XML_NODESET_DEFAULT;
        } else if (set1->nodeNr >= set1->nodeMax) {
        xmlNodePtr *temp;
 
                if (set1->nodeMax >= XPATH_MAX_NODESET_LENGTH) {
                    xmlXPathErrMemory(NULL, "merging nodeset hit limit\n");
                    goto error;
                }
        temp = (xmlNodePtr *) xmlRealloc(
            set1->nodeTab, set1->nodeMax * 2 * sizeof(xmlNodePtr));
        if (temp == NULL) {
            xmlXPathErrMemory(NULL, "merging nodeset\n");
            goto error;
        }
        set1->nodeTab = temp;
        set1->nodeMax *= 2;
        }
        set1->nodeTab[set1->nodeNr++] = n2;
skip_node:
            set2->nodeTab[i] = NULL;
    }
    }
    set2->nodeNr = 0;
    return(set1);
 
error:
    xmlXPathFreeNodeSet(set1);
    xmlXPathNodeSetClear(set2, 1);
    return(NULL);
}
 
static xmlNodeSetPtr
xmlXPathNodeSetMergeAndClearNoDupls(xmlNodeSetPtr set1, xmlNodeSetPtr set2)
{
    {
    int i;
    xmlNodePtr n2;
 
    for (i = 0;i < set2->nodeNr;i++) {
        n2 = set2->nodeTab[i];
        if (set1->nodeMax == 0) {
        set1->nodeTab = (xmlNodePtr *) xmlMalloc(
            XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        if (set1->nodeTab == NULL) {
            xmlXPathErrMemory(NULL, "merging nodeset\n");
            goto error;
        }
        memset(set1->nodeTab, 0,
            XML_NODESET_DEFAULT * sizeof(xmlNodePtr));
        set1->nodeMax = XML_NODESET_DEFAULT;
        } else if (set1->nodeNr >= set1->nodeMax) {
        xmlNodePtr *temp;
 
                if (set1->nodeMax >= XPATH_MAX_NODESET_LENGTH) {
                    xmlXPathErrMemory(NULL, "merging nodeset hit limit\n");
                    goto error;
                }
        temp = (xmlNodePtr *) xmlRealloc(
            set1->nodeTab, set1->nodeMax * 2 * sizeof(xmlNodePtr));
        if (temp == NULL) {
            xmlXPathErrMemory(NULL, "merging nodeset\n");
            goto error;
        }
        set1->nodeTab = temp;
        set1->nodeMax *= 2;
        }
        set1->nodeTab[set1->nodeNr++] = n2;
            set2->nodeTab[i] = NULL;
    }
    }
    set2->nodeNr = 0;
    return(set1);
 
error:
    xmlXPathFreeNodeSet(set1);
    xmlXPathNodeSetClear(set2, 1);
    return(NULL);
}
 
void
xmlXPathNodeSetDel(xmlNodeSetPtr cur, xmlNodePtr val) {
    int i;
 
    if (cur == NULL) return;
    if (val == NULL) return;
 
    /*
     * find node in nodeTab
     */
    for (i = 0;i < cur->nodeNr;i++)
        if (cur->nodeTab[i] == val) break;
 
    if (i >= cur->nodeNr) { /* not found */
        return;
    }
    if ((cur->nodeTab[i] != NULL) &&
    (cur->nodeTab[i]->type == XML_NAMESPACE_DECL))
    xmlXPathNodeSetFreeNs((xmlNsPtr) cur->nodeTab[i]);
    cur->nodeNr--;
    for (;i < cur->nodeNr;i++)
        cur->nodeTab[i] = cur->nodeTab[i + 1];
    cur->nodeTab[cur->nodeNr] = NULL;
}
 
void
xmlXPathNodeSetRemove(xmlNodeSetPtr cur, int val) {
    if (cur == NULL) return;
    if (val >= cur->nodeNr) return;
    if ((cur->nodeTab[val] != NULL) &&
    (cur->nodeTab[val]->type == XML_NAMESPACE_DECL))
    xmlXPathNodeSetFreeNs((xmlNsPtr) cur->nodeTab[val]);
    cur->nodeNr--;
    for (;val < cur->nodeNr;val++)
        cur->nodeTab[val] = cur->nodeTab[val + 1];
    cur->nodeTab[cur->nodeNr] = NULL;
}
 
void
xmlXPathFreeNodeSet(xmlNodeSetPtr obj) {
    if (obj == NULL) return;
    if (obj->nodeTab != NULL) {
    int i;
 
    /* @@ with_ns to check whether namespace nodes should be looked at @@ */
    for (i = 0;i < obj->nodeNr;i++)
        if ((obj->nodeTab[i] != NULL) &&
        (obj->nodeTab[i]->type == XML_NAMESPACE_DECL))
        xmlXPathNodeSetFreeNs((xmlNsPtr) obj->nodeTab[i]);
    xmlFree(obj->nodeTab);
    }
    xmlFree(obj);
}
 
static void
xmlXPathNodeSetClearFromPos(xmlNodeSetPtr set, int pos, int hasNsNodes)
{
    if ((set == NULL) || (pos >= set->nodeNr))
    return;
    else if ((hasNsNodes)) {
    int i;
    xmlNodePtr node;
 
    for (i = pos; i < set->nodeNr; i++) {
        node = set->nodeTab[i];
        if ((node != NULL) &&
        (node->type == XML_NAMESPACE_DECL))
        xmlXPathNodeSetFreeNs((xmlNsPtr) node);
    }
    }
    set->nodeNr = pos;
}
 
static void
xmlXPathNodeSetClear(xmlNodeSetPtr set, int hasNsNodes)
{
    xmlXPathNodeSetClearFromPos(set, 0, hasNsNodes);
}
 
static void
xmlXPathNodeSetKeepLast(xmlNodeSetPtr set)
{
    int i;
    xmlNodePtr node;
 
    if ((set == NULL) || (set->nodeNr <= 1))
    return;
    for (i = 0; i < set->nodeNr - 1; i++) {
        node = set->nodeTab[i];
        if ((node != NULL) &&
            (node->type == XML_NAMESPACE_DECL))
            xmlXPathNodeSetFreeNs((xmlNsPtr) node);
    }
    set->nodeTab[0] = set->nodeTab[set->nodeNr-1];
    set->nodeNr = 1;
}
 
static void
xmlXPathFreeValueTree(xmlNodeSetPtr obj) {
    int i;
 
    if (obj == NULL) return;
 
    if (obj->nodeTab != NULL) {
    for (i = 0;i < obj->nodeNr;i++) {
        if (obj->nodeTab[i] != NULL) {
        if (obj->nodeTab[i]->type == XML_NAMESPACE_DECL) {
            xmlXPathNodeSetFreeNs((xmlNsPtr) obj->nodeTab[i]);
        } else {
            xmlFreeNodeList(obj->nodeTab[i]);
        }
        }
    }
    xmlFree(obj->nodeTab);
    }
    xmlFree(obj);
}
 
xmlXPathObjectPtr
xmlXPathNewNodeSet(xmlNodePtr val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating nodeset\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathObject));
    ret->type = XPATH_NODESET;
    ret->boolval = 0;
    /* TODO: Check memory error. */
    ret->nodesetval = xmlXPathNodeSetCreate(val);
    /* @@ with_ns to check whether namespace nodes should be looked at @@ */
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathNewValueTree(xmlNodePtr val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating result value tree\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathObject));
    ret->type = XPATH_XSLT_TREE;
    ret->boolval = 1;
    ret->user = (void *) val;
    ret->nodesetval = xmlXPathNodeSetCreate(val);
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathNewNodeSetList(xmlNodeSetPtr val)
{
    xmlXPathObjectPtr ret;
    int i;
 
    if (val == NULL)
        ret = NULL;
    else if (val->nodeTab == NULL)
        ret = xmlXPathNewNodeSet(NULL);
    else {
        ret = xmlXPathNewNodeSet(val->nodeTab[0]);
        if (ret) {
            for (i = 1; i < val->nodeNr; ++i) {
                /* TODO: Propagate memory error. */
                if (xmlXPathNodeSetAddUnique(ret->nodesetval, val->nodeTab[i])
            < 0) break;
        }
    }
    }
 
    return (ret);
}
 
xmlXPathObjectPtr
xmlXPathWrapNodeSet(xmlNodeSetPtr val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating node set object\n");
        xmlXPathFreeNodeSet(val);
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathObject));
    ret->type = XPATH_NODESET;
    ret->nodesetval = val;
    return(ret);
}
 
void
xmlXPathFreeNodeSetList(xmlXPathObjectPtr obj) {
    if (obj == NULL) return;
    xmlFree(obj);
}
 
xmlNodeSetPtr
xmlXPathDifference (xmlNodeSetPtr nodes1, xmlNodeSetPtr nodes2) {
    xmlNodeSetPtr ret;
    int i, l1;
    xmlNodePtr cur;
 
    if (xmlXPathNodeSetIsEmpty(nodes2))
    return(nodes1);
 
    /* TODO: Check memory error. */
    ret = xmlXPathNodeSetCreate(NULL);
    if (xmlXPathNodeSetIsEmpty(nodes1))
    return(ret);
 
    l1 = xmlXPathNodeSetGetLength(nodes1);
 
    for (i = 0; i < l1; i++) {
    cur = xmlXPathNodeSetItem(nodes1, i);
    if (!xmlXPathNodeSetContains(nodes2, cur)) {
            /* TODO: Propagate memory error. */
        if (xmlXPathNodeSetAddUnique(ret, cur) < 0)
            break;
    }
    }
    return(ret);
}
 
xmlNodeSetPtr
xmlXPathIntersection (xmlNodeSetPtr nodes1, xmlNodeSetPtr nodes2) {
    xmlNodeSetPtr ret = xmlXPathNodeSetCreate(NULL);
    int i, l1;
    xmlNodePtr cur;
 
    if (ret == NULL)
        return(ret);
    if (xmlXPathNodeSetIsEmpty(nodes1))
    return(ret);
    if (xmlXPathNodeSetIsEmpty(nodes2))
    return(ret);
 
    l1 = xmlXPathNodeSetGetLength(nodes1);
 
    for (i = 0; i < l1; i++) {
    cur = xmlXPathNodeSetItem(nodes1, i);
    if (xmlXPathNodeSetContains(nodes2, cur)) {
            /* TODO: Propagate memory error. */
        if (xmlXPathNodeSetAddUnique(ret, cur) < 0)
            break;
    }
    }
    return(ret);
}
 
xmlNodeSetPtr
xmlXPathDistinctSorted (xmlNodeSetPtr nodes) {
    xmlNodeSetPtr ret;
    xmlHashTablePtr hash;
    int i, l;
    xmlChar * strval;
    xmlNodePtr cur;
 
    if (xmlXPathNodeSetIsEmpty(nodes))
    return(nodes);
 
    ret = xmlXPathNodeSetCreate(NULL);
    if (ret == NULL)
        return(ret);
    l = xmlXPathNodeSetGetLength(nodes);
    hash = xmlHashCreate (l);
    for (i = 0; i < l; i++) {
    cur = xmlXPathNodeSetItem(nodes, i);
    strval = xmlXPathCastNodeToString(cur);
    if (xmlHashLookup(hash, strval) == NULL) {
        if (xmlHashAddEntry(hash, strval, strval) < 0) {
                xmlFree(strval);
                goto error;
            }
        if (xmlXPathNodeSetAddUnique(ret, cur) < 0)
            goto error;
    } else {
        xmlFree(strval);
    }
    }
    xmlHashFree(hash, xmlHashDefaultDeallocator);
    return(ret);
 
error:
    xmlHashFree(hash, xmlHashDefaultDeallocator);
    xmlXPathFreeNodeSet(ret);
    return(NULL);
}
 
xmlNodeSetPtr
xmlXPathDistinct (xmlNodeSetPtr nodes) {
    if (xmlXPathNodeSetIsEmpty(nodes))
    return(nodes);
 
    xmlXPathNodeSetSort(nodes);
    return(xmlXPathDistinctSorted(nodes));
}
 
int
xmlXPathHasSameNodes (xmlNodeSetPtr nodes1, xmlNodeSetPtr nodes2) {
    int i, l;
    xmlNodePtr cur;
 
    if (xmlXPathNodeSetIsEmpty(nodes1) ||
    xmlXPathNodeSetIsEmpty(nodes2))
    return(0);
 
    l = xmlXPathNodeSetGetLength(nodes1);
    for (i = 0; i < l; i++) {
    cur = xmlXPathNodeSetItem(nodes1, i);
    if (xmlXPathNodeSetContains(nodes2, cur))
        return(1);
    }
    return(0);
}
 
xmlNodeSetPtr
xmlXPathNodeLeadingSorted (xmlNodeSetPtr nodes, xmlNodePtr node) {
    int i, l;
    xmlNodePtr cur;
    xmlNodeSetPtr ret;
 
    if (node == NULL)
    return(nodes);
 
    ret = xmlXPathNodeSetCreate(NULL);
    if (ret == NULL)
        return(ret);
    if (xmlXPathNodeSetIsEmpty(nodes) ||
    (!xmlXPathNodeSetContains(nodes, node)))
    return(ret);
 
    l = xmlXPathNodeSetGetLength(nodes);
    for (i = 0; i < l; i++) {
    cur = xmlXPathNodeSetItem(nodes, i);
    if (cur == node)
        break;
        /* TODO: Propagate memory error. */
    if (xmlXPathNodeSetAddUnique(ret, cur) < 0)
        break;
    }
    return(ret);
}
 
xmlNodeSetPtr
xmlXPathNodeLeading (xmlNodeSetPtr nodes, xmlNodePtr node) {
    xmlXPathNodeSetSort(nodes);
    return(xmlXPathNodeLeadingSorted(nodes, node));
}
 
xmlNodeSetPtr
xmlXPathLeadingSorted (xmlNodeSetPtr nodes1, xmlNodeSetPtr nodes2) {
    if (xmlXPathNodeSetIsEmpty(nodes2))
    return(nodes1);
    return(xmlXPathNodeLeadingSorted(nodes1,
                     xmlXPathNodeSetItem(nodes2, 1)));
}
 
xmlNodeSetPtr
xmlXPathLeading (xmlNodeSetPtr nodes1, xmlNodeSetPtr nodes2) {
    if (xmlXPathNodeSetIsEmpty(nodes2))
    return(nodes1);
    if (xmlXPathNodeSetIsEmpty(nodes1))
    return(xmlXPathNodeSetCreate(NULL));
    xmlXPathNodeSetSort(nodes1);
    xmlXPathNodeSetSort(nodes2);
    return(xmlXPathNodeLeadingSorted(nodes1,
                     xmlXPathNodeSetItem(nodes2, 1)));
}
 
xmlNodeSetPtr
xmlXPathNodeTrailingSorted (xmlNodeSetPtr nodes, xmlNodePtr node) {
    int i, l;
    xmlNodePtr cur;
    xmlNodeSetPtr ret;
 
    if (node == NULL)
    return(nodes);
 
    ret = xmlXPathNodeSetCreate(NULL);
    if (ret == NULL)
        return(ret);
    if (xmlXPathNodeSetIsEmpty(nodes) ||
    (!xmlXPathNodeSetContains(nodes, node)))
    return(ret);
 
    l = xmlXPathNodeSetGetLength(nodes);
    for (i = l - 1; i >= 0; i--) {
    cur = xmlXPathNodeSetItem(nodes, i);
    if (cur == node)
        break;
        /* TODO: Propagate memory error. */
    if (xmlXPathNodeSetAddUnique(ret, cur) < 0)
        break;
    }
    xmlXPathNodeSetSort(ret);   /* bug 413451 */
    return(ret);
}
 
xmlNodeSetPtr
xmlXPathNodeTrailing (xmlNodeSetPtr nodes, xmlNodePtr node) {
    xmlXPathNodeSetSort(nodes);
    return(xmlXPathNodeTrailingSorted(nodes, node));
}
 
xmlNodeSetPtr
xmlXPathTrailingSorted (xmlNodeSetPtr nodes1, xmlNodeSetPtr nodes2) {
    if (xmlXPathNodeSetIsEmpty(nodes2))
    return(nodes1);
    return(xmlXPathNodeTrailingSorted(nodes1,
                      xmlXPathNodeSetItem(nodes2, 0)));
}
 
xmlNodeSetPtr
xmlXPathTrailing (xmlNodeSetPtr nodes1, xmlNodeSetPtr nodes2) {
    if (xmlXPathNodeSetIsEmpty(nodes2))
    return(nodes1);
    if (xmlXPathNodeSetIsEmpty(nodes1))
    return(xmlXPathNodeSetCreate(NULL));
    xmlXPathNodeSetSort(nodes1);
    xmlXPathNodeSetSort(nodes2);
    return(xmlXPathNodeTrailingSorted(nodes1,
                      xmlXPathNodeSetItem(nodes2, 0)));
}
 
/************************************************************************
 *                                  *
 *      Routines to handle extra functions          *
 *                                  *
 ************************************************************************/
 
int
xmlXPathRegisterFunc(xmlXPathContextPtr ctxt, const xmlChar *name,
             xmlXPathFunction f) {
    return(xmlXPathRegisterFuncNS(ctxt, name, NULL, f));
}
 
int
xmlXPathRegisterFuncNS(xmlXPathContextPtr ctxt, const xmlChar *name,
               const xmlChar *ns_uri, xmlXPathFunction f) {
    if (ctxt == NULL)
    return(-1);
    if (name == NULL)
    return(-1);
 
    if (ctxt->funcHash == NULL)
    ctxt->funcHash = xmlHashCreate(0);
    if (ctxt->funcHash == NULL)
    return(-1);
    if (f == NULL)
        return(xmlHashRemoveEntry2(ctxt->funcHash, name, ns_uri, NULL));
XML_IGNORE_FPTR_CAST_WARNINGS
    return(xmlHashAddEntry2(ctxt->funcHash, name, ns_uri, (void *) f));
XML_POP_WARNINGS
}
 
void
xmlXPathRegisterFuncLookup (xmlXPathContextPtr ctxt,
                xmlXPathFuncLookupFunc f,
                void *funcCtxt) {
    if (ctxt == NULL)
    return;
    ctxt->funcLookupFunc = f;
    ctxt->funcLookupData = funcCtxt;
}
 
xmlXPathFunction
xmlXPathFunctionLookup(xmlXPathContextPtr ctxt, const xmlChar *name) {
    if (ctxt == NULL)
    return (NULL);
 
    if (ctxt->funcLookupFunc != NULL) {
    xmlXPathFunction ret;
    xmlXPathFuncLookupFunc f;
 
    f = ctxt->funcLookupFunc;
    ret = f(ctxt->funcLookupData, name, NULL);
    if (ret != NULL)
        return(ret);
    }
    return(xmlXPathFunctionLookupNS(ctxt, name, NULL));
}
 
xmlXPathFunction
xmlXPathFunctionLookupNS(xmlXPathContextPtr ctxt, const xmlChar *name,
             const xmlChar *ns_uri) {
    xmlXPathFunction ret;
 
    if (ctxt == NULL)
    return(NULL);
    if (name == NULL)
    return(NULL);
 
    if (ctxt->funcLookupFunc != NULL) {
    xmlXPathFuncLookupFunc f;
 
    f = ctxt->funcLookupFunc;
    ret = f(ctxt->funcLookupData, name, ns_uri);
    if (ret != NULL)
        return(ret);
    }
 
    if (ctxt->funcHash == NULL)
    return(NULL);
 
XML_IGNORE_FPTR_CAST_WARNINGS
    ret = (xmlXPathFunction) xmlHashLookup2(ctxt->funcHash, name, ns_uri);
XML_POP_WARNINGS
    return(ret);
}
 
void
xmlXPathRegisteredFuncsCleanup(xmlXPathContextPtr ctxt) {
    if (ctxt == NULL)
    return;
 
    xmlHashFree(ctxt->funcHash, NULL);
    ctxt->funcHash = NULL;
}
 
/************************************************************************
 *                                  *
 *          Routines to handle Variables            *
 *                                  *
 ************************************************************************/
 
int
xmlXPathRegisterVariable(xmlXPathContextPtr ctxt, const xmlChar *name,
             xmlXPathObjectPtr value) {
    return(xmlXPathRegisterVariableNS(ctxt, name, NULL, value));
}
 
int
xmlXPathRegisterVariableNS(xmlXPathContextPtr ctxt, const xmlChar *name,
               const xmlChar *ns_uri,
               xmlXPathObjectPtr value) {
    if (ctxt == NULL)
    return(-1);
    if (name == NULL)
    return(-1);
 
    if (ctxt->varHash == NULL)
    ctxt->varHash = xmlHashCreate(0);
    if (ctxt->varHash == NULL)
    return(-1);
    if (value == NULL)
        return(xmlHashRemoveEntry2(ctxt->varHash, name, ns_uri,
                               xmlXPathFreeObjectEntry));
    return(xmlHashUpdateEntry2(ctxt->varHash, name, ns_uri,
                   (void *) value, xmlXPathFreeObjectEntry));
}
 
void
xmlXPathRegisterVariableLookup(xmlXPathContextPtr ctxt,
     xmlXPathVariableLookupFunc f, void *data) {
    if (ctxt == NULL)
    return;
    ctxt->varLookupFunc = f;
    ctxt->varLookupData = data;
}
 
xmlXPathObjectPtr
xmlXPathVariableLookup(xmlXPathContextPtr ctxt, const xmlChar *name) {
    if (ctxt == NULL)
    return(NULL);
 
    if (ctxt->varLookupFunc != NULL) {
    xmlXPathObjectPtr ret;
 
    ret = ((xmlXPathVariableLookupFunc)ctxt->varLookupFunc)
            (ctxt->varLookupData, name, NULL);
    return(ret);
    }
    return(xmlXPathVariableLookupNS(ctxt, name, NULL));
}
 
xmlXPathObjectPtr
xmlXPathVariableLookupNS(xmlXPathContextPtr ctxt, const xmlChar *name,
             const xmlChar *ns_uri) {
    if (ctxt == NULL)
    return(NULL);
 
    if (ctxt->varLookupFunc != NULL) {
    xmlXPathObjectPtr ret;
 
    ret = ((xmlXPathVariableLookupFunc)ctxt->varLookupFunc)
            (ctxt->varLookupData, name, ns_uri);
    if (ret != NULL) return(ret);
    }
 
    if (ctxt->varHash == NULL)
    return(NULL);
    if (name == NULL)
    return(NULL);
 
    return(xmlXPathCacheObjectCopy(ctxt, (xmlXPathObjectPtr)
        xmlHashLookup2(ctxt->varHash, name, ns_uri)));
}
 
void
xmlXPathRegisteredVariablesCleanup(xmlXPathContextPtr ctxt) {
    if (ctxt == NULL)
    return;
 
    xmlHashFree(ctxt->varHash, xmlXPathFreeObjectEntry);
    ctxt->varHash = NULL;
}
 
int
xmlXPathRegisterNs(xmlXPathContextPtr ctxt, const xmlChar *prefix,
               const xmlChar *ns_uri) {
    xmlChar *copy;
 
    if (ctxt == NULL)
    return(-1);
    if (prefix == NULL)
    return(-1);
    if (prefix[0] == 0)
    return(-1);
 
    if (ctxt->nsHash == NULL)
    ctxt->nsHash = xmlHashCreate(10);
    if (ctxt->nsHash == NULL)
    return(-1);
    if (ns_uri == NULL)
        return(xmlHashRemoveEntry(ctxt->nsHash, prefix,
                              xmlHashDefaultDeallocator));
 
    copy = xmlStrdup(ns_uri);
    if (copy == NULL)
        return(-1);
    if (xmlHashUpdateEntry(ctxt->nsHash, prefix, copy,
                           xmlHashDefaultDeallocator) < 0) {
        xmlFree(copy);
        return(-1);
    }
 
    return(0);
}
 
const xmlChar *
xmlXPathNsLookup(xmlXPathContextPtr ctxt, const xmlChar *prefix) {
    if (ctxt == NULL)
    return(NULL);
    if (prefix == NULL)
    return(NULL);
 
#ifdef XML_XML_NAMESPACE
    if (xmlStrEqual(prefix, (const xmlChar *) "xml"))
    return(XML_XML_NAMESPACE);
#endif
 
    if (ctxt->namespaces != NULL) {
    int i;
 
    for (i = 0;i < ctxt->nsNr;i++) {
        if ((ctxt->namespaces[i] != NULL) &&
        (xmlStrEqual(ctxt->namespaces[i]->prefix, prefix)))
        return(ctxt->namespaces[i]->href);
    }
    }
 
    return((const xmlChar *) xmlHashLookup(ctxt->nsHash, prefix));
}
 
void
xmlXPathRegisteredNsCleanup(xmlXPathContextPtr ctxt) {
    if (ctxt == NULL)
    return;
 
    xmlHashFree(ctxt->nsHash, xmlHashDefaultDeallocator);
    ctxt->nsHash = NULL;
}
 
/************************************************************************
 *                                  *
 *          Routines to handle Values           *
 *                                  *
 ************************************************************************/
 
/* Allocations are terrible, one needs to optimize all this !!! */
 
xmlXPathObjectPtr
xmlXPathNewFloat(double val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating float object\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathObject));
    ret->type = XPATH_NUMBER;
    ret->floatval = val;
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathNewBoolean(int val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating boolean object\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathObject));
    ret->type = XPATH_BOOLEAN;
    ret->boolval = (val != 0);
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathNewString(const xmlChar *val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating string object\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathObject));
    ret->type = XPATH_STRING;
    if (val == NULL)
        val = BAD_CAST "";
    ret->stringval = xmlStrdup(val);
    if (ret->stringval == NULL) {
        xmlFree(ret);
        return(NULL);
    }
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathWrapString (xmlChar *val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating string object\n");
        xmlFree(val);
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathObject));
    ret->type = XPATH_STRING;
    ret->stringval = val;
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathNewCString(const char *val) {
    return(xmlXPathNewString(BAD_CAST val));
}
 
xmlXPathObjectPtr
xmlXPathWrapCString (char * val) {
    return(xmlXPathWrapString((xmlChar *)(val)));
}
 
xmlXPathObjectPtr
xmlXPathWrapExternal (void *val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating user object\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathObject));
    ret->type = XPATH_USERS;
    ret->user = val;
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathObjectCopy(xmlXPathObjectPtr val) {
    xmlXPathObjectPtr ret;
 
    if (val == NULL)
    return(NULL);
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "copying object\n");
    return(NULL);
    }
    memcpy(ret, val , sizeof(xmlXPathObject));
    switch (val->type) {
    case XPATH_BOOLEAN:
    case XPATH_NUMBER:
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_POINT:
    case XPATH_RANGE:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
        break;
    case XPATH_STRING:
        ret->stringval = xmlStrdup(val->stringval);
            if (ret->stringval == NULL) {
                xmlFree(ret);
                return(NULL);
            }
        break;
    case XPATH_XSLT_TREE:
#if 0
/*
  Removed 11 July 2004 - the current handling of xslt tmpRVT nodes means that
  this previous handling is no longer correct, and can cause some serious
  problems (ref. bug 145547)
*/
        if ((val->nodesetval != NULL) &&
        (val->nodesetval->nodeTab != NULL)) {
        xmlNodePtr cur, tmp;
        xmlDocPtr top;
 
        ret->boolval = 1;
        top =  xmlNewDoc(NULL);
        top->name = (char *)
            xmlStrdup(val->nodesetval->nodeTab[0]->name);
        ret->user = top;
        if (top != NULL) {
            top->doc = top;
            cur = val->nodesetval->nodeTab[0]->children;
            while (cur != NULL) {
            tmp = xmlDocCopyNode(cur, top, 1);
            xmlAddChild((xmlNodePtr) top, tmp);
            cur = cur->next;
            }
        }
 
        ret->nodesetval = xmlXPathNodeSetCreate((xmlNodePtr) top);
        } else
        ret->nodesetval = xmlXPathNodeSetCreate(NULL);
        /* Deallocate the copied tree value */
        break;
#endif
    case XPATH_NODESET:
            /* TODO: Check memory error. */
        ret->nodesetval = xmlXPathNodeSetMerge(NULL, val->nodesetval);
        /* Do not deallocate the copied tree value */
        ret->boolval = 0;
        break;
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_LOCATIONSET:
    {
        xmlLocationSetPtr loc = val->user;
        ret->user = (void *) xmlXPtrLocationSetMerge(NULL, loc);
        break;
    }
#endif
        case XPATH_USERS:
        ret->user = val->user;
        break;
        case XPATH_UNDEFINED:
        xmlGenericError(xmlGenericErrorContext,
            "xmlXPathObjectCopy: unsupported type %d\n",
            val->type);
        break;
    }
    return(ret);
}
 
void
xmlXPathFreeObject(xmlXPathObjectPtr obj) {
    if (obj == NULL) return;
    if ((obj->type == XPATH_NODESET) || (obj->type == XPATH_XSLT_TREE)) {
    if (obj->boolval) {
#if 0
        if (obj->user != NULL) {
                xmlXPathFreeNodeSet(obj->nodesetval);
        xmlFreeNodeList((xmlNodePtr) obj->user);
        } else
#endif
        obj->type = XPATH_XSLT_TREE; /* TODO: Just for debugging. */
        if (obj->nodesetval != NULL)
        xmlXPathFreeValueTree(obj->nodesetval);
    } else {
        if (obj->nodesetval != NULL)
        xmlXPathFreeNodeSet(obj->nodesetval);
    }
#ifdef LIBXML_XPTR_LOCS_ENABLED
    } else if (obj->type == XPATH_LOCATIONSET) {
    if (obj->user != NULL)
        xmlXPtrFreeLocationSet(obj->user);
#endif
    } else if (obj->type == XPATH_STRING) {
    if (obj->stringval != NULL)
        xmlFree(obj->stringval);
    }
    xmlFree(obj);
}
 
static void
xmlXPathFreeObjectEntry(void *obj, const xmlChar *name ATTRIBUTE_UNUSED) {
    xmlXPathFreeObject((xmlXPathObjectPtr) obj);
}
 
static void
xmlXPathReleaseObject(xmlXPathContextPtr ctxt, xmlXPathObjectPtr obj)
{
#define XP_CACHE_ADD(sl, o) if (sl == NULL) { \
    sl = xmlPointerListCreate(10); if (sl == NULL) goto free_obj; } \
    if (xmlPointerListAddSize(sl, obj, 0) == -1) goto free_obj;
 
#define XP_CACHE_WANTS(sl, n) ((sl == NULL) || ((sl)->number < n))
 
    if (obj == NULL)
    return;
    if ((ctxt == NULL) || (ctxt->cache == NULL)) {
     xmlXPathFreeObject(obj);
    } else {
    xmlXPathContextCachePtr cache =
        (xmlXPathContextCachePtr) ctxt->cache;
 
    switch (obj->type) {
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
        if (obj->nodesetval != NULL) {
            if (obj->boolval) {
            /*
            * It looks like the @boolval is used for
            * evaluation if this an XSLT Result Tree Fragment.
            * TODO: Check if this assumption is correct.
            */
            obj->type = XPATH_XSLT_TREE; /* just for debugging */
            xmlXPathFreeValueTree(obj->nodesetval);
            obj->nodesetval = NULL;
            } else if ((obj->nodesetval->nodeMax <= 40) &&
            (XP_CACHE_WANTS(cache->nodesetObjs,
                    cache->maxNodeset)))
            {
            XP_CACHE_ADD(cache->nodesetObjs, obj);
            goto obj_cached;
            } else {
            xmlXPathFreeNodeSet(obj->nodesetval);
            obj->nodesetval = NULL;
            }
        }
        break;
        case XPATH_STRING:
        if (obj->stringval != NULL)
            xmlFree(obj->stringval);
 
        if (XP_CACHE_WANTS(cache->stringObjs, cache->maxString)) {
            XP_CACHE_ADD(cache->stringObjs, obj);
            goto obj_cached;
        }
        break;
        case XPATH_BOOLEAN:
        if (XP_CACHE_WANTS(cache->booleanObjs, cache->maxBoolean)) {
            XP_CACHE_ADD(cache->booleanObjs, obj);
            goto obj_cached;
        }
        break;
        case XPATH_NUMBER:
        if (XP_CACHE_WANTS(cache->numberObjs, cache->maxNumber)) {
            XP_CACHE_ADD(cache->numberObjs, obj);
            goto obj_cached;
        }
        break;
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_LOCATIONSET:
        if (obj->user != NULL) {
            xmlXPtrFreeLocationSet(obj->user);
        }
        goto free_obj;
#endif
        default:
        goto free_obj;
    }
 
    /*
    * Fallback to adding to the misc-objects slot.
    */
    if (XP_CACHE_WANTS(cache->miscObjs, cache->maxMisc)) {
        XP_CACHE_ADD(cache->miscObjs, obj);
    } else
        goto free_obj;
 
obj_cached:
    if (obj->nodesetval != NULL) {
        xmlNodeSetPtr tmpset = obj->nodesetval;
 
        /*
        * TODO: Due to those nasty ns-nodes, we need to traverse
        *  the list and free the ns-nodes.
        * URGENT TODO: Check if it's actually slowing things down.
        *  Maybe we shouldn't try to preserve the list.
        */
        if (tmpset->nodeNr > 1) {
        int i;
        xmlNodePtr node;
 
        for (i = 0; i < tmpset->nodeNr; i++) {
            node = tmpset->nodeTab[i];
            if ((node != NULL) &&
            (node->type == XML_NAMESPACE_DECL))
            {
            xmlXPathNodeSetFreeNs((xmlNsPtr) node);
            }
        }
        } else if (tmpset->nodeNr == 1) {
        if ((tmpset->nodeTab[0] != NULL) &&
            (tmpset->nodeTab[0]->type == XML_NAMESPACE_DECL))
            xmlXPathNodeSetFreeNs((xmlNsPtr) tmpset->nodeTab[0]);
        }
        tmpset->nodeNr = 0;
        memset(obj, 0, sizeof(xmlXPathObject));
        obj->nodesetval = tmpset;
    } else
        memset(obj, 0, sizeof(xmlXPathObject));
 
    return;
 
free_obj:
    /*
    * Cache is full; free the object.
    */
    if (obj->nodesetval != NULL)
        xmlXPathFreeNodeSet(obj->nodesetval);
    xmlFree(obj);
    }
    return;
}
 
 
/************************************************************************
 *                                  *
 *          Type Casting Routines               *
 *                                  *
 ************************************************************************/
 
xmlChar *
xmlXPathCastBooleanToString (int val) {
    xmlChar *ret;
    if (val)
    ret = xmlStrdup((const xmlChar *) "true");
    else
    ret = xmlStrdup((const xmlChar *) "false");
    return(ret);
}
 
xmlChar *
xmlXPathCastNumberToString (double val) {
    xmlChar *ret;
    switch (xmlXPathIsInf(val)) {
    case 1:
    ret = xmlStrdup((const xmlChar *) "Infinity");
    break;
    case -1:
    ret = xmlStrdup((const xmlChar *) "-Infinity");
    break;
    default:
    if (xmlXPathIsNaN(val)) {
        ret = xmlStrdup((const xmlChar *) "NaN");
    } else if (val == 0) {
            /* Omit sign for negative zero. */
        ret = xmlStrdup((const xmlChar *) "0");
    } else {
        /* could be improved */
        char buf[100];
        xmlXPathFormatNumber(val, buf, 99);
        buf[99] = 0;
        ret = xmlStrdup((const xmlChar *) buf);
    }
    }
    return(ret);
}
 
xmlChar *
xmlXPathCastNodeToString (xmlNodePtr node) {
xmlChar *ret;
    if ((ret = xmlNodeGetContent(node)) == NULL)
    ret = xmlStrdup((const xmlChar *) "");
    return(ret);
}
 
xmlChar *
xmlXPathCastNodeSetToString (xmlNodeSetPtr ns) {
    if ((ns == NULL) || (ns->nodeNr == 0) || (ns->nodeTab == NULL))
    return(xmlStrdup((const xmlChar *) ""));
 
    if (ns->nodeNr > 1)
    xmlXPathNodeSetSort(ns);
    return(xmlXPathCastNodeToString(ns->nodeTab[0]));
}
 
xmlChar *
xmlXPathCastToString(xmlXPathObjectPtr val) {
    xmlChar *ret = NULL;
 
    if (val == NULL)
    return(xmlStrdup((const xmlChar *) ""));
    switch (val->type) {
    case XPATH_UNDEFINED:
        ret = xmlStrdup((const xmlChar *) "");
        break;
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
        ret = xmlXPathCastNodeSetToString(val->nodesetval);
        break;
    case XPATH_STRING:
        return(xmlStrdup(val->stringval));
        case XPATH_BOOLEAN:
        ret = xmlXPathCastBooleanToString(val->boolval);
        break;
    case XPATH_NUMBER: {
        ret = xmlXPathCastNumberToString(val->floatval);
        break;
    }
    case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_POINT:
    case XPATH_RANGE:
    case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
        TODO
        ret = xmlStrdup((const xmlChar *) "");
        break;
    }
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathConvertString(xmlXPathObjectPtr val) {
    xmlChar *res = NULL;
 
    if (val == NULL)
    return(xmlXPathNewCString(""));
 
    switch (val->type) {
    case XPATH_UNDEFINED:
    break;
    case XPATH_NODESET:
    case XPATH_XSLT_TREE:
    res = xmlXPathCastNodeSetToString(val->nodesetval);
    break;
    case XPATH_STRING:
    return(val);
    case XPATH_BOOLEAN:
    res = xmlXPathCastBooleanToString(val->boolval);
    break;
    case XPATH_NUMBER:
    res = xmlXPathCastNumberToString(val->floatval);
    break;
    case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_POINT:
    case XPATH_RANGE:
    case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
    TODO;
    break;
    }
    xmlXPathFreeObject(val);
    if (res == NULL)
    return(xmlXPathNewCString(""));
    return(xmlXPathWrapString(res));
}
 
double
xmlXPathCastBooleanToNumber(int val) {
    if (val)
    return(1.0);
    return(0.0);
}
 
double
xmlXPathCastStringToNumber(const xmlChar * val) {
    return(xmlXPathStringEvalNumber(val));
}
 
double
xmlXPathCastNodeToNumber (xmlNodePtr node) {
    xmlChar *strval;
    double ret;
 
    if (node == NULL)
    return(xmlXPathNAN);
    strval = xmlXPathCastNodeToString(node);
    if (strval == NULL)
    return(xmlXPathNAN);
    ret = xmlXPathCastStringToNumber(strval);
    xmlFree(strval);
 
    return(ret);
}
 
double
xmlXPathCastNodeSetToNumber (xmlNodeSetPtr ns) {
    xmlChar *str;
    double ret;
 
    if (ns == NULL)
    return(xmlXPathNAN);
    str = xmlXPathCastNodeSetToString(ns);
    ret = xmlXPathCastStringToNumber(str);
    xmlFree(str);
    return(ret);
}
 
double
xmlXPathCastToNumber(xmlXPathObjectPtr val) {
    double ret = 0.0;
 
    if (val == NULL)
    return(xmlXPathNAN);
    switch (val->type) {
    case XPATH_UNDEFINED:
    ret = xmlXPathNAN;
    break;
    case XPATH_NODESET:
    case XPATH_XSLT_TREE:
    ret = xmlXPathCastNodeSetToNumber(val->nodesetval);
    break;
    case XPATH_STRING:
    ret = xmlXPathCastStringToNumber(val->stringval);
    break;
    case XPATH_NUMBER:
    ret = val->floatval;
    break;
    case XPATH_BOOLEAN:
    ret = xmlXPathCastBooleanToNumber(val->boolval);
    break;
    case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_POINT:
    case XPATH_RANGE:
    case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
    TODO;
    ret = xmlXPathNAN;
    break;
    }
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPathConvertNumber(xmlXPathObjectPtr val) {
    xmlXPathObjectPtr ret;
 
    if (val == NULL)
    return(xmlXPathNewFloat(0.0));
    if (val->type == XPATH_NUMBER)
    return(val);
    ret = xmlXPathNewFloat(xmlXPathCastToNumber(val));
    xmlXPathFreeObject(val);
    return(ret);
}
 
int
xmlXPathCastNumberToBoolean (double val) {
     if (xmlXPathIsNaN(val) || (val == 0.0))
     return(0);
     return(1);
}
 
int
xmlXPathCastStringToBoolean (const xmlChar *val) {
    if ((val == NULL) || (xmlStrlen(val) == 0))
    return(0);
    return(1);
}
 
int
xmlXPathCastNodeSetToBoolean (xmlNodeSetPtr ns) {
    if ((ns == NULL) || (ns->nodeNr == 0))
    return(0);
    return(1);
}
 
int
xmlXPathCastToBoolean (xmlXPathObjectPtr val) {
    int ret = 0;
 
    if (val == NULL)
    return(0);
    switch (val->type) {
    case XPATH_UNDEFINED:
    ret = 0;
    break;
    case XPATH_NODESET:
    case XPATH_XSLT_TREE:
    ret = xmlXPathCastNodeSetToBoolean(val->nodesetval);
    break;
    case XPATH_STRING:
    ret = xmlXPathCastStringToBoolean(val->stringval);
    break;
    case XPATH_NUMBER:
    ret = xmlXPathCastNumberToBoolean(val->floatval);
    break;
    case XPATH_BOOLEAN:
    ret = val->boolval;
    break;
    case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_POINT:
    case XPATH_RANGE:
    case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
    TODO;
    ret = 0;
    break;
    }
    return(ret);
}
 
 
xmlXPathObjectPtr
xmlXPathConvertBoolean(xmlXPathObjectPtr val) {
    xmlXPathObjectPtr ret;
 
    if (val == NULL)
    return(xmlXPathNewBoolean(0));
    if (val->type == XPATH_BOOLEAN)
    return(val);
    ret = xmlXPathNewBoolean(xmlXPathCastToBoolean(val));
    xmlXPathFreeObject(val);
    return(ret);
}
 
/************************************************************************
 *                                  *
 *      Routines to handle XPath contexts           *
 *                                  *
 ************************************************************************/
 
xmlXPathContextPtr
xmlXPathNewContext(xmlDocPtr doc) {
    xmlXPathContextPtr ret;
 
    ret = (xmlXPathContextPtr) xmlMalloc(sizeof(xmlXPathContext));
    if (ret == NULL) {
        xmlXPathErrMemory(NULL, "creating context\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathContext));
    ret->doc = doc;
    ret->node = NULL;
 
    ret->varHash = NULL;
 
    ret->nb_types = 0;
    ret->max_types = 0;
    ret->types = NULL;
 
    ret->funcHash = xmlHashCreate(0);
 
    ret->nb_axis = 0;
    ret->max_axis = 0;
    ret->axis = NULL;
 
    ret->nsHash = NULL;
    ret->user = NULL;
 
    ret->contextSize = -1;
    ret->proximityPosition = -1;
 
#ifdef XP_DEFAULT_CACHE_ON
    if (xmlXPathContextSetCache(ret, 1, -1, 0) == -1) {
    xmlXPathFreeContext(ret);
    return(NULL);
    }
#endif
 
    xmlXPathRegisterAllFunctions(ret);
 
    return(ret);
}
 
void
xmlXPathFreeContext(xmlXPathContextPtr ctxt) {
    if (ctxt == NULL) return;
 
    if (ctxt->cache != NULL)
    xmlXPathFreeCache((xmlXPathContextCachePtr) ctxt->cache);
    xmlXPathRegisteredNsCleanup(ctxt);
    xmlXPathRegisteredFuncsCleanup(ctxt);
    xmlXPathRegisteredVariablesCleanup(ctxt);
    xmlResetError(&ctxt->lastError);
    xmlFree(ctxt);
}
 
/************************************************************************
 *                                  *
 *      Routines to handle XPath parser contexts        *
 *                                  *
 ************************************************************************/
 
#define CHECK_CTXT(ctxt)                        \
    if (ctxt == NULL) {                     \
    __xmlRaiseError(NULL, NULL, NULL,               \
        NULL, NULL, XML_FROM_XPATH,             \
        XML_ERR_INTERNAL_ERROR, XML_ERR_FATAL,          \
        __FILE__, __LINE__,                 \
        NULL, NULL, NULL, 0, 0,                 \
        "NULL context pointer\n");              \
    return(NULL);                           \
    }                                   \
 
#define CHECK_CTXT_NEG(ctxt)                        \
    if (ctxt == NULL) {                     \
    __xmlRaiseError(NULL, NULL, NULL,               \
        NULL, NULL, XML_FROM_XPATH,             \
        XML_ERR_INTERNAL_ERROR, XML_ERR_FATAL,          \
        __FILE__, __LINE__,                 \
        NULL, NULL, NULL, 0, 0,                 \
        "NULL context pointer\n");              \
    return(-1);                         \
    }                                   \
 
 
#define CHECK_CONTEXT(ctxt)                     \
    if ((ctxt == NULL) || (ctxt->doc == NULL) ||            \
        (ctxt->doc->children == NULL)) {                \
    xmlXPatherror(ctxt, __FILE__, __LINE__, XPATH_INVALID_CTXT);    \
    return(NULL);                           \
    }
 
 
xmlXPathParserContextPtr
xmlXPathNewParserContext(const xmlChar *str, xmlXPathContextPtr ctxt) {
    xmlXPathParserContextPtr ret;
 
    ret = (xmlXPathParserContextPtr) xmlMalloc(sizeof(xmlXPathParserContext));
    if (ret == NULL) {
        xmlXPathErrMemory(ctxt, "creating parser context\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathParserContext));
    ret->cur = ret->base = str;
    ret->context = ctxt;
 
    ret->comp = xmlXPathNewCompExpr();
    if (ret->comp == NULL) {
    xmlFree(ret->valueTab);
    xmlFree(ret);
    return(NULL);
    }
    if ((ctxt != NULL) && (ctxt->dict != NULL)) {
        ret->comp->dict = ctxt->dict;
    xmlDictReference(ret->comp->dict);
    }
 
    return(ret);
}
 
static xmlXPathParserContextPtr
xmlXPathCompParserContext(xmlXPathCompExprPtr comp, xmlXPathContextPtr ctxt) {
    xmlXPathParserContextPtr ret;
 
    ret = (xmlXPathParserContextPtr) xmlMalloc(sizeof(xmlXPathParserContext));
    if (ret == NULL) {
        xmlXPathErrMemory(ctxt, "creating evaluation context\n");
    return(NULL);
    }
    memset(ret, 0 , sizeof(xmlXPathParserContext));
 
    /* Allocate the value stack */
    ret->valueTab = (xmlXPathObjectPtr *)
                     xmlMalloc(10 * sizeof(xmlXPathObjectPtr));
    if (ret->valueTab == NULL) {
    xmlFree(ret);
    xmlXPathErrMemory(ctxt, "creating evaluation context\n");
    return(NULL);
    }
    ret->valueNr = 0;
    ret->valueMax = 10;
    ret->value = NULL;
 
    ret->context = ctxt;
    ret->comp = comp;
 
    return(ret);
}
 
void
xmlXPathFreeParserContext(xmlXPathParserContextPtr ctxt) {
    int i;
 
    if (ctxt->valueTab != NULL) {
        for (i = 0; i < ctxt->valueNr; i++) {
            if (ctxt->context)
                xmlXPathReleaseObject(ctxt->context, ctxt->valueTab[i]);
            else
                xmlXPathFreeObject(ctxt->valueTab[i]);
        }
        xmlFree(ctxt->valueTab);
    }
    if (ctxt->comp != NULL) {
#ifdef XPATH_STREAMING
    if (ctxt->comp->stream != NULL) {
        xmlFreePatternList(ctxt->comp->stream);
        ctxt->comp->stream = NULL;
    }
#endif
    xmlXPathFreeCompExpr(ctxt->comp);
    }
    xmlFree(ctxt);
}
 
/************************************************************************
 *                                  *
 *      The implicit core function library          *
 *                                  *
 ************************************************************************/
 
static unsigned int
xmlXPathNodeValHash(xmlNodePtr node) {
    int len = 2;
    const xmlChar * string = NULL;
    xmlNodePtr tmp = NULL;
    unsigned int ret = 0;
 
    if (node == NULL)
    return(0);
 
    if (node->type == XML_DOCUMENT_NODE) {
    tmp = xmlDocGetRootElement((xmlDocPtr) node);
    if (tmp == NULL)
        node = node->children;
    else
        node = tmp;
 
    if (node == NULL)
        return(0);
    }
 
    switch (node->type) {
    case XML_COMMENT_NODE:
    case XML_PI_NODE:
    case XML_CDATA_SECTION_NODE:
    case XML_TEXT_NODE:
        string = node->content;
        if (string == NULL)
        return(0);
        if (string[0] == 0)
        return(0);
        return(string[0] + (string[1] << 8));
    case XML_NAMESPACE_DECL:
        string = ((xmlNsPtr)node)->href;
        if (string == NULL)
        return(0);
        if (string[0] == 0)
        return(0);
        return(string[0] + (string[1] << 8));
    case XML_ATTRIBUTE_NODE:
        tmp = ((xmlAttrPtr) node)->children;
        break;
    case XML_ELEMENT_NODE:
        tmp = node->children;
        break;
    default:
        return(0);
    }
    while (tmp != NULL) {
    switch (tmp->type) {
        case XML_CDATA_SECTION_NODE:
        case XML_TEXT_NODE:
        string = tmp->content;
        break;
        default:
                string = NULL;
        break;
    }
    if ((string != NULL) && (string[0] != 0)) {
        if (len == 1) {
        return(ret + (string[0] << 8));
        }
        if (string[1] == 0) {
        len = 1;
        ret = string[0];
        } else {
        return(string[0] + (string[1] << 8));
        }
    }
    /*
     * Skip to next node
     */
        if ((tmp->children != NULL) &&
            (tmp->type != XML_DTD_NODE) &&
            (tmp->type != XML_ENTITY_REF_NODE) &&
            (tmp->children->type != XML_ENTITY_DECL)) {
            tmp = tmp->children;
            continue;
    }
    if (tmp == node)
        break;
 
    if (tmp->next != NULL) {
        tmp = tmp->next;
        continue;
    }
 
    do {
        tmp = tmp->parent;
        if (tmp == NULL)
        break;
        if (tmp == node) {
        tmp = NULL;
        break;
        }
        if (tmp->next != NULL) {
        tmp = tmp->next;
        break;
        }
    } while (tmp != NULL);
    }
    return(ret);
}
 
static unsigned int
xmlXPathStringHash(const xmlChar * string) {
    if (string == NULL)
    return(0);
    if (string[0] == 0)
    return(0);
    return(string[0] + (string[1] << 8));
}
 
static int
xmlXPathCompareNodeSetFloat(xmlXPathParserContextPtr ctxt, int inf, int strict,
                        xmlXPathObjectPtr arg, xmlXPathObjectPtr f) {
    int i, ret = 0;
    xmlNodeSetPtr ns;
    xmlChar *str2;
 
    if ((f == NULL) || (arg == NULL) ||
    ((arg->type != XPATH_NODESET) && (arg->type != XPATH_XSLT_TREE))) {
    xmlXPathReleaseObject(ctxt->context, arg);
    xmlXPathReleaseObject(ctxt->context, f);
        return(0);
    }
    ns = arg->nodesetval;
    if (ns != NULL) {
    for (i = 0;i < ns->nodeNr;i++) {
         str2 = xmlXPathCastNodeToString(ns->nodeTab[i]);
         if (str2 != NULL) {
         valuePush(ctxt,
               xmlXPathCacheNewString(ctxt->context, str2));
         xmlFree(str2);
         xmlXPathNumberFunction(ctxt, 1);
         valuePush(ctxt, xmlXPathCacheObjectCopy(ctxt->context, f));
         ret = xmlXPathCompareValues(ctxt, inf, strict);
         if (ret)
             break;
         }
    }
    }
    xmlXPathReleaseObject(ctxt->context, arg);
    xmlXPathReleaseObject(ctxt->context, f);
    return(ret);
}
 
static int
xmlXPathCompareNodeSetString(xmlXPathParserContextPtr ctxt, int inf, int strict,
                        xmlXPathObjectPtr arg, xmlXPathObjectPtr s) {
    int i, ret = 0;
    xmlNodeSetPtr ns;
    xmlChar *str2;
 
    if ((s == NULL) || (arg == NULL) ||
    ((arg->type != XPATH_NODESET) && (arg->type != XPATH_XSLT_TREE))) {
    xmlXPathReleaseObject(ctxt->context, arg);
    xmlXPathReleaseObject(ctxt->context, s);
        return(0);
    }
    ns = arg->nodesetval;
    if (ns != NULL) {
    for (i = 0;i < ns->nodeNr;i++) {
         str2 = xmlXPathCastNodeToString(ns->nodeTab[i]);
         if (str2 != NULL) {
         valuePush(ctxt,
               xmlXPathCacheNewString(ctxt->context, str2));
         xmlFree(str2);
         valuePush(ctxt, xmlXPathCacheObjectCopy(ctxt->context, s));
         ret = xmlXPathCompareValues(ctxt, inf, strict);
         if (ret)
             break;
         }
    }
    }
    xmlXPathReleaseObject(ctxt->context, arg);
    xmlXPathReleaseObject(ctxt->context, s);
    return(ret);
}
 
static int
xmlXPathCompareNodeSets(int inf, int strict,
                    xmlXPathObjectPtr arg1, xmlXPathObjectPtr arg2) {
    int i, j, init = 0;
    double val1;
    double *values2;
    int ret = 0;
    xmlNodeSetPtr ns1;
    xmlNodeSetPtr ns2;
 
    if ((arg1 == NULL) ||
    ((arg1->type != XPATH_NODESET) && (arg1->type != XPATH_XSLT_TREE))) {
    xmlXPathFreeObject(arg2);
        return(0);
    }
    if ((arg2 == NULL) ||
    ((arg2->type != XPATH_NODESET) && (arg2->type != XPATH_XSLT_TREE))) {
    xmlXPathFreeObject(arg1);
    xmlXPathFreeObject(arg2);
        return(0);
    }
 
    ns1 = arg1->nodesetval;
    ns2 = arg2->nodesetval;
 
    if ((ns1 == NULL) || (ns1->nodeNr <= 0)) {
    xmlXPathFreeObject(arg1);
    xmlXPathFreeObject(arg2);
    return(0);
    }
    if ((ns2 == NULL) || (ns2->nodeNr <= 0)) {
    xmlXPathFreeObject(arg1);
    xmlXPathFreeObject(arg2);
    return(0);
    }
 
    values2 = (double *) xmlMalloc(ns2->nodeNr * sizeof(double));
    if (values2 == NULL) {
        /* TODO: Propagate memory error. */
        xmlXPathErrMemory(NULL, "comparing nodesets\n");
    xmlXPathFreeObject(arg1);
    xmlXPathFreeObject(arg2);
    return(0);
    }
    for (i = 0;i < ns1->nodeNr;i++) {
    val1 = xmlXPathCastNodeToNumber(ns1->nodeTab[i]);
    if (xmlXPathIsNaN(val1))
        continue;
    for (j = 0;j < ns2->nodeNr;j++) {
        if (init == 0) {
        values2[j] = xmlXPathCastNodeToNumber(ns2->nodeTab[j]);
        }
        if (xmlXPathIsNaN(values2[j]))
        continue;
        if (inf && strict)
        ret = (val1 < values2[j]);
        else if (inf && !strict)
        ret = (val1 <= values2[j]);
        else if (!inf && strict)
        ret = (val1 > values2[j]);
        else if (!inf && !strict)
        ret = (val1 >= values2[j]);
        if (ret)
        break;
    }
    if (ret)
        break;
    init = 1;
    }
    xmlFree(values2);
    xmlXPathFreeObject(arg1);
    xmlXPathFreeObject(arg2);
    return(ret);
}
 
static int
xmlXPathCompareNodeSetValue(xmlXPathParserContextPtr ctxt, int inf, int strict,
                        xmlXPathObjectPtr arg, xmlXPathObjectPtr val) {
    if ((val == NULL) || (arg == NULL) ||
    ((arg->type != XPATH_NODESET) && (arg->type != XPATH_XSLT_TREE)))
        return(0);
 
    switch(val->type) {
        case XPATH_NUMBER:
        return(xmlXPathCompareNodeSetFloat(ctxt, inf, strict, arg, val));
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
        return(xmlXPathCompareNodeSets(inf, strict, arg, val));
        case XPATH_STRING:
        return(xmlXPathCompareNodeSetString(ctxt, inf, strict, arg, val));
        case XPATH_BOOLEAN:
        valuePush(ctxt, arg);
        xmlXPathBooleanFunction(ctxt, 1);
        valuePush(ctxt, val);
        return(xmlXPathCompareValues(ctxt, inf, strict));
    default:
            xmlGenericError(xmlGenericErrorContext,
                    "xmlXPathCompareNodeSetValue: Can't compare node set "
                    "and object of type %d\n",
                    val->type);
            xmlXPathReleaseObject(ctxt->context, arg);
            xmlXPathReleaseObject(ctxt->context, val);
            XP_ERROR0(XPATH_INVALID_TYPE);
    }
    return(0);
}
 
static int
xmlXPathEqualNodeSetString(xmlXPathObjectPtr arg, const xmlChar * str, int neq)
{
    int i;
    xmlNodeSetPtr ns;
    xmlChar *str2;
    unsigned int hash;
 
    if ((str == NULL) || (arg == NULL) ||
        ((arg->type != XPATH_NODESET) && (arg->type != XPATH_XSLT_TREE)))
        return (0);
    ns = arg->nodesetval;
    /*
     * A NULL nodeset compared with a string is always false
     * (since there is no node equal, and no node not equal)
     */
    if ((ns == NULL) || (ns->nodeNr <= 0) )
        return (0);
    hash = xmlXPathStringHash(str);
    for (i = 0; i < ns->nodeNr; i++) {
        if (xmlXPathNodeValHash(ns->nodeTab[i]) == hash) {
            str2 = xmlNodeGetContent(ns->nodeTab[i]);
            if ((str2 != NULL) && (xmlStrEqual(str, str2))) {
                xmlFree(str2);
        if (neq)
            continue;
                return (1);
        } else if ((str2 == NULL) && (xmlStrEqual(str, BAD_CAST ""))) {
        if (neq)
            continue;
                return (1);
            } else if (neq) {
        if (str2 != NULL)
            xmlFree(str2);
        return (1);
        }
            if (str2 != NULL)
                xmlFree(str2);
        } else if (neq)
        return (1);
    }
    return (0);
}
 
static int
xmlXPathEqualNodeSetFloat(xmlXPathParserContextPtr ctxt,
    xmlXPathObjectPtr arg, double f, int neq) {
  int i, ret=0;
  xmlNodeSetPtr ns;
  xmlChar *str2;
  xmlXPathObjectPtr val;
  double v;
 
    if ((arg == NULL) ||
    ((arg->type != XPATH_NODESET) && (arg->type != XPATH_XSLT_TREE)))
        return(0);
 
    ns = arg->nodesetval;
    if (ns != NULL) {
    for (i=0;i<ns->nodeNr;i++) {
        str2 = xmlXPathCastNodeToString(ns->nodeTab[i]);
        if (str2 != NULL) {
        valuePush(ctxt, xmlXPathCacheNewString(ctxt->context, str2));
        xmlFree(str2);
        xmlXPathNumberFunction(ctxt, 1);
                CHECK_ERROR0;
        val = valuePop(ctxt);
        v = val->floatval;
        xmlXPathReleaseObject(ctxt->context, val);
        if (!xmlXPathIsNaN(v)) {
            if ((!neq) && (v==f)) {
            ret = 1;
            break;
            } else if ((neq) && (v!=f)) {
            ret = 1;
            break;
            }
        } else {    /* NaN is unequal to any value */
            if (neq)
            ret = 1;
        }
        }
    }
    }
 
    return(ret);
}
 
 
static int
xmlXPathEqualNodeSets(xmlXPathObjectPtr arg1, xmlXPathObjectPtr arg2, int neq) {
    int i, j;
    unsigned int *hashs1;
    unsigned int *hashs2;
    xmlChar **values1;
    xmlChar **values2;
    int ret = 0;
    xmlNodeSetPtr ns1;
    xmlNodeSetPtr ns2;
 
    if ((arg1 == NULL) ||
    ((arg1->type != XPATH_NODESET) && (arg1->type != XPATH_XSLT_TREE)))
        return(0);
    if ((arg2 == NULL) ||
    ((arg2->type != XPATH_NODESET) && (arg2->type != XPATH_XSLT_TREE)))
        return(0);
 
    ns1 = arg1->nodesetval;
    ns2 = arg2->nodesetval;
 
    if ((ns1 == NULL) || (ns1->nodeNr <= 0))
    return(0);
    if ((ns2 == NULL) || (ns2->nodeNr <= 0))
    return(0);
 
    /*
     * for equal, check if there is a node pertaining to both sets
     */
    if (neq == 0)
    for (i = 0;i < ns1->nodeNr;i++)
        for (j = 0;j < ns2->nodeNr;j++)
        if (ns1->nodeTab[i] == ns2->nodeTab[j])
            return(1);
 
    values1 = (xmlChar **) xmlMalloc(ns1->nodeNr * sizeof(xmlChar *));
    if (values1 == NULL) {
        /* TODO: Propagate memory error. */
        xmlXPathErrMemory(NULL, "comparing nodesets\n");
    return(0);
    }
    hashs1 = (unsigned int *) xmlMalloc(ns1->nodeNr * sizeof(unsigned int));
    if (hashs1 == NULL) {
        /* TODO: Propagate memory error. */
        xmlXPathErrMemory(NULL, "comparing nodesets\n");
    xmlFree(values1);
    return(0);
    }
    memset(values1, 0, ns1->nodeNr * sizeof(xmlChar *));
    values2 = (xmlChar **) xmlMalloc(ns2->nodeNr * sizeof(xmlChar *));
    if (values2 == NULL) {
        /* TODO: Propagate memory error. */
        xmlXPathErrMemory(NULL, "comparing nodesets\n");
    xmlFree(hashs1);
    xmlFree(values1);
    return(0);
    }
    hashs2 = (unsigned int *) xmlMalloc(ns2->nodeNr * sizeof(unsigned int));
    if (hashs2 == NULL) {
        /* TODO: Propagate memory error. */
        xmlXPathErrMemory(NULL, "comparing nodesets\n");
    xmlFree(hashs1);
    xmlFree(values1);
    xmlFree(values2);
    return(0);
    }
    memset(values2, 0, ns2->nodeNr * sizeof(xmlChar *));
    for (i = 0;i < ns1->nodeNr;i++) {
    hashs1[i] = xmlXPathNodeValHash(ns1->nodeTab[i]);
    for (j = 0;j < ns2->nodeNr;j++) {
        if (i == 0)
        hashs2[j] = xmlXPathNodeValHash(ns2->nodeTab[j]);
        if (hashs1[i] != hashs2[j]) {
        if (neq) {
            ret = 1;
            break;
        }
        }
        else {
        if (values1[i] == NULL)
            values1[i] = xmlNodeGetContent(ns1->nodeTab[i]);
        if (values2[j] == NULL)
            values2[j] = xmlNodeGetContent(ns2->nodeTab[j]);
        ret = xmlStrEqual(values1[i], values2[j]) ^ neq;
        if (ret)
            break;
        }
    }
    if (ret)
        break;
    }
    for (i = 0;i < ns1->nodeNr;i++)
    if (values1[i] != NULL)
        xmlFree(values1[i]);
    for (j = 0;j < ns2->nodeNr;j++)
    if (values2[j] != NULL)
        xmlFree(values2[j]);
    xmlFree(values1);
    xmlFree(values2);
    xmlFree(hashs1);
    xmlFree(hashs2);
    return(ret);
}
 
static int
xmlXPathEqualValuesCommon(xmlXPathParserContextPtr ctxt,
  xmlXPathObjectPtr arg1, xmlXPathObjectPtr arg2) {
    int ret = 0;
    /*
     *At this point we are assured neither arg1 nor arg2
     *is a nodeset, so we can just pick the appropriate routine.
     */
    switch (arg1->type) {
        case XPATH_UNDEFINED:
        break;
        case XPATH_BOOLEAN:
        switch (arg2->type) {
            case XPATH_UNDEFINED:
            break;
        case XPATH_BOOLEAN:
            ret = (arg1->boolval == arg2->boolval);
            break;
        case XPATH_NUMBER:
            ret = (arg1->boolval ==
               xmlXPathCastNumberToBoolean(arg2->floatval));
            break;
        case XPATH_STRING:
            if ((arg2->stringval == NULL) ||
            (arg2->stringval[0] == 0)) ret = 0;
            else
            ret = 1;
            ret = (arg1->boolval == ret);
            break;
        case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_POINT:
        case XPATH_RANGE:
        case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
            TODO
            break;
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
            break;
        }
        break;
        case XPATH_NUMBER:
        switch (arg2->type) {
            case XPATH_UNDEFINED:
            break;
        case XPATH_BOOLEAN:
            ret = (arg2->boolval==
               xmlXPathCastNumberToBoolean(arg1->floatval));
            break;
        case XPATH_STRING:
            valuePush(ctxt, arg2);
            xmlXPathNumberFunction(ctxt, 1);
            arg2 = valuePop(ctxt);
                    if (ctxt->error)
                        break;
                    /* Falls through. */
        case XPATH_NUMBER:
            /* Hand check NaN and Infinity equalities */
            if (xmlXPathIsNaN(arg1->floatval) ||
                xmlXPathIsNaN(arg2->floatval)) {
                ret = 0;
            } else if (xmlXPathIsInf(arg1->floatval) == 1) {
                if (xmlXPathIsInf(arg2->floatval) == 1)
                ret = 1;
            else
                ret = 0;
            } else if (xmlXPathIsInf(arg1->floatval) == -1) {
            if (xmlXPathIsInf(arg2->floatval) == -1)
                ret = 1;
            else
                ret = 0;
            } else if (xmlXPathIsInf(arg2->floatval) == 1) {
            if (xmlXPathIsInf(arg1->floatval) == 1)
                ret = 1;
            else
                ret = 0;
            } else if (xmlXPathIsInf(arg2->floatval) == -1) {
            if (xmlXPathIsInf(arg1->floatval) == -1)
                ret = 1;
            else
                ret = 0;
            } else {
                ret = (arg1->floatval == arg2->floatval);
            }
            break;
        case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_POINT:
        case XPATH_RANGE:
        case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
            TODO
            break;
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
            break;
        }
        break;
        case XPATH_STRING:
        switch (arg2->type) {
            case XPATH_UNDEFINED:
            break;
        case XPATH_BOOLEAN:
            if ((arg1->stringval == NULL) ||
            (arg1->stringval[0] == 0)) ret = 0;
            else
            ret = 1;
            ret = (arg2->boolval == ret);
            break;
        case XPATH_STRING:
            ret = xmlStrEqual(arg1->stringval, arg2->stringval);
            break;
        case XPATH_NUMBER:
            valuePush(ctxt, arg1);
            xmlXPathNumberFunction(ctxt, 1);
            arg1 = valuePop(ctxt);
                    if (ctxt->error)
                        break;
            /* Hand check NaN and Infinity equalities */
            if (xmlXPathIsNaN(arg1->floatval) ||
                xmlXPathIsNaN(arg2->floatval)) {
                ret = 0;
            } else if (xmlXPathIsInf(arg1->floatval) == 1) {
            if (xmlXPathIsInf(arg2->floatval) == 1)
                ret = 1;
            else
                ret = 0;
            } else if (xmlXPathIsInf(arg1->floatval) == -1) {
            if (xmlXPathIsInf(arg2->floatval) == -1)
                ret = 1;
            else
                ret = 0;
            } else if (xmlXPathIsInf(arg2->floatval) == 1) {
            if (xmlXPathIsInf(arg1->floatval) == 1)
                ret = 1;
            else
                ret = 0;
            } else if (xmlXPathIsInf(arg2->floatval) == -1) {
            if (xmlXPathIsInf(arg1->floatval) == -1)
                ret = 1;
            else
                ret = 0;
            } else {
                ret = (arg1->floatval == arg2->floatval);
            }
            break;
        case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_POINT:
        case XPATH_RANGE:
        case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
            TODO
            break;
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
            break;
        }
        break;
        case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_POINT:
    case XPATH_RANGE:
    case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
        TODO
        break;
    case XPATH_NODESET:
    case XPATH_XSLT_TREE:
        break;
    }
    xmlXPathReleaseObject(ctxt->context, arg1);
    xmlXPathReleaseObject(ctxt->context, arg2);
    return(ret);
}
 
int
xmlXPathEqualValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg1, arg2, argtmp;
    int ret = 0;
 
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(0);
    arg2 = valuePop(ctxt);
    arg1 = valuePop(ctxt);
    if ((arg1 == NULL) || (arg2 == NULL)) {
    if (arg1 != NULL)
        xmlXPathReleaseObject(ctxt->context, arg1);
    else
        xmlXPathReleaseObject(ctxt->context, arg2);
    XP_ERROR0(XPATH_INVALID_OPERAND);
    }
 
    if (arg1 == arg2) {
    xmlXPathFreeObject(arg1);
        return(1);
    }
 
    /*
     *If either argument is a nodeset, it's a 'special case'
     */
    if ((arg2->type == XPATH_NODESET) || (arg2->type == XPATH_XSLT_TREE) ||
      (arg1->type == XPATH_NODESET) || (arg1->type == XPATH_XSLT_TREE)) {
    /*
     *Hack it to assure arg1 is the nodeset
     */
    if ((arg1->type != XPATH_NODESET) && (arg1->type != XPATH_XSLT_TREE)) {
        argtmp = arg2;
        arg2 = arg1;
        arg1 = argtmp;
    }
    switch (arg2->type) {
        case XPATH_UNDEFINED:
        break;
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
        ret = xmlXPathEqualNodeSets(arg1, arg2, 0);
        break;
        case XPATH_BOOLEAN:
        if ((arg1->nodesetval == NULL) ||
          (arg1->nodesetval->nodeNr == 0)) ret = 0;
        else
            ret = 1;
        ret = (ret == arg2->boolval);
        break;
        case XPATH_NUMBER:
        ret = xmlXPathEqualNodeSetFloat(ctxt, arg1, arg2->floatval, 0);
        break;
        case XPATH_STRING:
        ret = xmlXPathEqualNodeSetString(arg1, arg2->stringval, 0);
        break;
        case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_POINT:
        case XPATH_RANGE:
        case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
        TODO
        break;
    }
    xmlXPathReleaseObject(ctxt->context, arg1);
    xmlXPathReleaseObject(ctxt->context, arg2);
    return(ret);
    }
 
    return (xmlXPathEqualValuesCommon(ctxt, arg1, arg2));
}
 
int
xmlXPathNotEqualValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg1, arg2, argtmp;
    int ret = 0;
 
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(0);
    arg2 = valuePop(ctxt);
    arg1 = valuePop(ctxt);
    if ((arg1 == NULL) || (arg2 == NULL)) {
    if (arg1 != NULL)
        xmlXPathReleaseObject(ctxt->context, arg1);
    else
        xmlXPathReleaseObject(ctxt->context, arg2);
    XP_ERROR0(XPATH_INVALID_OPERAND);
    }
 
    if (arg1 == arg2) {
    xmlXPathReleaseObject(ctxt->context, arg1);
        return(0);
    }
 
    /*
     *If either argument is a nodeset, it's a 'special case'
     */
    if ((arg2->type == XPATH_NODESET) || (arg2->type == XPATH_XSLT_TREE) ||
      (arg1->type == XPATH_NODESET) || (arg1->type == XPATH_XSLT_TREE)) {
    /*
     *Hack it to assure arg1 is the nodeset
     */
    if ((arg1->type != XPATH_NODESET) && (arg1->type != XPATH_XSLT_TREE)) {
        argtmp = arg2;
        arg2 = arg1;
        arg1 = argtmp;
    }
    switch (arg2->type) {
        case XPATH_UNDEFINED:
        break;
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
        ret = xmlXPathEqualNodeSets(arg1, arg2, 1);
        break;
        case XPATH_BOOLEAN:
        if ((arg1->nodesetval == NULL) ||
          (arg1->nodesetval->nodeNr == 0)) ret = 0;
        else
            ret = 1;
        ret = (ret != arg2->boolval);
        break;
        case XPATH_NUMBER:
        ret = xmlXPathEqualNodeSetFloat(ctxt, arg1, arg2->floatval, 1);
        break;
        case XPATH_STRING:
        ret = xmlXPathEqualNodeSetString(arg1, arg2->stringval,1);
        break;
        case XPATH_USERS:
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_POINT:
        case XPATH_RANGE:
        case XPATH_LOCATIONSET:
#endif /* LIBXML_XPTR_LOCS_ENABLED */
        TODO
        break;
    }
    xmlXPathReleaseObject(ctxt->context, arg1);
    xmlXPathReleaseObject(ctxt->context, arg2);
    return(ret);
    }
 
    return (!xmlXPathEqualValuesCommon(ctxt, arg1, arg2));
}
 
int
xmlXPathCompareValues(xmlXPathParserContextPtr ctxt, int inf, int strict) {
    int ret = 0, arg1i = 0, arg2i = 0;
    xmlXPathObjectPtr arg1, arg2;
 
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(0);
    arg2 = valuePop(ctxt);
    arg1 = valuePop(ctxt);
    if ((arg1 == NULL) || (arg2 == NULL)) {
    if (arg1 != NULL)
        xmlXPathReleaseObject(ctxt->context, arg1);
    else
        xmlXPathReleaseObject(ctxt->context, arg2);
    XP_ERROR0(XPATH_INVALID_OPERAND);
    }
 
    if ((arg2->type == XPATH_NODESET) || (arg2->type == XPATH_XSLT_TREE) ||
      (arg1->type == XPATH_NODESET) || (arg1->type == XPATH_XSLT_TREE)) {
    /*
     * If either argument is a XPATH_NODESET or XPATH_XSLT_TREE the two arguments
     * are not freed from within this routine; they will be freed from the
     * called routine, e.g. xmlXPathCompareNodeSets or xmlXPathCompareNodeSetValue
     */
    if (((arg2->type == XPATH_NODESET) || (arg2->type == XPATH_XSLT_TREE)) &&
      ((arg1->type == XPATH_NODESET) || (arg1->type == XPATH_XSLT_TREE))){
        ret = xmlXPathCompareNodeSets(inf, strict, arg1, arg2);
    } else {
        if ((arg1->type == XPATH_NODESET) || (arg1->type == XPATH_XSLT_TREE)) {
        ret = xmlXPathCompareNodeSetValue(ctxt, inf, strict,
                                      arg1, arg2);
        } else {
        ret = xmlXPathCompareNodeSetValue(ctxt, !inf, strict,
                                      arg2, arg1);
        }
    }
    return(ret);
    }
 
    if (arg1->type != XPATH_NUMBER) {
    valuePush(ctxt, arg1);
    xmlXPathNumberFunction(ctxt, 1);
    arg1 = valuePop(ctxt);
    }
    if (arg2->type != XPATH_NUMBER) {
    valuePush(ctxt, arg2);
    xmlXPathNumberFunction(ctxt, 1);
    arg2 = valuePop(ctxt);
    }
    if (ctxt->error)
        goto error;
    /*
     * Add tests for infinity and nan
     * => feedback on 3.4 for Inf and NaN
     */
    /* Hand check NaN and Infinity comparisons */
    if (xmlXPathIsNaN(arg1->floatval) || xmlXPathIsNaN(arg2->floatval)) {
    ret=0;
    } else {
    arg1i=xmlXPathIsInf(arg1->floatval);
    arg2i=xmlXPathIsInf(arg2->floatval);
    if (inf && strict) {
        if ((arg1i == -1 && arg2i != -1) ||
        (arg2i == 1 && arg1i != 1)) {
        ret = 1;
        } else if (arg1i == 0 && arg2i == 0) {
        ret = (arg1->floatval < arg2->floatval);
        } else {
        ret = 0;
        }
    }
    else if (inf && !strict) {
        if (arg1i == -1 || arg2i == 1) {
        ret = 1;
        } else if (arg1i == 0 && arg2i == 0) {
        ret = (arg1->floatval <= arg2->floatval);
        } else {
        ret = 0;
        }
    }
    else if (!inf && strict) {
        if ((arg1i == 1 && arg2i != 1) ||
        (arg2i == -1 && arg1i != -1)) {
        ret = 1;
        } else if (arg1i == 0 && arg2i == 0) {
        ret = (arg1->floatval > arg2->floatval);
        } else {
        ret = 0;
        }
    }
    else if (!inf && !strict) {
        if (arg1i == 1 || arg2i == -1) {
        ret = 1;
        } else if (arg1i == 0 && arg2i == 0) {
        ret = (arg1->floatval >= arg2->floatval);
        } else {
        ret = 0;
        }
    }
    }
error:
    xmlXPathReleaseObject(ctxt->context, arg1);
    xmlXPathReleaseObject(ctxt->context, arg2);
    return(ret);
}
 
void
xmlXPathValueFlipSign(xmlXPathParserContextPtr ctxt) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return;
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
    ctxt->value->floatval = -ctxt->value->floatval;
}
 
void
xmlXPathAddValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;
 
    arg = valuePop(ctxt);
    if (arg == NULL)
    XP_ERROR(XPATH_INVALID_OPERAND);
    val = xmlXPathCastToNumber(arg);
    xmlXPathReleaseObject(ctxt->context, arg);
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
    ctxt->value->floatval += val;
}
 
void
xmlXPathSubValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;
 
    arg = valuePop(ctxt);
    if (arg == NULL)
    XP_ERROR(XPATH_INVALID_OPERAND);
    val = xmlXPathCastToNumber(arg);
    xmlXPathReleaseObject(ctxt->context, arg);
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
    ctxt->value->floatval -= val;
}
 
void
xmlXPathMultValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;
 
    arg = valuePop(ctxt);
    if (arg == NULL)
    XP_ERROR(XPATH_INVALID_OPERAND);
    val = xmlXPathCastToNumber(arg);
    xmlXPathReleaseObject(ctxt->context, arg);
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
    ctxt->value->floatval *= val;
}
 
ATTRIBUTE_NO_SANITIZE("float-divide-by-zero")
void
xmlXPathDivValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double val;
 
    arg = valuePop(ctxt);
    if (arg == NULL)
    XP_ERROR(XPATH_INVALID_OPERAND);
    val = xmlXPathCastToNumber(arg);
    xmlXPathReleaseObject(ctxt->context, arg);
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
    ctxt->value->floatval /= val;
}
 
void
xmlXPathModValues(xmlXPathParserContextPtr ctxt) {
    xmlXPathObjectPtr arg;
    double arg1, arg2;
 
    arg = valuePop(ctxt);
    if (arg == NULL)
    XP_ERROR(XPATH_INVALID_OPERAND);
    arg2 = xmlXPathCastToNumber(arg);
    xmlXPathReleaseObject(ctxt->context, arg);
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
    arg1 = ctxt->value->floatval;
    if (arg2 == 0)
    ctxt->value->floatval = xmlXPathNAN;
    else {
    ctxt->value->floatval = fmod(arg1, arg2);
    }
}
 
/************************************************************************
 *                                  *
 *      The traversal functions                 *
 *                                  *
 ************************************************************************/
 
/*
 * A traversal function enumerates nodes along an axis.
 * Initially it must be called with NULL, and it indicates
 * termination on the axis by returning NULL.
 */
typedef xmlNodePtr (*xmlXPathTraversalFunction)
                    (xmlXPathParserContextPtr ctxt, xmlNodePtr cur);
 
/*
 * xmlXPathTraversalFunctionExt:
 * A traversal function enumerates nodes along an axis.
 * Initially it must be called with NULL, and it indicates
 * termination on the axis by returning NULL.
 * The context node of the traversal is specified via @contextNode.
 */
typedef xmlNodePtr (*xmlXPathTraversalFunctionExt)
                    (xmlNodePtr cur, xmlNodePtr contextNode);
 
/*
 * xmlXPathNodeSetMergeFunction:
 * Used for merging node sets in xmlXPathCollectAndTest().
 */
typedef xmlNodeSetPtr (*xmlXPathNodeSetMergeFunction)
            (xmlNodeSetPtr, xmlNodeSetPtr);
 
 
xmlNodePtr
xmlXPathNextSelf(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (cur == NULL)
        return(ctxt->context->node);
    return(NULL);
}
 
xmlNodePtr
xmlXPathNextChild(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (cur == NULL) {
    if (ctxt->context->node == NULL) return(NULL);
    switch (ctxt->context->node->type) {
            case XML_ELEMENT_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_ENTITY_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
            case XML_NOTATION_NODE:
            case XML_DTD_NODE:
        return(ctxt->context->node->children);
            case XML_DOCUMENT_NODE:
            case XML_DOCUMENT_TYPE_NODE:
            case XML_DOCUMENT_FRAG_NODE:
            case XML_HTML_DOCUMENT_NODE:
        return(((xmlDocPtr) ctxt->context->node)->children);
        case XML_ELEMENT_DECL:
        case XML_ATTRIBUTE_DECL:
        case XML_ENTITY_DECL:
            case XML_ATTRIBUTE_NODE:
        case XML_NAMESPACE_DECL:
        case XML_XINCLUDE_START:
        case XML_XINCLUDE_END:
        return(NULL);
    }
    return(NULL);
    }
    if ((cur->type == XML_DOCUMENT_NODE) ||
        (cur->type == XML_HTML_DOCUMENT_NODE))
    return(NULL);
    return(cur->next);
}
 
static xmlNodePtr
xmlXPathNextChildElement(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (cur == NULL) {
    cur = ctxt->context->node;
    if (cur == NULL) return(NULL);
    /*
    * Get the first element child.
    */
    switch (cur->type) {
            case XML_ELEMENT_NODE:
        case XML_DOCUMENT_FRAG_NODE:
        case XML_ENTITY_REF_NODE: /* URGENT TODO: entify-refs as well? */
            case XML_ENTITY_NODE:
        cur = cur->children;
        if (cur != NULL) {
            if (cur->type == XML_ELEMENT_NODE)
            return(cur);
            do {
            cur = cur->next;
            } while ((cur != NULL) &&
            (cur->type != XML_ELEMENT_NODE));
            return(cur);
        }
        return(NULL);
            case XML_DOCUMENT_NODE:
            case XML_HTML_DOCUMENT_NODE:
        return(xmlDocGetRootElement((xmlDocPtr) cur));
        default:
        return(NULL);
    }
    return(NULL);
    }
    /*
    * Get the next sibling element node.
    */
    switch (cur->type) {
    case XML_ELEMENT_NODE:
    case XML_TEXT_NODE:
    case XML_ENTITY_REF_NODE:
    case XML_ENTITY_NODE:
    case XML_CDATA_SECTION_NODE:
    case XML_PI_NODE:
    case XML_COMMENT_NODE:
    case XML_XINCLUDE_END:
        break;
    /* case XML_DTD_NODE: */ /* URGENT TODO: DTD-node as well? */
    default:
        return(NULL);
    }
    if (cur->next != NULL) {
    if (cur->next->type == XML_ELEMENT_NODE)
        return(cur->next);
    cur = cur->next;
    do {
        cur = cur->next;
    } while ((cur != NULL) && (cur->type != XML_ELEMENT_NODE));
    return(cur);
    }
    return(NULL);
}
 
#if 0
static xmlNodePtr
xmlXPathNextDescendantOrSelfElemParent(xmlNodePtr cur,
                       xmlNodePtr contextNode)
{
    if (cur == NULL) {
    if (contextNode == NULL)
        return(NULL);
    switch (contextNode->type) {
        case XML_ELEMENT_NODE:
        case XML_XINCLUDE_START:
        case XML_DOCUMENT_FRAG_NODE:
        case XML_DOCUMENT_NODE:
        case XML_HTML_DOCUMENT_NODE:
        return(contextNode);
        default:
        return(NULL);
    }
    return(NULL);
    } else {
    xmlNodePtr start = cur;
 
    while (cur != NULL) {
        switch (cur->type) {
        case XML_ELEMENT_NODE:
        /* TODO: OK to have XInclude here? */
        case XML_XINCLUDE_START:
        case XML_DOCUMENT_FRAG_NODE:
            if (cur != start)
            return(cur);
            if (cur->children != NULL) {
            cur = cur->children;
            continue;
            }
            break;
        /* Not sure if we need those here. */
        case XML_DOCUMENT_NODE:
        case XML_HTML_DOCUMENT_NODE:
            if (cur != start)
            return(cur);
            return(xmlDocGetRootElement((xmlDocPtr) cur));
        default:
            break;
        }
 
next_sibling:
        if ((cur == NULL) || (cur == contextNode))
        return(NULL);
        if (cur->next != NULL) {
        cur = cur->next;
        } else {
        cur = cur->parent;
        goto next_sibling;
        }
    }
    }
    return(NULL);
}
#endif
 
xmlNodePtr
xmlXPathNextDescendant(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (cur == NULL) {
    if (ctxt->context->node == NULL)
        return(NULL);
    if ((ctxt->context->node->type == XML_ATTRIBUTE_NODE) ||
        (ctxt->context->node->type == XML_NAMESPACE_DECL))
        return(NULL);
 
        if (ctxt->context->node == (xmlNodePtr) ctxt->context->doc)
        return(ctxt->context->doc->children);
        return(ctxt->context->node->children);
    }
 
    if (cur->type == XML_NAMESPACE_DECL)
        return(NULL);
    if (cur->children != NULL) {
    /*
     * Do not descend on entities declarations
     */
    if (cur->children->type != XML_ENTITY_DECL) {
        cur = cur->children;
        /*
         * Skip DTDs
         */
        if (cur->type != XML_DTD_NODE)
        return(cur);
    }
    }
 
    if (cur == ctxt->context->node) return(NULL);
 
    while (cur->next != NULL) {
    cur = cur->next;
    if ((cur->type != XML_ENTITY_DECL) &&
        (cur->type != XML_DTD_NODE))
        return(cur);
    }
 
    do {
        cur = cur->parent;
    if (cur == NULL) break;
    if (cur == ctxt->context->node) return(NULL);
    if (cur->next != NULL) {
        cur = cur->next;
        return(cur);
    }
    } while (cur != NULL);
    return(cur);
}
 
xmlNodePtr
xmlXPathNextDescendantOrSelf(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (cur == NULL)
        return(ctxt->context->node);
 
    if (ctxt->context->node == NULL)
        return(NULL);
    if ((ctxt->context->node->type == XML_ATTRIBUTE_NODE) ||
        (ctxt->context->node->type == XML_NAMESPACE_DECL))
        return(NULL);
 
    return(xmlXPathNextDescendant(ctxt, cur));
}
 
xmlNodePtr
xmlXPathNextParent(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    /*
     * the parent of an attribute or namespace node is the element
     * to which the attribute or namespace node is attached
     * Namespace handling !!!
     */
    if (cur == NULL) {
    if (ctxt->context->node == NULL) return(NULL);
    switch (ctxt->context->node->type) {
            case XML_ELEMENT_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_ENTITY_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
            case XML_NOTATION_NODE:
            case XML_DTD_NODE:
        case XML_ELEMENT_DECL:
        case XML_ATTRIBUTE_DECL:
        case XML_XINCLUDE_START:
        case XML_XINCLUDE_END:
        case XML_ENTITY_DECL:
        if (ctxt->context->node->parent == NULL)
            return((xmlNodePtr) ctxt->context->doc);
        if ((ctxt->context->node->parent->type == XML_ELEMENT_NODE) &&
            ((ctxt->context->node->parent->name[0] == ' ') ||
             (xmlStrEqual(ctxt->context->node->parent->name,
                 BAD_CAST "fake node libxslt"))))
            return(NULL);
        return(ctxt->context->node->parent);
            case XML_ATTRIBUTE_NODE: {
        xmlAttrPtr att = (xmlAttrPtr) ctxt->context->node;
 
        return(att->parent);
        }
            case XML_DOCUMENT_NODE:
            case XML_DOCUMENT_TYPE_NODE:
            case XML_DOCUMENT_FRAG_NODE:
            case XML_HTML_DOCUMENT_NODE:
                return(NULL);
        case XML_NAMESPACE_DECL: {
        xmlNsPtr ns = (xmlNsPtr) ctxt->context->node;
 
        if ((ns->next != NULL) &&
            (ns->next->type != XML_NAMESPACE_DECL))
            return((xmlNodePtr) ns->next);
                return(NULL);
        }
    }
    }
    return(NULL);
}
 
xmlNodePtr
xmlXPathNextAncestor(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    /*
     * the parent of an attribute or namespace node is the element
     * to which the attribute or namespace node is attached
     * !!!!!!!!!!!!!
     */
    if (cur == NULL) {
    if (ctxt->context->node == NULL) return(NULL);
    switch (ctxt->context->node->type) {
            case XML_ELEMENT_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_ENTITY_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
        case XML_DTD_NODE:
        case XML_ELEMENT_DECL:
        case XML_ATTRIBUTE_DECL:
        case XML_ENTITY_DECL:
            case XML_NOTATION_NODE:
        case XML_XINCLUDE_START:
        case XML_XINCLUDE_END:
        if (ctxt->context->node->parent == NULL)
            return((xmlNodePtr) ctxt->context->doc);
        if ((ctxt->context->node->parent->type == XML_ELEMENT_NODE) &&
            ((ctxt->context->node->parent->name[0] == ' ') ||
             (xmlStrEqual(ctxt->context->node->parent->name,
                 BAD_CAST "fake node libxslt"))))
            return(NULL);
        return(ctxt->context->node->parent);
            case XML_ATTRIBUTE_NODE: {
        xmlAttrPtr tmp = (xmlAttrPtr) ctxt->context->node;
 
        return(tmp->parent);
        }
            case XML_DOCUMENT_NODE:
            case XML_DOCUMENT_TYPE_NODE:
            case XML_DOCUMENT_FRAG_NODE:
            case XML_HTML_DOCUMENT_NODE:
                return(NULL);
        case XML_NAMESPACE_DECL: {
        xmlNsPtr ns = (xmlNsPtr) ctxt->context->node;
 
        if ((ns->next != NULL) &&
            (ns->next->type != XML_NAMESPACE_DECL))
            return((xmlNodePtr) ns->next);
        /* Bad, how did that namespace end up here ? */
                return(NULL);
        }
    }
    return(NULL);
    }
    if (cur == ctxt->context->doc->children)
    return((xmlNodePtr) ctxt->context->doc);
    if (cur == (xmlNodePtr) ctxt->context->doc)
    return(NULL);
    switch (cur->type) {
    case XML_ELEMENT_NODE:
    case XML_TEXT_NODE:
    case XML_CDATA_SECTION_NODE:
    case XML_ENTITY_REF_NODE:
    case XML_ENTITY_NODE:
    case XML_PI_NODE:
    case XML_COMMENT_NODE:
    case XML_NOTATION_NODE:
    case XML_DTD_NODE:
        case XML_ELEMENT_DECL:
        case XML_ATTRIBUTE_DECL:
        case XML_ENTITY_DECL:
    case XML_XINCLUDE_START:
    case XML_XINCLUDE_END:
        if (cur->parent == NULL)
        return(NULL);
        if ((cur->parent->type == XML_ELEMENT_NODE) &&
        ((cur->parent->name[0] == ' ') ||
         (xmlStrEqual(cur->parent->name,
                  BAD_CAST "fake node libxslt"))))
        return(NULL);
        return(cur->parent);
    case XML_ATTRIBUTE_NODE: {
        xmlAttrPtr att = (xmlAttrPtr) cur;
 
        return(att->parent);
    }
    case XML_NAMESPACE_DECL: {
        xmlNsPtr ns = (xmlNsPtr) cur;
 
        if ((ns->next != NULL) &&
            (ns->next->type != XML_NAMESPACE_DECL))
            return((xmlNodePtr) ns->next);
        /* Bad, how did that namespace end up here ? */
            return(NULL);
    }
    case XML_DOCUMENT_NODE:
    case XML_DOCUMENT_TYPE_NODE:
    case XML_DOCUMENT_FRAG_NODE:
    case XML_HTML_DOCUMENT_NODE:
        return(NULL);
    }
    return(NULL);
}
 
xmlNodePtr
xmlXPathNextAncestorOrSelf(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (cur == NULL)
        return(ctxt->context->node);
    return(xmlXPathNextAncestor(ctxt, cur));
}
 
xmlNodePtr
xmlXPathNextFollowingSibling(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if ((ctxt->context->node->type == XML_ATTRIBUTE_NODE) ||
    (ctxt->context->node->type == XML_NAMESPACE_DECL))
    return(NULL);
    if (cur == (xmlNodePtr) ctxt->context->doc)
        return(NULL);
    if (cur == NULL)
        return(ctxt->context->node->next);
    return(cur->next);
}
 
xmlNodePtr
xmlXPathNextPrecedingSibling(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if ((ctxt->context->node->type == XML_ATTRIBUTE_NODE) ||
    (ctxt->context->node->type == XML_NAMESPACE_DECL))
    return(NULL);
    if (cur == (xmlNodePtr) ctxt->context->doc)
        return(NULL);
    if (cur == NULL)
        return(ctxt->context->node->prev);
    if ((cur->prev != NULL) && (cur->prev->type == XML_DTD_NODE)) {
    cur = cur->prev;
    if (cur == NULL)
        return(ctxt->context->node->prev);
    }
    return(cur->prev);
}
 
xmlNodePtr
xmlXPathNextFollowing(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if ((cur != NULL) && (cur->type  != XML_ATTRIBUTE_NODE) &&
        (cur->type != XML_NAMESPACE_DECL) && (cur->children != NULL))
        return(cur->children);
 
    if (cur == NULL) {
        cur = ctxt->context->node;
        if (cur->type == XML_ATTRIBUTE_NODE) {
            cur = cur->parent;
        } else if (cur->type == XML_NAMESPACE_DECL) {
            xmlNsPtr ns = (xmlNsPtr) cur;
 
            if ((ns->next == NULL) ||
                (ns->next->type == XML_NAMESPACE_DECL))
                return (NULL);
            cur = (xmlNodePtr) ns->next;
        }
    }
    if (cur == NULL) return(NULL) ; /* ERROR */
    if (cur->next != NULL) return(cur->next) ;
    do {
        cur = cur->parent;
        if (cur == NULL) break;
        if (cur == (xmlNodePtr) ctxt->context->doc) return(NULL);
        if (cur->next != NULL) return(cur->next);
    } while (cur != NULL);
    return(cur);
}
 
/*
 * xmlXPathIsAncestor:
 * @ancestor:  the ancestor node
 * @node:  the current node
 *
 * Check that @ancestor is a @node's ancestor
 *
 * returns 1 if @ancestor is a @node's ancestor, 0 otherwise.
 */
static int
xmlXPathIsAncestor(xmlNodePtr ancestor, xmlNodePtr node) {
    if ((ancestor == NULL) || (node == NULL)) return(0);
    if (node->type == XML_NAMESPACE_DECL)
        return(0);
    if (ancestor->type == XML_NAMESPACE_DECL)
        return(0);
    /* nodes need to be in the same document */
    if (ancestor->doc != node->doc) return(0);
    /* avoid searching if ancestor or node is the root node */
    if (ancestor == (xmlNodePtr) node->doc) return(1);
    if (node == (xmlNodePtr) ancestor->doc) return(0);
    while (node->parent != NULL) {
        if (node->parent == ancestor)
            return(1);
    node = node->parent;
    }
    return(0);
}
 
xmlNodePtr
xmlXPathNextPreceding(xmlXPathParserContextPtr ctxt, xmlNodePtr cur)
{
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (cur == NULL) {
        cur = ctxt->context->node;
        if (cur->type == XML_ATTRIBUTE_NODE) {
            cur = cur->parent;
        } else if (cur->type == XML_NAMESPACE_DECL) {
            xmlNsPtr ns = (xmlNsPtr) cur;
 
            if ((ns->next == NULL) ||
                (ns->next->type == XML_NAMESPACE_DECL))
                return (NULL);
            cur = (xmlNodePtr) ns->next;
        }
    }
    if ((cur == NULL) || (cur->type == XML_NAMESPACE_DECL))
    return (NULL);
    if ((cur->prev != NULL) && (cur->prev->type == XML_DTD_NODE))
    cur = cur->prev;
    do {
        if (cur->prev != NULL) {
            for (cur = cur->prev; cur->last != NULL; cur = cur->last) ;
            return (cur);
        }
 
        cur = cur->parent;
        if (cur == NULL)
            return (NULL);
        if (cur == ctxt->context->doc->children)
            return (NULL);
    } while (xmlXPathIsAncestor(cur, ctxt->context->node));
    return (cur);
}
 
static xmlNodePtr
xmlXPathNextPrecedingInternal(xmlXPathParserContextPtr ctxt,
                              xmlNodePtr cur)
{
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (cur == NULL) {
        cur = ctxt->context->node;
        if (cur == NULL)
            return (NULL);
        if (cur->type == XML_ATTRIBUTE_NODE) {
            cur = cur->parent;
        } else if (cur->type == XML_NAMESPACE_DECL) {
            xmlNsPtr ns = (xmlNsPtr) cur;
 
            if ((ns->next == NULL) ||
                (ns->next->type == XML_NAMESPACE_DECL))
                return (NULL);
            cur = (xmlNodePtr) ns->next;
        }
        ctxt->ancestor = cur->parent;
    }
    if (cur->type == XML_NAMESPACE_DECL)
        return(NULL);
    if ((cur->prev != NULL) && (cur->prev->type == XML_DTD_NODE))
    cur = cur->prev;
    while (cur->prev == NULL) {
        cur = cur->parent;
        if (cur == NULL)
            return (NULL);
        if (cur == ctxt->context->doc->children)
            return (NULL);
        if (cur != ctxt->ancestor)
            return (cur);
        ctxt->ancestor = cur->parent;
    }
    cur = cur->prev;
    while (cur->last != NULL)
        cur = cur->last;
    return (cur);
}
 
xmlNodePtr
xmlXPathNextNamespace(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (ctxt->context->node->type != XML_ELEMENT_NODE) return(NULL);
    if (cur == NULL) {
        if (ctxt->context->tmpNsList != NULL)
        xmlFree(ctxt->context->tmpNsList);
    ctxt->context->tmpNsList =
        xmlGetNsList(ctxt->context->doc, ctxt->context->node);
    ctxt->context->tmpNsNr = 0;
    if (ctxt->context->tmpNsList != NULL) {
        while (ctxt->context->tmpNsList[ctxt->context->tmpNsNr] != NULL) {
        ctxt->context->tmpNsNr++;
        }
    }
    return((xmlNodePtr) xmlXPathXMLNamespace);
    }
    if (ctxt->context->tmpNsNr > 0) {
    return (xmlNodePtr)ctxt->context->tmpNsList[--ctxt->context->tmpNsNr];
    } else {
    if (ctxt->context->tmpNsList != NULL)
        xmlFree(ctxt->context->tmpNsList);
    ctxt->context->tmpNsList = NULL;
    return(NULL);
    }
}
 
xmlNodePtr
xmlXPathNextAttribute(xmlXPathParserContextPtr ctxt, xmlNodePtr cur) {
    if ((ctxt == NULL) || (ctxt->context == NULL)) return(NULL);
    if (ctxt->context->node == NULL)
    return(NULL);
    if (ctxt->context->node->type != XML_ELEMENT_NODE)
    return(NULL);
    if (cur == NULL) {
        if (ctxt->context->node == (xmlNodePtr) ctxt->context->doc)
        return(NULL);
        return((xmlNodePtr)ctxt->context->node->properties);
    }
    return((xmlNodePtr)cur->next);
}
 
/************************************************************************
 *                                  *
 *      NodeTest Functions                  *
 *                                  *
 ************************************************************************/
 
#define IS_FUNCTION         200
 
 
/************************************************************************
 *                                  *
 *      Implicit tree core function library         *
 *                                  *
 ************************************************************************/
 
void
xmlXPathRoot(xmlXPathParserContextPtr ctxt) {
    if ((ctxt == NULL) || (ctxt->context == NULL))
    return;
    valuePush(ctxt, xmlXPathCacheNewNodeSet(ctxt->context,
    (xmlNodePtr) ctxt->context->doc));
}
 
/************************************************************************
 *                                  *
 *      The explicit core function library          *
 *http://www.w3.org/Style/XSL/Group/1999/07/xpath-19990705.html#corelib *
 *                                  *
 ************************************************************************/
 
 
void
xmlXPathLastFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(0);
    if (ctxt->context->contextSize >= 0) {
    valuePush(ctxt,
        xmlXPathCacheNewFloat(ctxt->context,
        (double) ctxt->context->contextSize));
    } else {
    XP_ERROR(XPATH_INVALID_CTXT_SIZE);
    }
}
 
void
xmlXPathPositionFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(0);
    if (ctxt->context->proximityPosition >= 0) {
    valuePush(ctxt,
          xmlXPathCacheNewFloat(ctxt->context,
        (double) ctxt->context->proximityPosition));
    } else {
    XP_ERROR(XPATH_INVALID_CTXT_POSITION);
    }
}
 
void
xmlXPathCountFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;
 
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_NODESET) &&
     (ctxt->value->type != XPATH_XSLT_TREE)))
    XP_ERROR(XPATH_INVALID_TYPE);
    cur = valuePop(ctxt);
 
    if ((cur == NULL) || (cur->nodesetval == NULL))
    valuePush(ctxt, xmlXPathCacheNewFloat(ctxt->context, (double) 0));
    else
    valuePush(ctxt, xmlXPathCacheNewFloat(ctxt->context,
        (double) cur->nodesetval->nodeNr));
    xmlXPathReleaseObject(ctxt->context, cur);
}
 
static xmlNodeSetPtr
xmlXPathGetElementsByIds (xmlDocPtr doc, const xmlChar *ids) {
    xmlNodeSetPtr ret;
    const xmlChar *cur = ids;
    xmlChar *ID;
    xmlAttrPtr attr;
    xmlNodePtr elem = NULL;
 
    if (ids == NULL) return(NULL);
 
    ret = xmlXPathNodeSetCreate(NULL);
    if (ret == NULL)
        return(ret);
 
    while (IS_BLANK_CH(*cur)) cur++;
    while (*cur != 0) {
    while ((!IS_BLANK_CH(*cur)) && (*cur != 0))
        cur++;
 
        ID = xmlStrndup(ids, cur - ids);
    if (ID != NULL) {
        /*
         * We used to check the fact that the value passed
         * was an NCName, but this generated much troubles for
         * me and Aleksey Sanin, people blatantly violated that
         * constraint, like Visa3D spec.
         * if (xmlValidateNCName(ID, 1) == 0)
         */
        attr = xmlGetID(doc, ID);
        if (attr != NULL) {
        if (attr->type == XML_ATTRIBUTE_NODE)
            elem = attr->parent;
        else if (attr->type == XML_ELEMENT_NODE)
            elem = (xmlNodePtr) attr;
        else
            elem = NULL;
                /* TODO: Check memory error. */
        if (elem != NULL)
            xmlXPathNodeSetAdd(ret, elem);
        }
        xmlFree(ID);
    }
 
    while (IS_BLANK_CH(*cur)) cur++;
    ids = cur;
    }
    return(ret);
}
 
void
xmlXPathIdFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlChar *tokens;
    xmlNodeSetPtr ret;
    xmlXPathObjectPtr obj;
 
    CHECK_ARITY(1);
    obj = valuePop(ctxt);
    if (obj == NULL) XP_ERROR(XPATH_INVALID_OPERAND);
    if ((obj->type == XPATH_NODESET) || (obj->type == XPATH_XSLT_TREE)) {
    xmlNodeSetPtr ns;
    int i;
 
        /* TODO: Check memory error. */
    ret = xmlXPathNodeSetCreate(NULL);
 
    if (obj->nodesetval != NULL) {
        for (i = 0; i < obj->nodesetval->nodeNr; i++) {
        tokens =
            xmlXPathCastNodeToString(obj->nodesetval->nodeTab[i]);
        ns = xmlXPathGetElementsByIds(ctxt->context->doc, tokens);
                /* TODO: Check memory error. */
        ret = xmlXPathNodeSetMerge(ret, ns);
        xmlXPathFreeNodeSet(ns);
        if (tokens != NULL)
            xmlFree(tokens);
        }
    }
    xmlXPathReleaseObject(ctxt->context, obj);
    valuePush(ctxt, xmlXPathCacheWrapNodeSet(ctxt->context, ret));
    return;
    }
    obj = xmlXPathCacheConvertString(ctxt->context, obj);
    if (obj == NULL) return;
    ret = xmlXPathGetElementsByIds(ctxt->context->doc, obj->stringval);
    valuePush(ctxt, xmlXPathCacheWrapNodeSet(ctxt->context, ret));
    xmlXPathReleaseObject(ctxt->context, obj);
    return;
}
 
void
xmlXPathLocalNameFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;
 
    if (ctxt == NULL) return;
 
    if (nargs == 0) {
    valuePush(ctxt, xmlXPathCacheNewNodeSet(ctxt->context,
        ctxt->context->node));
    nargs = 1;
    }
 
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_NODESET) &&
     (ctxt->value->type != XPATH_XSLT_TREE)))
    XP_ERROR(XPATH_INVALID_TYPE);
    cur = valuePop(ctxt);
 
    if ((cur->nodesetval == NULL) || (cur->nodesetval->nodeNr == 0)) {
    valuePush(ctxt, xmlXPathCacheNewCString(ctxt->context, ""));
    } else {
    int i = 0; /* Should be first in document order !!!!! */
    switch (cur->nodesetval->nodeTab[i]->type) {
    case XML_ELEMENT_NODE:
    case XML_ATTRIBUTE_NODE:
    case XML_PI_NODE:
        if (cur->nodesetval->nodeTab[i]->name[0] == ' ')
        valuePush(ctxt, xmlXPathCacheNewCString(ctxt->context, ""));
        else
        valuePush(ctxt,
              xmlXPathCacheNewString(ctxt->context,
            cur->nodesetval->nodeTab[i]->name));
        break;
    case XML_NAMESPACE_DECL:
        valuePush(ctxt, xmlXPathCacheNewString(ctxt->context,
            ((xmlNsPtr)cur->nodesetval->nodeTab[i])->prefix));
        break;
    default:
        valuePush(ctxt, xmlXPathCacheNewCString(ctxt->context, ""));
    }
    }
    xmlXPathReleaseObject(ctxt->context, cur);
}
 
void
xmlXPathNamespaceURIFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;
 
    if (ctxt == NULL) return;
 
    if (nargs == 0) {
    valuePush(ctxt, xmlXPathCacheNewNodeSet(ctxt->context,
        ctxt->context->node));
    nargs = 1;
    }
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_NODESET) &&
     (ctxt->value->type != XPATH_XSLT_TREE)))
    XP_ERROR(XPATH_INVALID_TYPE);
    cur = valuePop(ctxt);
 
    if ((cur->nodesetval == NULL) || (cur->nodesetval->nodeNr == 0)) {
    valuePush(ctxt, xmlXPathCacheNewCString(ctxt->context, ""));
    } else {
    int i = 0; /* Should be first in document order !!!!! */
    switch (cur->nodesetval->nodeTab[i]->type) {
    case XML_ELEMENT_NODE:
    case XML_ATTRIBUTE_NODE:
        if (cur->nodesetval->nodeTab[i]->ns == NULL)
        valuePush(ctxt, xmlXPathCacheNewCString(ctxt->context, ""));
        else
        valuePush(ctxt, xmlXPathCacheNewString(ctxt->context,
              cur->nodesetval->nodeTab[i]->ns->href));
        break;
    default:
        valuePush(ctxt, xmlXPathCacheNewCString(ctxt->context, ""));
    }
    }
    xmlXPathReleaseObject(ctxt->context, cur);
}
 
static void
xmlXPathNameFunction(xmlXPathParserContextPtr ctxt, int nargs)
{
    xmlXPathObjectPtr cur;
 
    if (nargs == 0) {
    valuePush(ctxt, xmlXPathCacheNewNodeSet(ctxt->context,
        ctxt->context->node));
        nargs = 1;
    }
 
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
        ((ctxt->value->type != XPATH_NODESET) &&
         (ctxt->value->type != XPATH_XSLT_TREE)))
        XP_ERROR(XPATH_INVALID_TYPE);
    cur = valuePop(ctxt);
 
    if ((cur->nodesetval == NULL) || (cur->nodesetval->nodeNr == 0)) {
        valuePush(ctxt, xmlXPathCacheNewCString(ctxt->context, ""));
    } else {
        int i = 0;              /* Should be first in document order !!!!! */
 
        switch (cur->nodesetval->nodeTab[i]->type) {
            case XML_ELEMENT_NODE:
            case XML_ATTRIBUTE_NODE:
        if (cur->nodesetval->nodeTab[i]->name[0] == ' ')
            valuePush(ctxt,
            xmlXPathCacheNewCString(ctxt->context, ""));
        else if ((cur->nodesetval->nodeTab[i]->ns == NULL) ||
                         (cur->nodesetval->nodeTab[i]->ns->prefix == NULL)) {
            valuePush(ctxt,
                xmlXPathCacheNewString(ctxt->context,
                cur->nodesetval->nodeTab[i]->name));
        } else {
            xmlChar *fullname;
 
            fullname = xmlBuildQName(cur->nodesetval->nodeTab[i]->name,
                     cur->nodesetval->nodeTab[i]->ns->prefix,
                     NULL, 0);
            if (fullname == cur->nodesetval->nodeTab[i]->name)
            fullname = xmlStrdup(cur->nodesetval->nodeTab[i]->name);
            if (fullname == NULL)
                        xmlXPathPErrMemory(ctxt, NULL);
            valuePush(ctxt, xmlXPathCacheWrapString(
            ctxt->context, fullname));
                }
                break;
            default:
        valuePush(ctxt, xmlXPathCacheNewNodeSet(ctxt->context,
            cur->nodesetval->nodeTab[i]));
                xmlXPathLocalNameFunction(ctxt, 1);
        }
    }
    xmlXPathReleaseObject(ctxt->context, cur);
}
 
 
void
xmlXPathStringFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;
 
    if (ctxt == NULL) return;
    if (nargs == 0) {
    valuePush(ctxt,
    xmlXPathCacheWrapString(ctxt->context,
        xmlXPathCastNodeToString(ctxt->context->node)));
    return;
    }
 
    CHECK_ARITY(1);
    cur = valuePop(ctxt);
    if (cur == NULL) XP_ERROR(XPATH_INVALID_OPERAND);
    valuePush(ctxt, xmlXPathCacheConvertString(ctxt->context, cur));
}
 
void
xmlXPathStringLengthFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;
 
    if (nargs == 0) {
        if ((ctxt == NULL) || (ctxt->context == NULL))
        return;
    if (ctxt->context->node == NULL) {
        valuePush(ctxt, xmlXPathCacheNewFloat(ctxt->context, 0));
    } else {
        xmlChar *content;
 
        content = xmlXPathCastNodeToString(ctxt->context->node);
        valuePush(ctxt, xmlXPathCacheNewFloat(ctxt->context,
        xmlUTF8Strlen(content)));
        xmlFree(content);
    }
    return;
    }
    CHECK_ARITY(1);
    CAST_TO_STRING;
    CHECK_TYPE(XPATH_STRING);
    cur = valuePop(ctxt);
    valuePush(ctxt, xmlXPathCacheNewFloat(ctxt->context,
    xmlUTF8Strlen(cur->stringval)));
    xmlXPathReleaseObject(ctxt->context, cur);
}
 
void
xmlXPathConcatFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur, newobj;
    xmlChar *tmp;
 
    if (ctxt == NULL) return;
    if (nargs < 2) {
    CHECK_ARITY(2);
    }
 
    CAST_TO_STRING;
    cur = valuePop(ctxt);
    if ((cur == NULL) || (cur->type != XPATH_STRING)) {
    xmlXPathReleaseObject(ctxt->context, cur);
    return;
    }
    nargs--;
 
    while (nargs > 0) {
    CAST_TO_STRING;
    newobj = valuePop(ctxt);
    if ((newobj == NULL) || (newobj->type != XPATH_STRING)) {
        xmlXPathReleaseObject(ctxt->context, newobj);
        xmlXPathReleaseObject(ctxt->context, cur);
        XP_ERROR(XPATH_INVALID_TYPE);
    }
    tmp = xmlStrcat(newobj->stringval, cur->stringval);
    newobj->stringval = cur->stringval;
    cur->stringval = tmp;
    xmlXPathReleaseObject(ctxt->context, newobj);
    nargs--;
    }
    valuePush(ctxt, cur);
}
 
void
xmlXPathContainsFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr hay, needle;
 
    CHECK_ARITY(2);
    CAST_TO_STRING;
    CHECK_TYPE(XPATH_STRING);
    needle = valuePop(ctxt);
    CAST_TO_STRING;
    hay = valuePop(ctxt);
 
    if ((hay == NULL) || (hay->type != XPATH_STRING)) {
    xmlXPathReleaseObject(ctxt->context, hay);
    xmlXPathReleaseObject(ctxt->context, needle);
    XP_ERROR(XPATH_INVALID_TYPE);
    }
    if (xmlStrstr(hay->stringval, needle->stringval))
    valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, 1));
    else
    valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, 0));
    xmlXPathReleaseObject(ctxt->context, hay);
    xmlXPathReleaseObject(ctxt->context, needle);
}
 
void
xmlXPathStartsWithFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr hay, needle;
    int n;
 
    CHECK_ARITY(2);
    CAST_TO_STRING;
    CHECK_TYPE(XPATH_STRING);
    needle = valuePop(ctxt);
    CAST_TO_STRING;
    hay = valuePop(ctxt);
 
    if ((hay == NULL) || (hay->type != XPATH_STRING)) {
    xmlXPathReleaseObject(ctxt->context, hay);
    xmlXPathReleaseObject(ctxt->context, needle);
    XP_ERROR(XPATH_INVALID_TYPE);
    }
    n = xmlStrlen(needle->stringval);
    if (xmlStrncmp(hay->stringval, needle->stringval, n))
        valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, 0));
    else
        valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, 1));
    xmlXPathReleaseObject(ctxt->context, hay);
    xmlXPathReleaseObject(ctxt->context, needle);
}
 
void
xmlXPathSubstringFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr str, start, len;
    double le=0, in;
    int i = 1, j = INT_MAX;
 
    if (nargs < 2) {
    CHECK_ARITY(2);
    }
    if (nargs > 3) {
    CHECK_ARITY(3);
    }
    /*
     * take care of possible last (position) argument
    */
    if (nargs == 3) {
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
    len = valuePop(ctxt);
    le = len->floatval;
    xmlXPathReleaseObject(ctxt->context, len);
    }
 
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
    start = valuePop(ctxt);
    in = start->floatval;
    xmlXPathReleaseObject(ctxt->context, start);
    CAST_TO_STRING;
    CHECK_TYPE(XPATH_STRING);
    str = valuePop(ctxt);
 
    if (!(in < INT_MAX)) { /* Logical NOT to handle NaNs */
        i = INT_MAX;
    } else if (in >= 1.0) {
        i = (int)in;
        if (in - floor(in) >= 0.5)
            i += 1;
    }
 
    if (nargs == 3) {
        double rin, rle, end;
 
        rin = floor(in);
        if (in - rin >= 0.5)
            rin += 1.0;
 
        rle = floor(le);
        if (le - rle >= 0.5)
            rle += 1.0;
 
        end = rin + rle;
        if (!(end >= 1.0)) { /* Logical NOT to handle NaNs */
            j = 1;
        } else if (end < INT_MAX) {
            j = (int)end;
        }
    }
 
    if (i < j) {
        xmlChar *ret = xmlUTF8Strsub(str->stringval, i - 1, j - i);
    valuePush(ctxt, xmlXPathCacheNewString(ctxt->context, ret));
    xmlFree(ret);
    } else {
    valuePush(ctxt, xmlXPathCacheNewCString(ctxt->context, ""));
    }
 
    xmlXPathReleaseObject(ctxt->context, str);
}
 
void
xmlXPathSubstringBeforeFunction(xmlXPathParserContextPtr ctxt, int nargs) {
  xmlXPathObjectPtr str;
  xmlXPathObjectPtr find;
  xmlBufPtr target;
  const xmlChar *point;
  int offset;
 
  CHECK_ARITY(2);
  CAST_TO_STRING;
  find = valuePop(ctxt);
  CAST_TO_STRING;
  str = valuePop(ctxt);
 
  target = xmlBufCreate();
  if (target) {
    point = xmlStrstr(str->stringval, find->stringval);
    if (point) {
      offset = point - str->stringval;
      xmlBufAdd(target, str->stringval, offset);
    }
    valuePush(ctxt, xmlXPathCacheNewString(ctxt->context,
    xmlBufContent(target)));
    xmlBufFree(target);
  }
  xmlXPathReleaseObject(ctxt->context, str);
  xmlXPathReleaseObject(ctxt->context, find);
}
 
void
xmlXPathSubstringAfterFunction(xmlXPathParserContextPtr ctxt, int nargs) {
  xmlXPathObjectPtr str;
  xmlXPathObjectPtr find;
  xmlBufPtr target;
  const xmlChar *point;
  int offset;
 
  CHECK_ARITY(2);
  CAST_TO_STRING;
  find = valuePop(ctxt);
  CAST_TO_STRING;
  str = valuePop(ctxt);
 
  target = xmlBufCreate();
  if (target) {
    point = xmlStrstr(str->stringval, find->stringval);
    if (point) {
      offset = point - str->stringval + xmlStrlen(find->stringval);
      xmlBufAdd(target, &str->stringval[offset],
           xmlStrlen(str->stringval) - offset);
    }
    valuePush(ctxt, xmlXPathCacheNewString(ctxt->context,
    xmlBufContent(target)));
    xmlBufFree(target);
  }
  xmlXPathReleaseObject(ctxt->context, str);
  xmlXPathReleaseObject(ctxt->context, find);
}
 
void
xmlXPathNormalizeFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlChar *source, *target;
    int blank;
 
    if (ctxt == NULL) return;
    if (nargs == 0) {
        /* Use current context node */
        valuePush(ctxt,
            xmlXPathCacheWrapString(ctxt->context,
                xmlXPathCastNodeToString(ctxt->context->node)));
        nargs = 1;
    }
 
    CHECK_ARITY(1);
    CAST_TO_STRING;
    CHECK_TYPE(XPATH_STRING);
    source = ctxt->value->stringval;
    if (source == NULL)
        return;
    target = source;
 
    /* Skip leading whitespaces */
    while (IS_BLANK_CH(*source))
        source++;
 
    /* Collapse intermediate whitespaces, and skip trailing whitespaces */
    blank = 0;
    while (*source) {
        if (IS_BLANK_CH(*source)) {
        blank = 1;
        } else {
            if (blank) {
                *target++ = 0x20;
                blank = 0;
            }
            *target++ = *source;
        }
        source++;
    }
    *target = 0;
}
 
void
xmlXPathTranslateFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr str;
    xmlXPathObjectPtr from;
    xmlXPathObjectPtr to;
    xmlBufPtr target;
    int offset, max;
    int ch;
    const xmlChar *point;
    xmlChar *cptr;
 
    CHECK_ARITY(3);
 
    CAST_TO_STRING;
    to = valuePop(ctxt);
    CAST_TO_STRING;
    from = valuePop(ctxt);
    CAST_TO_STRING;
    str = valuePop(ctxt);
 
    target = xmlBufCreate();
    if (target) {
    max = xmlUTF8Strlen(to->stringval);
    for (cptr = str->stringval; (ch=*cptr); ) {
        offset = xmlUTF8Strloc(from->stringval, cptr);
        if (offset >= 0) {
        if (offset < max) {
            point = xmlUTF8Strpos(to->stringval, offset);
            if (point)
            xmlBufAdd(target, point, xmlUTF8Strsize(point, 1));
        }
        } else
        xmlBufAdd(target, cptr, xmlUTF8Strsize(cptr, 1));
 
        /* Step to next character in input */
        cptr++;
        if ( ch & 0x80 ) {
        /* if not simple ascii, verify proper format */
        if ( (ch & 0xc0) != 0xc0 ) {
            xmlGenericError(xmlGenericErrorContext,
            "xmlXPathTranslateFunction: Invalid UTF8 string\n");
                    /* not asserting an XPath error is probably better */
            break;
        }
        /* then skip over remaining bytes for this char */
        while ( (ch <<= 1) & 0x80 )
            if ( (*cptr++ & 0xc0) != 0x80 ) {
            xmlGenericError(xmlGenericErrorContext,
                "xmlXPathTranslateFunction: Invalid UTF8 string\n");
                        /* not asserting an XPath error is probably better */
            break;
            }
        if (ch & 0x80) /* must have had error encountered */
            break;
        }
    }
    }
    valuePush(ctxt, xmlXPathCacheNewString(ctxt->context,
    xmlBufContent(target)));
    xmlBufFree(target);
    xmlXPathReleaseObject(ctxt->context, str);
    xmlXPathReleaseObject(ctxt->context, from);
    xmlXPathReleaseObject(ctxt->context, to);
}
 
void
xmlXPathBooleanFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;
 
    CHECK_ARITY(1);
    cur = valuePop(ctxt);
    if (cur == NULL) XP_ERROR(XPATH_INVALID_OPERAND);
    cur = xmlXPathCacheConvertBoolean(ctxt->context, cur);
    valuePush(ctxt, cur);
}
 
void
xmlXPathNotFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(1);
    CAST_TO_BOOLEAN;
    CHECK_TYPE(XPATH_BOOLEAN);
    ctxt->value->boolval = ! ctxt->value->boolval;
}
 
void
xmlXPathTrueFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(0);
    valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, 1));
}
 
void
xmlXPathFalseFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(0);
    valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, 0));
}
 
void
xmlXPathLangFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr val = NULL;
    const xmlChar *theLang = NULL;
    const xmlChar *lang;
    int ret = 0;
    int i;
 
    CHECK_ARITY(1);
    CAST_TO_STRING;
    CHECK_TYPE(XPATH_STRING);
    val = valuePop(ctxt);
    lang = val->stringval;
    theLang = xmlNodeGetLang(ctxt->context->node);
    if ((theLang != NULL) && (lang != NULL)) {
        for (i = 0;lang[i] != 0;i++)
        if (toupper(lang[i]) != toupper(theLang[i]))
            goto not_equal;
    if ((theLang[i] == 0) || (theLang[i] == '-'))
        ret = 1;
    }
not_equal:
    if (theLang != NULL)
    xmlFree((void *)theLang);
 
    xmlXPathReleaseObject(ctxt->context, val);
    valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, ret));
}
 
void
xmlXPathNumberFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;
    double res;
 
    if (ctxt == NULL) return;
    if (nargs == 0) {
    if (ctxt->context->node == NULL) {
        valuePush(ctxt, xmlXPathCacheNewFloat(ctxt->context, 0.0));
    } else {
        xmlChar* content = xmlNodeGetContent(ctxt->context->node);
 
        res = xmlXPathStringEvalNumber(content);
        valuePush(ctxt, xmlXPathCacheNewFloat(ctxt->context, res));
        xmlFree(content);
    }
    return;
    }
 
    CHECK_ARITY(1);
    cur = valuePop(ctxt);
    valuePush(ctxt, xmlXPathCacheConvertNumber(ctxt->context, cur));
}
 
void
xmlXPathSumFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr cur;
    int i;
    double res = 0.0;
 
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_NODESET) &&
     (ctxt->value->type != XPATH_XSLT_TREE)))
    XP_ERROR(XPATH_INVALID_TYPE);
    cur = valuePop(ctxt);
 
    if ((cur->nodesetval != NULL) && (cur->nodesetval->nodeNr != 0)) {
    for (i = 0; i < cur->nodesetval->nodeNr; i++) {
        res += xmlXPathCastNodeToNumber(cur->nodesetval->nodeTab[i]);
    }
    }
    valuePush(ctxt, xmlXPathCacheNewFloat(ctxt->context, res));
    xmlXPathReleaseObject(ctxt->context, cur);
}
 
void
xmlXPathFloorFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(1);
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
 
    ctxt->value->floatval = floor(ctxt->value->floatval);
}
 
void
xmlXPathCeilingFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(1);
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
 
#ifdef _AIX
    /* Work around buggy ceil() function on AIX */
    ctxt->value->floatval = copysign(ceil(ctxt->value->floatval), ctxt->value->floatval);
#else
    ctxt->value->floatval = ceil(ctxt->value->floatval);
#endif
}
 
void
xmlXPathRoundFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    double f;
 
    CHECK_ARITY(1);
    CAST_TO_NUMBER;
    CHECK_TYPE(XPATH_NUMBER);
 
    f = ctxt->value->floatval;
 
    if ((f >= -0.5) && (f < 0.5)) {
        /* Handles negative zero. */
        ctxt->value->floatval *= 0.0;
    }
    else {
        double rounded = floor(f);
        if (f - rounded >= 0.5)
            rounded += 1.0;
        ctxt->value->floatval = rounded;
    }
}
 
/************************************************************************
 *                                  *
 *          The Parser                  *
 *                                  *
 ************************************************************************/
 
/*
 * a few forward declarations since we use a recursive call based
 * implementation.
 */
static void xmlXPathCompileExpr(xmlXPathParserContextPtr ctxt, int sort);
static void xmlXPathCompPredicate(xmlXPathParserContextPtr ctxt, int filter);
static void xmlXPathCompLocationPath(xmlXPathParserContextPtr ctxt);
static void xmlXPathCompRelativeLocationPath(xmlXPathParserContextPtr ctxt);
static xmlChar * xmlXPathParseNameComplex(xmlXPathParserContextPtr ctxt,
                                      int qualified);
 
static int
xmlXPathCurrentChar(xmlXPathParserContextPtr ctxt, int *len) {
    unsigned char c;
    unsigned int val;
    const xmlChar *cur;
 
    if (ctxt == NULL)
    return(0);
    cur = ctxt->cur;
 
    /*
     * We are supposed to handle UTF8, check it's valid
     * From rfc2044: encoding of the Unicode values on UTF-8:
     *
     * UCS-4 range (hex.)           UTF-8 octet sequence (binary)
     * 0000 0000-0000 007F   0xxxxxxx
     * 0000 0080-0000 07FF   110xxxxx 10xxxxxx
     * 0000 0800-0000 FFFF   1110xxxx 10xxxxxx 10xxxxxx
     *
     * Check for the 0x110000 limit too
     */
    c = *cur;
    if (c & 0x80) {
    if ((cur[1] & 0xc0) != 0x80)
        goto encoding_error;
    if ((c & 0xe0) == 0xe0) {
 
        if ((cur[2] & 0xc0) != 0x80)
        goto encoding_error;
        if ((c & 0xf0) == 0xf0) {
        if (((c & 0xf8) != 0xf0) ||
            ((cur[3] & 0xc0) != 0x80))
            goto encoding_error;
        /* 4-byte code */
        *len = 4;
        val = (cur[0] & 0x7) << 18;
        val |= (cur[1] & 0x3f) << 12;
        val |= (cur[2] & 0x3f) << 6;
        val |= cur[3] & 0x3f;
        } else {
          /* 3-byte code */
        *len = 3;
        val = (cur[0] & 0xf) << 12;
        val |= (cur[1] & 0x3f) << 6;
        val |= cur[2] & 0x3f;
        }
    } else {
      /* 2-byte code */
        *len = 2;
        val = (cur[0] & 0x1f) << 6;
        val |= cur[1] & 0x3f;
    }
    if (!IS_CHAR(val)) {
        XP_ERROR0(XPATH_INVALID_CHAR_ERROR);
    }
    return(val);
    } else {
    /* 1-byte code */
    *len = 1;
    return(*cur);
    }
encoding_error:
    /*
     * If we detect an UTF8 error that probably means that the
     * input encoding didn't get properly advertised in the
     * declaration header. Report the error and switch the encoding
     * to ISO-Latin-1 (if you don't like this policy, just declare the
     * encoding !)
     */
    *len = 0;
    XP_ERROR0(XPATH_ENCODING_ERROR);
}
 
xmlChar *
xmlXPathParseNCName(xmlXPathParserContextPtr ctxt) {
    const xmlChar *in;
    xmlChar *ret;
    int count = 0;
 
    if ((ctxt == NULL) || (ctxt->cur == NULL)) return(NULL);
    /*
     * Accelerator for simple ASCII names
     */
    in = ctxt->cur;
    if (((*in >= 0x61) && (*in <= 0x7A)) ||
    ((*in >= 0x41) && (*in <= 0x5A)) ||
    (*in == '_')) {
    in++;
    while (((*in >= 0x61) && (*in <= 0x7A)) ||
           ((*in >= 0x41) && (*in <= 0x5A)) ||
           ((*in >= 0x30) && (*in <= 0x39)) ||
           (*in == '_') || (*in == '.') ||
           (*in == '-'))
        in++;
    if ((*in == ' ') || (*in == '>') || (*in == '/') ||
            (*in == '[') || (*in == ']') || (*in == ':') ||
            (*in == '@') || (*in == '*')) {
        count = in - ctxt->cur;
        if (count == 0)
        return(NULL);
        ret = xmlStrndup(ctxt->cur, count);
        ctxt->cur = in;
        return(ret);
    }
    }
    return(xmlXPathParseNameComplex(ctxt, 0));
}
 
 
static xmlChar *
xmlXPathParseQName(xmlXPathParserContextPtr ctxt, xmlChar **prefix) {
    xmlChar *ret = NULL;
 
    *prefix = NULL;
    ret = xmlXPathParseNCName(ctxt);
    if (ret && CUR == ':') {
        *prefix = ret;
    NEXT;
    ret = xmlXPathParseNCName(ctxt);
    }
    return(ret);
}
 
xmlChar *
xmlXPathParseName(xmlXPathParserContextPtr ctxt) {
    const xmlChar *in;
    xmlChar *ret;
    size_t count = 0;
 
    if ((ctxt == NULL) || (ctxt->cur == NULL)) return(NULL);
    /*
     * Accelerator for simple ASCII names
     */
    in = ctxt->cur;
    if (((*in >= 0x61) && (*in <= 0x7A)) ||
    ((*in >= 0x41) && (*in <= 0x5A)) ||
    (*in == '_') || (*in == ':')) {
    in++;
    while (((*in >= 0x61) && (*in <= 0x7A)) ||
           ((*in >= 0x41) && (*in <= 0x5A)) ||
           ((*in >= 0x30) && (*in <= 0x39)) ||
           (*in == '_') || (*in == '-') ||
           (*in == ':') || (*in == '.'))
        in++;
    if ((*in > 0) && (*in < 0x80)) {
        count = in - ctxt->cur;
            if (count > XML_MAX_NAME_LENGTH) {
                ctxt->cur = in;
                XP_ERRORNULL(XPATH_EXPR_ERROR);
            }
        ret = xmlStrndup(ctxt->cur, count);
        ctxt->cur = in;
        return(ret);
    }
    }
    return(xmlXPathParseNameComplex(ctxt, 1));
}
 
static xmlChar *
xmlXPathParseNameComplex(xmlXPathParserContextPtr ctxt, int qualified) {
    xmlChar buf[XML_MAX_NAMELEN + 5];
    int len = 0, l;
    int c;
 
    /*
     * Handler for more complex cases
     */
    c = CUR_CHAR(l);
    if ((c == ' ') || (c == '>') || (c == '/') || /* accelerators */
        (c == '[') || (c == ']') || (c == '@') || /* accelerators */
        (c == '*') || /* accelerators */
    (!IS_LETTER(c) && (c != '_') &&
         ((!qualified) || (c != ':')))) {
    return(NULL);
    }
 
    while ((c != ' ') && (c != '>') && (c != '/') && /* test bigname.xml */
       ((IS_LETTER(c)) || (IS_DIGIT(c)) ||
            (c == '.') || (c == '-') ||
        (c == '_') || ((qualified) && (c == ':')) ||
        (IS_COMBINING(c)) ||
        (IS_EXTENDER(c)))) {
    COPY_BUF(l,buf,len,c);
    NEXTL(l);
    c = CUR_CHAR(l);
    if (len >= XML_MAX_NAMELEN) {
        /*
         * Okay someone managed to make a huge name, so he's ready to pay
         * for the processing speed.
         */
        xmlChar *buffer;
        int max = len * 2;
 
            if (len > XML_MAX_NAME_LENGTH) {
                XP_ERRORNULL(XPATH_EXPR_ERROR);
            }
        buffer = (xmlChar *) xmlMallocAtomic(max);
        if (buffer == NULL) {
        XP_ERRORNULL(XPATH_MEMORY_ERROR);
        }
        memcpy(buffer, buf, len);
        while ((IS_LETTER(c)) || (IS_DIGIT(c)) || /* test bigname.xml */
           (c == '.') || (c == '-') ||
           (c == '_') || ((qualified) && (c == ':')) ||
           (IS_COMBINING(c)) ||
           (IS_EXTENDER(c))) {
        if (len + 10 > max) {
                    xmlChar *tmp;
                    if (max > XML_MAX_NAME_LENGTH) {
                        xmlFree(buffer);
                        XP_ERRORNULL(XPATH_EXPR_ERROR);
                    }
            max *= 2;
            tmp = (xmlChar *) xmlRealloc(buffer, max);
            if (tmp == NULL) {
                        xmlFree(buffer);
            XP_ERRORNULL(XPATH_MEMORY_ERROR);
            }
                    buffer = tmp;
        }
        COPY_BUF(l,buffer,len,c);
        NEXTL(l);
        c = CUR_CHAR(l);
        }
        buffer[len] = 0;
        return(buffer);
    }
    }
    if (len == 0)
    return(NULL);
    return(xmlStrndup(buf, len));
}
 
#define MAX_FRAC 20
 
double
xmlXPathStringEvalNumber(const xmlChar *str) {
    const xmlChar *cur = str;
    double ret;
    int ok = 0;
    int isneg = 0;
    int exponent = 0;
    int is_exponent_negative = 0;
#ifdef __GNUC__
    unsigned long tmp = 0;
    double temp;
#endif
    if (cur == NULL) return(0);
    while (IS_BLANK_CH(*cur)) cur++;
    if (*cur == '-') {
    isneg = 1;
    cur++;
    }
    if ((*cur != '.') && ((*cur < '0') || (*cur > '9'))) {
        return(xmlXPathNAN);
    }
 
#ifdef __GNUC__
    /*
     * tmp/temp is a workaround against a gcc compiler bug
     * http://veillard.com/gcc.bug
     */
    ret = 0;
    while ((*cur >= '0') && (*cur <= '9')) {
    ret = ret * 10;
    tmp = (*cur - '0');
    ok = 1;
    cur++;
    temp = (double) tmp;
    ret = ret + temp;
    }
#else
    ret = 0;
    while ((*cur >= '0') && (*cur <= '9')) {
    ret = ret * 10 + (*cur - '0');
    ok = 1;
    cur++;
    }
#endif
 
    if (*cur == '.') {
    int v, frac = 0, max;
    double fraction = 0;
 
        cur++;
    if (((*cur < '0') || (*cur > '9')) && (!ok)) {
        return(xmlXPathNAN);
    }
        while (*cur == '0') {
        frac = frac + 1;
        cur++;
        }
        max = frac + MAX_FRAC;
    while (((*cur >= '0') && (*cur <= '9')) && (frac < max)) {
        v = (*cur - '0');
        fraction = fraction * 10 + v;
        frac = frac + 1;
        cur++;
    }
    fraction /= pow(10.0, frac);
    ret = ret + fraction;
    while ((*cur >= '0') && (*cur <= '9'))
        cur++;
    }
    if ((*cur == 'e') || (*cur == 'E')) {
      cur++;
      if (*cur == '-') {
    is_exponent_negative = 1;
    cur++;
      } else if (*cur == '+') {
        cur++;
      }
      while ((*cur >= '0') && (*cur <= '9')) {
        if (exponent < 1000000)
      exponent = exponent * 10 + (*cur - '0');
    cur++;
      }
    }
    while (IS_BLANK_CH(*cur)) cur++;
    if (*cur != 0) return(xmlXPathNAN);
    if (isneg) ret = -ret;
    if (is_exponent_negative) exponent = -exponent;
    ret *= pow(10.0, (double)exponent);
    return(ret);
}
 
static void
xmlXPathCompNumber(xmlXPathParserContextPtr ctxt)
{
    double ret = 0.0;
    int ok = 0;
    int exponent = 0;
    int is_exponent_negative = 0;
    xmlXPathObjectPtr num;
#ifdef __GNUC__
    unsigned long tmp = 0;
    double temp;
#endif
 
    CHECK_ERROR;
    if ((CUR != '.') && ((CUR < '0') || (CUR > '9'))) {
        XP_ERROR(XPATH_NUMBER_ERROR);
    }
#ifdef __GNUC__
    /*
     * tmp/temp is a workaround against a gcc compiler bug
     * http://veillard.com/gcc.bug
     */
    ret = 0;
    while ((CUR >= '0') && (CUR <= '9')) {
    ret = ret * 10;
    tmp = (CUR - '0');
        ok = 1;
        NEXT;
    temp = (double) tmp;
    ret = ret + temp;
    }
#else
    ret = 0;
    while ((CUR >= '0') && (CUR <= '9')) {
    ret = ret * 10 + (CUR - '0');
    ok = 1;
    NEXT;
    }
#endif
    if (CUR == '.') {
    int v, frac = 0, max;
    double fraction = 0;
 
        NEXT;
        if (((CUR < '0') || (CUR > '9')) && (!ok)) {
            XP_ERROR(XPATH_NUMBER_ERROR);
        }
        while (CUR == '0') {
            frac = frac + 1;
            NEXT;
        }
        max = frac + MAX_FRAC;
        while ((CUR >= '0') && (CUR <= '9') && (frac < max)) {
        v = (CUR - '0');
        fraction = fraction * 10 + v;
        frac = frac + 1;
            NEXT;
        }
        fraction /= pow(10.0, frac);
        ret = ret + fraction;
        while ((CUR >= '0') && (CUR <= '9'))
            NEXT;
    }
    if ((CUR == 'e') || (CUR == 'E')) {
        NEXT;
        if (CUR == '-') {
            is_exponent_negative = 1;
            NEXT;
        } else if (CUR == '+') {
        NEXT;
    }
        while ((CUR >= '0') && (CUR <= '9')) {
            if (exponent < 1000000)
                exponent = exponent * 10 + (CUR - '0');
            NEXT;
        }
        if (is_exponent_negative)
            exponent = -exponent;
        ret *= pow(10.0, (double) exponent);
    }
    num = xmlXPathCacheNewFloat(ctxt->context, ret);
    if (num == NULL) {
    ctxt->error = XPATH_MEMORY_ERROR;
    } else if (PUSH_LONG_EXPR(XPATH_OP_VALUE, XPATH_NUMBER, 0, 0, num,
                              NULL) == -1) {
        xmlXPathReleaseObject(ctxt->context, num);
    }
}
 
static xmlChar *
xmlXPathParseLiteral(xmlXPathParserContextPtr ctxt) {
    const xmlChar *q;
    xmlChar *ret = NULL;
 
    if (CUR == '"') {
        NEXT;
    q = CUR_PTR;
    while ((IS_CHAR_CH(CUR)) && (CUR != '"'))
        NEXT;
    if (!IS_CHAR_CH(CUR)) {
        XP_ERRORNULL(XPATH_UNFINISHED_LITERAL_ERROR);
    } else {
        ret = xmlStrndup(q, CUR_PTR - q);
        NEXT;
        }
    } else if (CUR == '\'') {
        NEXT;
    q = CUR_PTR;
    while ((IS_CHAR_CH(CUR)) && (CUR != '\''))
        NEXT;
    if (!IS_CHAR_CH(CUR)) {
        XP_ERRORNULL(XPATH_UNFINISHED_LITERAL_ERROR);
    } else {
        ret = xmlStrndup(q, CUR_PTR - q);
        NEXT;
        }
    } else {
    XP_ERRORNULL(XPATH_START_LITERAL_ERROR);
    }
    return(ret);
}
 
static void
xmlXPathCompLiteral(xmlXPathParserContextPtr ctxt) {
    const xmlChar *q;
    xmlChar *ret = NULL;
    xmlXPathObjectPtr lit;
 
    if (CUR == '"') {
        NEXT;
    q = CUR_PTR;
    while ((IS_CHAR_CH(CUR)) && (CUR != '"'))
        NEXT;
    if (!IS_CHAR_CH(CUR)) {
        XP_ERROR(XPATH_UNFINISHED_LITERAL_ERROR);
    } else {
        ret = xmlStrndup(q, CUR_PTR - q);
        NEXT;
        }
    } else if (CUR == '\'') {
        NEXT;
    q = CUR_PTR;
    while ((IS_CHAR_CH(CUR)) && (CUR != '\''))
        NEXT;
    if (!IS_CHAR_CH(CUR)) {
        XP_ERROR(XPATH_UNFINISHED_LITERAL_ERROR);
    } else {
        ret = xmlStrndup(q, CUR_PTR - q);
        NEXT;
        }
    } else {
    XP_ERROR(XPATH_START_LITERAL_ERROR);
    }
    if (ret == NULL) {
        xmlXPathPErrMemory(ctxt, NULL);
        return;
    }
    lit = xmlXPathCacheNewString(ctxt->context, ret);
    if (lit == NULL) {
    ctxt->error = XPATH_MEMORY_ERROR;
    } else if (PUSH_LONG_EXPR(XPATH_OP_VALUE, XPATH_STRING, 0, 0, lit,
                              NULL) == -1) {
        xmlXPathReleaseObject(ctxt->context, lit);
    }
    xmlFree(ret);
}
 
static void
xmlXPathCompVariableReference(xmlXPathParserContextPtr ctxt) {
    xmlChar *name;
    xmlChar *prefix;
 
    SKIP_BLANKS;
    if (CUR != '$') {
    XP_ERROR(XPATH_VARIABLE_REF_ERROR);
    }
    NEXT;
    name = xmlXPathParseQName(ctxt, &prefix);
    if (name == NULL) {
        xmlFree(prefix);
    XP_ERROR(XPATH_VARIABLE_REF_ERROR);
    }
    ctxt->comp->last = -1;
    if (PUSH_LONG_EXPR(XPATH_OP_VARIABLE, 0, 0, 0, name, prefix) == -1) {
        xmlFree(prefix);
        xmlFree(name);
    }
    SKIP_BLANKS;
    if ((ctxt->context != NULL) && (ctxt->context->flags & XML_XPATH_NOVAR)) {
    XP_ERROR(XPATH_FORBID_VARIABLE_ERROR);
    }
}
 
int
xmlXPathIsNodeType(const xmlChar *name) {
    if (name == NULL)
    return(0);
 
    if (xmlStrEqual(name, BAD_CAST "node"))
    return(1);
    if (xmlStrEqual(name, BAD_CAST "text"))
    return(1);
    if (xmlStrEqual(name, BAD_CAST "comment"))
    return(1);
    if (xmlStrEqual(name, BAD_CAST "processing-instruction"))
    return(1);
    return(0);
}
 
static void
xmlXPathCompFunctionCall(xmlXPathParserContextPtr ctxt) {
    xmlChar *name;
    xmlChar *prefix;
    int nbargs = 0;
    int sort = 1;
 
    name = xmlXPathParseQName(ctxt, &prefix);
    if (name == NULL) {
    xmlFree(prefix);
    XP_ERROR(XPATH_EXPR_ERROR);
    }
    SKIP_BLANKS;
 
    if (CUR != '(') {
    xmlFree(name);
    xmlFree(prefix);
    XP_ERROR(XPATH_EXPR_ERROR);
    }
    NEXT;
    SKIP_BLANKS;
 
    /*
    * Optimization for count(): we don't need the node-set to be sorted.
    */
    if ((prefix == NULL) && (name[0] == 'c') &&
    xmlStrEqual(name, BAD_CAST "count"))
    {
    sort = 0;
    }
    ctxt->comp->last = -1;
    if (CUR != ')') {
    while (CUR != 0) {
        int op1 = ctxt->comp->last;
        ctxt->comp->last = -1;
        xmlXPathCompileExpr(ctxt, sort);
        if (ctxt->error != XPATH_EXPRESSION_OK) {
        xmlFree(name);
        xmlFree(prefix);
        return;
        }
        PUSH_BINARY_EXPR(XPATH_OP_ARG, op1, ctxt->comp->last, 0, 0);
        nbargs++;
        if (CUR == ')') break;
        if (CUR != ',') {
        xmlFree(name);
        xmlFree(prefix);
        XP_ERROR(XPATH_EXPR_ERROR);
        }
        NEXT;
        SKIP_BLANKS;
    }
    }
    if (PUSH_LONG_EXPR(XPATH_OP_FUNCTION, nbargs, 0, 0, name, prefix) == -1) {
        xmlFree(prefix);
        xmlFree(name);
    }
    NEXT;
    SKIP_BLANKS;
}
 
static void
xmlXPathCompPrimaryExpr(xmlXPathParserContextPtr ctxt) {
    SKIP_BLANKS;
    if (CUR == '$') xmlXPathCompVariableReference(ctxt);
    else if (CUR == '(') {
    NEXT;
    SKIP_BLANKS;
    xmlXPathCompileExpr(ctxt, 1);
    CHECK_ERROR;
    if (CUR != ')') {
        XP_ERROR(XPATH_EXPR_ERROR);
    }
    NEXT;
    SKIP_BLANKS;
    } else if (IS_ASCII_DIGIT(CUR) || (CUR == '.' && IS_ASCII_DIGIT(NXT(1)))) {
    xmlXPathCompNumber(ctxt);
    } else if ((CUR == '\'') || (CUR == '"')) {
    xmlXPathCompLiteral(ctxt);
    } else {
    xmlXPathCompFunctionCall(ctxt);
    }
    SKIP_BLANKS;
}
 
static void
xmlXPathCompFilterExpr(xmlXPathParserContextPtr ctxt) {
    xmlXPathCompPrimaryExpr(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
 
    while (CUR == '[') {
    xmlXPathCompPredicate(ctxt, 1);
    SKIP_BLANKS;
    }
 
 
}
 
static xmlChar *
xmlXPathScanName(xmlXPathParserContextPtr ctxt) {
    int l;
    int c;
    const xmlChar *cur;
    xmlChar *ret;
 
    cur = ctxt->cur;
 
    c = CUR_CHAR(l);
    if ((c == ' ') || (c == '>') || (c == '/') || /* accelerators */
    (!IS_LETTER(c) && (c != '_') &&
         (c != ':'))) {
    return(NULL);
    }
 
    while ((c != ' ') && (c != '>') && (c != '/') && /* test bigname.xml */
       ((IS_LETTER(c)) || (IS_DIGIT(c)) ||
            (c == '.') || (c == '-') ||
        (c == '_') || (c == ':') ||
        (IS_COMBINING(c)) ||
        (IS_EXTENDER(c)))) {
    NEXTL(l);
    c = CUR_CHAR(l);
    }
    ret = xmlStrndup(cur, ctxt->cur - cur);
    ctxt->cur = cur;
    return(ret);
}
 
static void
xmlXPathCompPathExpr(xmlXPathParserContextPtr ctxt) {
    int lc = 1;           /* Should we branch to LocationPath ?         */
    xmlChar *name = NULL; /* we may have to preparse a name to find out */
 
    SKIP_BLANKS;
    if ((CUR == '$') || (CUR == '(') ||
    (IS_ASCII_DIGIT(CUR)) ||
        (CUR == '\'') || (CUR == '"') ||
    (CUR == '.' && IS_ASCII_DIGIT(NXT(1)))) {
    lc = 0;
    } else if (CUR == '*') {
    /* relative or absolute location path */
    lc = 1;
    } else if (CUR == '/') {
    /* relative or absolute location path */
    lc = 1;
    } else if (CUR == '@') {
    /* relative abbreviated attribute location path */
    lc = 1;
    } else if (CUR == '.') {
    /* relative abbreviated attribute location path */
    lc = 1;
    } else {
    /*
     * Problem is finding if we have a name here whether it's:
     *   - a nodetype
     *   - a function call in which case it's followed by '('
     *   - an axis in which case it's followed by ':'
     *   - a element name
     * We do an a priori analysis here rather than having to
     * maintain parsed token content through the recursive function
     * calls. This looks uglier but makes the code easier to
     * read/write/debug.
     */
    SKIP_BLANKS;
    name = xmlXPathScanName(ctxt);
    if ((name != NULL) && (xmlStrstr(name, (xmlChar *) "::") != NULL)) {
        lc = 1;
        xmlFree(name);
    } else if (name != NULL) {
        int len =xmlStrlen(name);
 
 
        while (NXT(len) != 0) {
        if (NXT(len) == '/') {
            /* element name */
            lc = 1;
            break;
        } else if (IS_BLANK_CH(NXT(len))) {
            /* ignore blanks */
            ;
        } else if (NXT(len) == ':') {
            lc = 1;
            break;
        } else if ((NXT(len) == '(')) {
            /* Node Type or Function */
            if (xmlXPathIsNodeType(name)) {
            lc = 1;
#ifdef LIBXML_XPTR_LOCS_ENABLED
                    } else if (ctxt->xptr &&
                               xmlStrEqual(name, BAD_CAST "range-to")) {
                        lc = 1;
#endif
            } else {
            lc = 0;
            }
                    break;
        } else if ((NXT(len) == '[')) {
            /* element name */
            lc = 1;
            break;
        } else if ((NXT(len) == '<') || (NXT(len) == '>') ||
               (NXT(len) == '=')) {
            lc = 1;
            break;
        } else {
            lc = 1;
            break;
        }
        len++;
        }
        if (NXT(len) == 0) {
        /* element name */
        lc = 1;
        }
        xmlFree(name);
    } else {
        /* make sure all cases are covered explicitly */
        XP_ERROR(XPATH_EXPR_ERROR);
    }
    }
 
    if (lc) {
    if (CUR == '/') {
        PUSH_LEAVE_EXPR(XPATH_OP_ROOT, 0, 0);
    } else {
        PUSH_LEAVE_EXPR(XPATH_OP_NODE, 0, 0);
    }
    xmlXPathCompLocationPath(ctxt);
    } else {
    xmlXPathCompFilterExpr(ctxt);
    CHECK_ERROR;
    if ((CUR == '/') && (NXT(1) == '/')) {
        SKIP(2);
        SKIP_BLANKS;
 
        PUSH_LONG_EXPR(XPATH_OP_COLLECT, AXIS_DESCENDANT_OR_SELF,
            NODE_TEST_TYPE, NODE_TYPE_NODE, NULL, NULL);
 
        xmlXPathCompRelativeLocationPath(ctxt);
    } else if (CUR == '/') {
        xmlXPathCompRelativeLocationPath(ctxt);
    }
    }
    SKIP_BLANKS;
}
 
static void
xmlXPathCompUnionExpr(xmlXPathParserContextPtr ctxt) {
    xmlXPathCompPathExpr(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
    while (CUR == '|') {
    int op1 = ctxt->comp->last;
    PUSH_LEAVE_EXPR(XPATH_OP_NODE, 0, 0);
 
    NEXT;
    SKIP_BLANKS;
    xmlXPathCompPathExpr(ctxt);
 
    PUSH_BINARY_EXPR(XPATH_OP_UNION, op1, ctxt->comp->last, 0, 0);
 
    SKIP_BLANKS;
    }
}
 
static void
xmlXPathCompUnaryExpr(xmlXPathParserContextPtr ctxt) {
    int minus = 0;
    int found = 0;
 
    SKIP_BLANKS;
    while (CUR == '-') {
        minus = 1 - minus;
    found = 1;
    NEXT;
    SKIP_BLANKS;
    }
 
    xmlXPathCompUnionExpr(ctxt);
    CHECK_ERROR;
    if (found) {
    if (minus)
        PUSH_UNARY_EXPR(XPATH_OP_PLUS, ctxt->comp->last, 2, 0);
    else
        PUSH_UNARY_EXPR(XPATH_OP_PLUS, ctxt->comp->last, 3, 0);
    }
}
 
static void
xmlXPathCompMultiplicativeExpr(xmlXPathParserContextPtr ctxt) {
    xmlXPathCompUnaryExpr(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
    while ((CUR == '*') ||
           ((CUR == 'd') && (NXT(1) == 'i') && (NXT(2) == 'v')) ||
           ((CUR == 'm') && (NXT(1) == 'o') && (NXT(2) == 'd'))) {
    int op = -1;
    int op1 = ctxt->comp->last;
 
        if (CUR == '*') {
        op = 0;
        NEXT;
    } else if (CUR == 'd') {
        op = 1;
        SKIP(3);
    } else if (CUR == 'm') {
        op = 2;
        SKIP(3);
    }
    SKIP_BLANKS;
        xmlXPathCompUnaryExpr(ctxt);
    CHECK_ERROR;
    PUSH_BINARY_EXPR(XPATH_OP_MULT, op1, ctxt->comp->last, op, 0);
    SKIP_BLANKS;
    }
}
 
static void
xmlXPathCompAdditiveExpr(xmlXPathParserContextPtr ctxt) {
 
    xmlXPathCompMultiplicativeExpr(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
    while ((CUR == '+') || (CUR == '-')) {
    int plus;
    int op1 = ctxt->comp->last;
 
        if (CUR == '+') plus = 1;
    else plus = 0;
    NEXT;
    SKIP_BLANKS;
        xmlXPathCompMultiplicativeExpr(ctxt);
    CHECK_ERROR;
    PUSH_BINARY_EXPR(XPATH_OP_PLUS, op1, ctxt->comp->last, plus, 0);
    SKIP_BLANKS;
    }
}
 
static void
xmlXPathCompRelationalExpr(xmlXPathParserContextPtr ctxt) {
    xmlXPathCompAdditiveExpr(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
    while ((CUR == '<') || (CUR == '>')) {
    int inf, strict;
    int op1 = ctxt->comp->last;
 
        if (CUR == '<') inf = 1;
    else inf = 0;
    if (NXT(1) == '=') strict = 0;
    else strict = 1;
    NEXT;
    if (!strict) NEXT;
    SKIP_BLANKS;
        xmlXPathCompAdditiveExpr(ctxt);
    CHECK_ERROR;
    PUSH_BINARY_EXPR(XPATH_OP_CMP, op1, ctxt->comp->last, inf, strict);
    SKIP_BLANKS;
    }
}
 
static void
xmlXPathCompEqualityExpr(xmlXPathParserContextPtr ctxt) {
    xmlXPathCompRelationalExpr(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
    while ((CUR == '=') || ((CUR == '!') && (NXT(1) == '='))) {
    int eq;
    int op1 = ctxt->comp->last;
 
        if (CUR == '=') eq = 1;
    else eq = 0;
    NEXT;
    if (!eq) NEXT;
    SKIP_BLANKS;
        xmlXPathCompRelationalExpr(ctxt);
    CHECK_ERROR;
    PUSH_BINARY_EXPR(XPATH_OP_EQUAL, op1, ctxt->comp->last, eq, 0);
    SKIP_BLANKS;
    }
}
 
static void
xmlXPathCompAndExpr(xmlXPathParserContextPtr ctxt) {
    xmlXPathCompEqualityExpr(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
    while ((CUR == 'a') && (NXT(1) == 'n') && (NXT(2) == 'd')) {
    int op1 = ctxt->comp->last;
        SKIP(3);
    SKIP_BLANKS;
        xmlXPathCompEqualityExpr(ctxt);
    CHECK_ERROR;
    PUSH_BINARY_EXPR(XPATH_OP_AND, op1, ctxt->comp->last, 0, 0);
    SKIP_BLANKS;
    }
}
 
static void
xmlXPathCompileExpr(xmlXPathParserContextPtr ctxt, int sort) {
    xmlXPathContextPtr xpctxt = ctxt->context;
 
    if (xpctxt != NULL) {
        if (xpctxt->depth >= XPATH_MAX_RECURSION_DEPTH)
            XP_ERROR(XPATH_RECURSION_LIMIT_EXCEEDED);
        /*
         * Parsing a single '(' pushes about 10 functions on the call stack
         * before recursing!
         */
        xpctxt->depth += 10;
    }
 
    xmlXPathCompAndExpr(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
    while ((CUR == 'o') && (NXT(1) == 'r')) {
    int op1 = ctxt->comp->last;
        SKIP(2);
    SKIP_BLANKS;
        xmlXPathCompAndExpr(ctxt);
    CHECK_ERROR;
    PUSH_BINARY_EXPR(XPATH_OP_OR, op1, ctxt->comp->last, 0, 0);
    SKIP_BLANKS;
    }
    if ((sort) && (ctxt->comp->steps[ctxt->comp->last].op != XPATH_OP_VALUE)) {
    /* more ops could be optimized too */
    /*
    * This is the main place to eliminate sorting for
    * operations which don't require a sorted node-set.
    * E.g. count().
    */
    PUSH_UNARY_EXPR(XPATH_OP_SORT, ctxt->comp->last , 0, 0);
    }
 
    if (xpctxt != NULL)
        xpctxt->depth -= 10;
}
 
static void
xmlXPathCompPredicate(xmlXPathParserContextPtr ctxt, int filter) {
    int op1 = ctxt->comp->last;
 
    SKIP_BLANKS;
    if (CUR != '[') {
    XP_ERROR(XPATH_INVALID_PREDICATE_ERROR);
    }
    NEXT;
    SKIP_BLANKS;
 
    ctxt->comp->last = -1;
    /*
    * This call to xmlXPathCompileExpr() will deactivate sorting
    * of the predicate result.
    * TODO: Sorting is still activated for filters, since I'm not
    *  sure if needed. Normally sorting should not be needed, since
    *  a filter can only diminish the number of items in a sequence,
    *  but won't change its order; so if the initial sequence is sorted,
    *  subsequent sorting is not needed.
    */
    if (! filter)
    xmlXPathCompileExpr(ctxt, 0);
    else
    xmlXPathCompileExpr(ctxt, 1);
    CHECK_ERROR;
 
    if (CUR != ']') {
    XP_ERROR(XPATH_INVALID_PREDICATE_ERROR);
    }
 
    if (filter)
    PUSH_BINARY_EXPR(XPATH_OP_FILTER, op1, ctxt->comp->last, 0, 0);
    else
    PUSH_BINARY_EXPR(XPATH_OP_PREDICATE, op1, ctxt->comp->last, 0, 0);
 
    NEXT;
    SKIP_BLANKS;
}
 
static xmlChar *
xmlXPathCompNodeTest(xmlXPathParserContextPtr ctxt, xmlXPathTestVal *test,
                 xmlXPathTypeVal *type, xmlChar **prefix,
             xmlChar *name) {
    int blanks;
 
    if ((test == NULL) || (type == NULL) || (prefix == NULL)) {
    STRANGE;
    return(NULL);
    }
    *type = (xmlXPathTypeVal) 0;
    *test = (xmlXPathTestVal) 0;
    *prefix = NULL;
    SKIP_BLANKS;
 
    if ((name == NULL) && (CUR == '*')) {
    /*
     * All elements
     */
    NEXT;
    *test = NODE_TEST_ALL;
    return(NULL);
    }
 
    if (name == NULL)
    name = xmlXPathParseNCName(ctxt);
    if (name == NULL) {
    XP_ERRORNULL(XPATH_EXPR_ERROR);
    }
 
    blanks = IS_BLANK_CH(CUR);
    SKIP_BLANKS;
    if (CUR == '(') {
    NEXT;
    /*
     * NodeType or PI search
     */
    if (xmlStrEqual(name, BAD_CAST "comment"))
        *type = NODE_TYPE_COMMENT;
    else if (xmlStrEqual(name, BAD_CAST "node"))
        *type = NODE_TYPE_NODE;
    else if (xmlStrEqual(name, BAD_CAST "processing-instruction"))
        *type = NODE_TYPE_PI;
    else if (xmlStrEqual(name, BAD_CAST "text"))
        *type = NODE_TYPE_TEXT;
    else {
        if (name != NULL)
        xmlFree(name);
        XP_ERRORNULL(XPATH_EXPR_ERROR);
    }
 
    *test = NODE_TEST_TYPE;
 
    SKIP_BLANKS;
    if (*type == NODE_TYPE_PI) {
        /*
         * Specific case: search a PI by name.
         */
        if (name != NULL)
        xmlFree(name);
        name = NULL;
        if (CUR != ')') {
        name = xmlXPathParseLiteral(ctxt);
                if (name == NULL) {
                XP_ERRORNULL(XPATH_EXPR_ERROR);
                }
        *test = NODE_TEST_PI;
        SKIP_BLANKS;
        }
    }
    if (CUR != ')') {
        if (name != NULL)
        xmlFree(name);
        XP_ERRORNULL(XPATH_UNCLOSED_ERROR);
    }
    NEXT;
    return(name);
    }
    *test = NODE_TEST_NAME;
    if ((!blanks) && (CUR == ':')) {
    NEXT;
 
    /*
     * Since currently the parser context don't have a
     * namespace list associated:
     * The namespace name for this prefix can be computed
     * only at evaluation time. The compilation is done
     * outside of any context.
     */
#if 0
    *prefix = xmlXPathNsLookup(ctxt->context, name);
    if (name != NULL)
        xmlFree(name);
    if (*prefix == NULL) {
        XP_ERROR0(XPATH_UNDEF_PREFIX_ERROR);
    }
#else
    *prefix = name;
#endif
 
    if (CUR == '*') {
        /*
         * All elements
         */
        NEXT;
        *test = NODE_TEST_ALL;
        return(NULL);
    }
 
    name = xmlXPathParseNCName(ctxt);
    if (name == NULL) {
        XP_ERRORNULL(XPATH_EXPR_ERROR);
    }
    }
    return(name);
}
 
static xmlXPathAxisVal
xmlXPathIsAxisName(const xmlChar *name) {
    xmlXPathAxisVal ret = (xmlXPathAxisVal) 0;
    switch (name[0]) {
    case 'a':
        if (xmlStrEqual(name, BAD_CAST "ancestor"))
        ret = AXIS_ANCESTOR;
        if (xmlStrEqual(name, BAD_CAST "ancestor-or-self"))
        ret = AXIS_ANCESTOR_OR_SELF;
        if (xmlStrEqual(name, BAD_CAST "attribute"))
        ret = AXIS_ATTRIBUTE;
        break;
    case 'c':
        if (xmlStrEqual(name, BAD_CAST "child"))
        ret = AXIS_CHILD;
        break;
    case 'd':
        if (xmlStrEqual(name, BAD_CAST "descendant"))
        ret = AXIS_DESCENDANT;
        if (xmlStrEqual(name, BAD_CAST "descendant-or-self"))
        ret = AXIS_DESCENDANT_OR_SELF;
        break;
    case 'f':
        if (xmlStrEqual(name, BAD_CAST "following"))
        ret = AXIS_FOLLOWING;
        if (xmlStrEqual(name, BAD_CAST "following-sibling"))
        ret = AXIS_FOLLOWING_SIBLING;
        break;
    case 'n':
        if (xmlStrEqual(name, BAD_CAST "namespace"))
        ret = AXIS_NAMESPACE;
        break;
    case 'p':
        if (xmlStrEqual(name, BAD_CAST "parent"))
        ret = AXIS_PARENT;
        if (xmlStrEqual(name, BAD_CAST "preceding"))
        ret = AXIS_PRECEDING;
        if (xmlStrEqual(name, BAD_CAST "preceding-sibling"))
        ret = AXIS_PRECEDING_SIBLING;
        break;
    case 's':
        if (xmlStrEqual(name, BAD_CAST "self"))
        ret = AXIS_SELF;
        break;
    }
    return(ret);
}
 
static void
xmlXPathCompStep(xmlXPathParserContextPtr ctxt) {
#ifdef LIBXML_XPTR_LOCS_ENABLED
    int rangeto = 0;
    int op2 = -1;
#endif
 
    SKIP_BLANKS;
    if ((CUR == '.') && (NXT(1) == '.')) {
    SKIP(2);
    SKIP_BLANKS;
    PUSH_LONG_EXPR(XPATH_OP_COLLECT, AXIS_PARENT,
            NODE_TEST_TYPE, NODE_TYPE_NODE, NULL, NULL);
    } else if (CUR == '.') {
    NEXT;
    SKIP_BLANKS;
    } else {
    xmlChar *name = NULL;
    xmlChar *prefix = NULL;
    xmlXPathTestVal test = (xmlXPathTestVal) 0;
    xmlXPathAxisVal axis = (xmlXPathAxisVal) 0;
    xmlXPathTypeVal type = (xmlXPathTypeVal) 0;
    int op1;
 
    /*
     * The modification needed for XPointer change to the production
     */
#ifdef LIBXML_XPTR_LOCS_ENABLED
    if (ctxt->xptr) {
        name = xmlXPathParseNCName(ctxt);
        if ((name != NULL) && (xmlStrEqual(name, BAD_CAST "range-to"))) {
                op2 = ctxt->comp->last;
        xmlFree(name);
        SKIP_BLANKS;
        if (CUR != '(') {
            XP_ERROR(XPATH_EXPR_ERROR);
        }
        NEXT;
        SKIP_BLANKS;
 
        xmlXPathCompileExpr(ctxt, 1);
        /* PUSH_BINARY_EXPR(XPATH_OP_RANGETO, op2, ctxt->comp->last, 0, 0); */
        CHECK_ERROR;
 
        SKIP_BLANKS;
        if (CUR != ')') {
            XP_ERROR(XPATH_EXPR_ERROR);
        }
        NEXT;
        rangeto = 1;
        goto eval_predicates;
        }
    }
#endif
    if (CUR == '*') {
        axis = AXIS_CHILD;
    } else {
        if (name == NULL)
        name = xmlXPathParseNCName(ctxt);
        if (name != NULL) {
        axis = xmlXPathIsAxisName(name);
        if (axis != 0) {
            SKIP_BLANKS;
            if ((CUR == ':') && (NXT(1) == ':')) {
            SKIP(2);
            xmlFree(name);
            name = NULL;
            } else {
            /* an element name can conflict with an axis one :-\ */
            axis = AXIS_CHILD;
            }
        } else {
            axis = AXIS_CHILD;
        }
        } else if (CUR == '@') {
        NEXT;
        axis = AXIS_ATTRIBUTE;
        } else {
        axis = AXIS_CHILD;
        }
    }
 
        if (ctxt->error != XPATH_EXPRESSION_OK) {
            xmlFree(name);
            return;
        }
 
    name = xmlXPathCompNodeTest(ctxt, &test, &type, &prefix, name);
    if (test == 0)
        return;
 
        if ((prefix != NULL) && (ctxt->context != NULL) &&
        (ctxt->context->flags & XML_XPATH_CHECKNS)) {
        if (xmlXPathNsLookup(ctxt->context, prefix) == NULL) {
        xmlXPathErr(ctxt, XPATH_UNDEF_PREFIX_ERROR);
        }
    }
 
#ifdef LIBXML_XPTR_LOCS_ENABLED
eval_predicates:
#endif
    op1 = ctxt->comp->last;
    ctxt->comp->last = -1;
 
    SKIP_BLANKS;
    while (CUR == '[') {
        xmlXPathCompPredicate(ctxt, 0);
    }
 
#ifdef LIBXML_XPTR_LOCS_ENABLED
    if (rangeto) {
        PUSH_BINARY_EXPR(XPATH_OP_RANGETO, op2, op1, 0, 0);
    } else
#endif
        if (PUSH_FULL_EXPR(XPATH_OP_COLLECT, op1, ctxt->comp->last, axis,
                           test, type, (void *)prefix, (void *)name) == -1) {
            xmlFree(prefix);
            xmlFree(name);
        }
    }
}
 
static void
xmlXPathCompRelativeLocationPath
(xmlXPathParserContextPtr ctxt) {
    SKIP_BLANKS;
    if ((CUR == '/') && (NXT(1) == '/')) {
    SKIP(2);
    SKIP_BLANKS;
    PUSH_LONG_EXPR(XPATH_OP_COLLECT, AXIS_DESCENDANT_OR_SELF,
                 NODE_TEST_TYPE, NODE_TYPE_NODE, NULL, NULL);
    } else if (CUR == '/') {
        NEXT;
    SKIP_BLANKS;
    }
    xmlXPathCompStep(ctxt);
    CHECK_ERROR;
    SKIP_BLANKS;
    while (CUR == '/') {
    if ((CUR == '/') && (NXT(1) == '/')) {
        SKIP(2);
        SKIP_BLANKS;
        PUSH_LONG_EXPR(XPATH_OP_COLLECT, AXIS_DESCENDANT_OR_SELF,
                 NODE_TEST_TYPE, NODE_TYPE_NODE, NULL, NULL);
        xmlXPathCompStep(ctxt);
    } else if (CUR == '/') {
        NEXT;
        SKIP_BLANKS;
        xmlXPathCompStep(ctxt);
    }
    SKIP_BLANKS;
    }
}
 
static void
xmlXPathCompLocationPath(xmlXPathParserContextPtr ctxt) {
    SKIP_BLANKS;
    if (CUR != '/') {
        xmlXPathCompRelativeLocationPath(ctxt);
    } else {
    while (CUR == '/') {
        if ((CUR == '/') && (NXT(1) == '/')) {
        SKIP(2);
        SKIP_BLANKS;
        PUSH_LONG_EXPR(XPATH_OP_COLLECT, AXIS_DESCENDANT_OR_SELF,
                 NODE_TEST_TYPE, NODE_TYPE_NODE, NULL, NULL);
        xmlXPathCompRelativeLocationPath(ctxt);
        } else if (CUR == '/') {
        NEXT;
        SKIP_BLANKS;
        if ((CUR != 0 ) &&
            ((IS_ASCII_LETTER(CUR)) || (CUR == '_') || (CUR == '.') ||
             (CUR == '@') || (CUR == '*')))
            xmlXPathCompRelativeLocationPath(ctxt);
        }
        CHECK_ERROR;
    }
    }
}
 
/************************************************************************
 *                                  *
 *      XPath precompiled expression evaluation         *
 *                                  *
 ************************************************************************/
 
static int
xmlXPathCompOpEval(xmlXPathParserContextPtr ctxt, xmlXPathStepOpPtr op);
 
static void
xmlXPathNodeSetFilter(xmlXPathParserContextPtr ctxt,
              xmlNodeSetPtr set,
              int filterOpIndex,
                      int minPos, int maxPos,
              int hasNsNodes)
{
    xmlXPathContextPtr xpctxt;
    xmlNodePtr oldnode;
    xmlDocPtr olddoc;
    xmlXPathStepOpPtr filterOp;
    int oldcs, oldpp;
    int i, j, pos;
 
    if ((set == NULL) || (set->nodeNr == 0))
        return;
 
    /*
    * Check if the node set contains a sufficient number of nodes for
    * the requested range.
    */
    if (set->nodeNr < minPos) {
        xmlXPathNodeSetClear(set, hasNsNodes);
        return;
    }
 
    xpctxt = ctxt->context;
    oldnode = xpctxt->node;
    olddoc = xpctxt->doc;
    oldcs = xpctxt->contextSize;
    oldpp = xpctxt->proximityPosition;
    filterOp = &ctxt->comp->steps[filterOpIndex];
 
    xpctxt->contextSize = set->nodeNr;
 
    for (i = 0, j = 0, pos = 1; i < set->nodeNr; i++) {
        xmlNodePtr node = set->nodeTab[i];
        int res;
 
        xpctxt->node = node;
        xpctxt->proximityPosition = i + 1;
 
        /*
        * Also set the xpath document in case things like
        * key() are evaluated in the predicate.
        *
        * TODO: Get real doc for namespace nodes.
        */
        if ((node->type != XML_NAMESPACE_DECL) &&
            (node->doc != NULL))
            xpctxt->doc = node->doc;
 
        res = xmlXPathCompOpEvalToBoolean(ctxt, filterOp, 1);
 
        if (ctxt->error != XPATH_EXPRESSION_OK)
            break;
        if (res < 0) {
            /* Shouldn't happen */
            xmlXPathErr(ctxt, XPATH_EXPR_ERROR);
            break;
        }
 
        if ((res != 0) && ((pos >= minPos) && (pos <= maxPos))) {
            if (i != j) {
                set->nodeTab[j] = node;
                set->nodeTab[i] = NULL;
            }
 
            j += 1;
        } else {
            /* Remove the entry from the initial node set. */
            set->nodeTab[i] = NULL;
            if (node->type == XML_NAMESPACE_DECL)
                xmlXPathNodeSetFreeNs((xmlNsPtr) node);
        }
 
        if (res != 0) {
            if (pos == maxPos) {
                i += 1;
                break;
            }
 
            pos += 1;
        }
    }
 
    /* Free remaining nodes. */
    if (hasNsNodes) {
        for (; i < set->nodeNr; i++) {
            xmlNodePtr node = set->nodeTab[i];
            if ((node != NULL) && (node->type == XML_NAMESPACE_DECL))
                xmlXPathNodeSetFreeNs((xmlNsPtr) node);
        }
    }
 
    set->nodeNr = j;
 
    /* If too many elements were removed, shrink table to preserve memory. */
    if ((set->nodeMax > XML_NODESET_DEFAULT) &&
        (set->nodeNr < set->nodeMax / 2)) {
        xmlNodePtr *tmp;
        int nodeMax = set->nodeNr;
 
        if (nodeMax < XML_NODESET_DEFAULT)
            nodeMax = XML_NODESET_DEFAULT;
        tmp = (xmlNodePtr *) xmlRealloc(set->nodeTab,
                nodeMax * sizeof(xmlNodePtr));
        if (tmp == NULL) {
            xmlXPathPErrMemory(ctxt, "shrinking nodeset\n");
        } else {
            set->nodeTab = tmp;
            set->nodeMax = nodeMax;
        }
    }
 
    xpctxt->node = oldnode;
    xpctxt->doc = olddoc;
    xpctxt->contextSize = oldcs;
    xpctxt->proximityPosition = oldpp;
}
 
#ifdef LIBXML_XPTR_LOCS_ENABLED
static void
xmlXPathLocationSetFilter(xmlXPathParserContextPtr ctxt,
                  xmlLocationSetPtr locset,
                  int filterOpIndex,
                          int minPos, int maxPos)
{
    xmlXPathContextPtr xpctxt;
    xmlNodePtr oldnode;
    xmlDocPtr olddoc;
    xmlXPathStepOpPtr filterOp;
    int oldcs, oldpp;
    int i, j, pos;
 
    if ((locset == NULL) || (locset->locNr == 0) || (filterOpIndex == -1))
        return;
 
    xpctxt = ctxt->context;
    oldnode = xpctxt->node;
    olddoc = xpctxt->doc;
    oldcs = xpctxt->contextSize;
    oldpp = xpctxt->proximityPosition;
    filterOp = &ctxt->comp->steps[filterOpIndex];
 
    xpctxt->contextSize = locset->locNr;
 
    for (i = 0, j = 0, pos = 1; i < locset->locNr; i++) {
        xmlNodePtr contextNode = locset->locTab[i]->user;
        int res;
 
        xpctxt->node = contextNode;
        xpctxt->proximityPosition = i + 1;
 
        /*
        * Also set the xpath document in case things like
        * key() are evaluated in the predicate.
        *
        * TODO: Get real doc for namespace nodes.
        */
        if ((contextNode->type != XML_NAMESPACE_DECL) &&
            (contextNode->doc != NULL))
            xpctxt->doc = contextNode->doc;
 
        res = xmlXPathCompOpEvalToBoolean(ctxt, filterOp, 1);
 
        if (ctxt->error != XPATH_EXPRESSION_OK)
            break;
        if (res < 0) {
            /* Shouldn't happen */
            xmlXPathErr(ctxt, XPATH_EXPR_ERROR);
            break;
        }
 
        if ((res != 0) && ((pos >= minPos) && (pos <= maxPos))) {
            if (i != j) {
                locset->locTab[j] = locset->locTab[i];
                locset->locTab[i] = NULL;
            }
 
            j += 1;
        } else {
            /* Remove the entry from the initial location set. */
            xmlXPathFreeObject(locset->locTab[i]);
            locset->locTab[i] = NULL;
        }
 
        if (res != 0) {
            if (pos == maxPos) {
                i += 1;
                break;
            }
 
            pos += 1;
        }
    }
 
    /* Free remaining nodes. */
    for (; i < locset->locNr; i++)
        xmlXPathFreeObject(locset->locTab[i]);
 
    locset->locNr = j;
 
    /* If too many elements were removed, shrink table to preserve memory. */
    if ((locset->locMax > XML_NODESET_DEFAULT) &&
        (locset->locNr < locset->locMax / 2)) {
        xmlXPathObjectPtr *tmp;
        int locMax = locset->locNr;
 
        if (locMax < XML_NODESET_DEFAULT)
            locMax = XML_NODESET_DEFAULT;
        tmp = (xmlXPathObjectPtr *) xmlRealloc(locset->locTab,
                locMax * sizeof(xmlXPathObjectPtr));
        if (tmp == NULL) {
            xmlXPathPErrMemory(ctxt, "shrinking locset\n");
        } else {
            locset->locTab = tmp;
            locset->locMax = locMax;
        }
    }
 
    xpctxt->node = oldnode;
    xpctxt->doc = olddoc;
    xpctxt->contextSize = oldcs;
    xpctxt->proximityPosition = oldpp;
}
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
static void
xmlXPathCompOpEvalPredicate(xmlXPathParserContextPtr ctxt,
                xmlXPathStepOpPtr op,
                xmlNodeSetPtr set,
                            int minPos, int maxPos,
                int hasNsNodes)
{
    if (op->ch1 != -1) {
    xmlXPathCompExprPtr comp = ctxt->comp;
    /*
    * Process inner predicates first.
    */
    if (comp->steps[op->ch1].op != XPATH_OP_PREDICATE) {
            xmlGenericError(xmlGenericErrorContext,
                "xmlXPathCompOpEvalPredicate: Expected a predicate\n");
            XP_ERROR(XPATH_INVALID_OPERAND);
    }
        if (ctxt->context->depth >= XPATH_MAX_RECURSION_DEPTH)
            XP_ERROR(XPATH_RECURSION_LIMIT_EXCEEDED);
        ctxt->context->depth += 1;
    xmlXPathCompOpEvalPredicate(ctxt, &comp->steps[op->ch1], set,
                                    1, set->nodeNr, hasNsNodes);
        ctxt->context->depth -= 1;
    CHECK_ERROR;
    }
 
    if (op->ch2 != -1)
        xmlXPathNodeSetFilter(ctxt, set, op->ch2, minPos, maxPos, hasNsNodes);
}
 
static int
xmlXPathIsPositionalPredicate(xmlXPathParserContextPtr ctxt,
                xmlXPathStepOpPtr op,
                int *maxPos)
{
 
    xmlXPathStepOpPtr exprOp;
 
    /*
    * BIG NOTE: This is not intended for XPATH_OP_FILTER yet!
    */
 
    /*
    * If not -1, then ch1 will point to:
    * 1) For predicates (XPATH_OP_PREDICATE):
    *    - an inner predicate operator
    * 2) For filters (XPATH_OP_FILTER):
    *    - an inner filter operator OR
    *    - an expression selecting the node set.
    *      E.g. "key('a', 'b')" or "(//foo | //bar)".
    */
    if ((op->op != XPATH_OP_PREDICATE) && (op->op != XPATH_OP_FILTER))
    return(0);
 
    if (op->ch2 != -1) {
    exprOp = &ctxt->comp->steps[op->ch2];
    } else
    return(0);
 
    if ((exprOp != NULL) &&
    (exprOp->op == XPATH_OP_VALUE) &&
    (exprOp->value4 != NULL) &&
    (((xmlXPathObjectPtr) exprOp->value4)->type == XPATH_NUMBER))
    {
        double floatval = ((xmlXPathObjectPtr) exprOp->value4)->floatval;
 
    /*
    * We have a "[n]" predicate here.
    * TODO: Unfortunately this simplistic test here is not
    * able to detect a position() predicate in compound
    * expressions like "[@attr = 'a" and position() = 1],
    * and even not the usage of position() in
    * "[position() = 1]"; thus - obviously - a position-range,
    * like it "[position() < 5]", is also not detected.
    * Maybe we could rewrite the AST to ease the optimization.
    */
 
        if ((floatval > INT_MIN) && (floatval < INT_MAX)) {
        *maxPos = (int) floatval;
            if (floatval == (double) *maxPos)
                return(1);
        }
    }
    return(0);
}
 
static int
xmlXPathNodeCollectAndTest(xmlXPathParserContextPtr ctxt,
                           xmlXPathStepOpPtr op,
               xmlNodePtr * first, xmlNodePtr * last,
               int toBool)
{
 
#define XP_TEST_HIT \
    if (hasAxisRange != 0) { \
    if (++pos == maxPos) { \
        if (addNode(seq, cur) < 0) \
            ctxt->error = XPATH_MEMORY_ERROR; \
        goto axis_range_end; } \
    } else { \
    if (addNode(seq, cur) < 0) \
        ctxt->error = XPATH_MEMORY_ERROR; \
    if (breakOnFirstHit) goto first_hit; }
 
#define XP_TEST_HIT_NS \
    if (hasAxisRange != 0) { \
    if (++pos == maxPos) { \
        hasNsNodes = 1; \
        if (xmlXPathNodeSetAddNs(seq, xpctxt->node, (xmlNsPtr) cur) < 0) \
            ctxt->error = XPATH_MEMORY_ERROR; \
    goto axis_range_end; } \
    } else { \
    hasNsNodes = 1; \
    if (xmlXPathNodeSetAddNs(seq, xpctxt->node, (xmlNsPtr) cur) < 0) \
        ctxt->error = XPATH_MEMORY_ERROR; \
    if (breakOnFirstHit) goto first_hit; }
 
    xmlXPathAxisVal axis = (xmlXPathAxisVal) op->value;
    xmlXPathTestVal test = (xmlXPathTestVal) op->value2;
    xmlXPathTypeVal type = (xmlXPathTypeVal) op->value3;
    const xmlChar *prefix = op->value4;
    const xmlChar *name = op->value5;
    const xmlChar *URI = NULL;
 
    int total = 0, hasNsNodes = 0;
    /* The popped object holding the context nodes */
    xmlXPathObjectPtr obj;
    /* The set of context nodes for the node tests */
    xmlNodeSetPtr contextSeq;
    int contextIdx;
    xmlNodePtr contextNode;
    /* The final resulting node set wrt to all context nodes */
    xmlNodeSetPtr outSeq;
    /*
    * The temporary resulting node set wrt 1 context node.
    * Used to feed predicate evaluation.
    */
    xmlNodeSetPtr seq;
    xmlNodePtr cur;
    /* First predicate operator */
    xmlXPathStepOpPtr predOp;
    int maxPos; /* The requested position() (when a "[n]" predicate) */
    int hasPredicateRange, hasAxisRange, pos;
    int breakOnFirstHit;
 
    xmlXPathTraversalFunction next = NULL;
    int (*addNode) (xmlNodeSetPtr, xmlNodePtr);
    xmlXPathNodeSetMergeFunction mergeAndClear;
    xmlNodePtr oldContextNode;
    xmlXPathContextPtr xpctxt = ctxt->context;
 
 
    CHECK_TYPE0(XPATH_NODESET);
    obj = valuePop(ctxt);
    /*
    * Setup namespaces.
    */
    if (prefix != NULL) {
        URI = xmlXPathNsLookup(xpctxt, prefix);
        if (URI == NULL) {
        xmlXPathReleaseObject(xpctxt, obj);
            XP_ERROR0(XPATH_UNDEF_PREFIX_ERROR);
    }
    }
    /*
    * Setup axis.
    *
    * MAYBE FUTURE TODO: merging optimizations:
    * - If the nodes to be traversed wrt to the initial nodes and
    *   the current axis cannot overlap, then we could avoid searching
    *   for duplicates during the merge.
    *   But the question is how/when to evaluate if they cannot overlap.
    *   Example: if we know that for two initial nodes, the one is
    *   not in the ancestor-or-self axis of the other, then we could safely
    *   avoid a duplicate-aware merge, if the axis to be traversed is e.g.
    *   the descendant-or-self axis.
    */
    mergeAndClear = xmlXPathNodeSetMergeAndClear;
    switch (axis) {
        case AXIS_ANCESTOR:
            first = NULL;
            next = xmlXPathNextAncestor;
            break;
        case AXIS_ANCESTOR_OR_SELF:
            first = NULL;
            next = xmlXPathNextAncestorOrSelf;
            break;
        case AXIS_ATTRIBUTE:
            first = NULL;
        last = NULL;
            next = xmlXPathNextAttribute;
        mergeAndClear = xmlXPathNodeSetMergeAndClearNoDupls;
            break;
        case AXIS_CHILD:
        last = NULL;
        if (((test == NODE_TEST_NAME) || (test == NODE_TEST_ALL)) &&
        (type == NODE_TYPE_NODE))
        {
        /*
        * Optimization if an element node type is 'element'.
        */
        next = xmlXPathNextChildElement;
        } else
        next = xmlXPathNextChild;
        mergeAndClear = xmlXPathNodeSetMergeAndClearNoDupls;
            break;
        case AXIS_DESCENDANT:
        last = NULL;
            next = xmlXPathNextDescendant;
            break;
        case AXIS_DESCENDANT_OR_SELF:
        last = NULL;
            next = xmlXPathNextDescendantOrSelf;
            break;
        case AXIS_FOLLOWING:
        last = NULL;
            next = xmlXPathNextFollowing;
            break;
        case AXIS_FOLLOWING_SIBLING:
        last = NULL;
            next = xmlXPathNextFollowingSibling;
            break;
        case AXIS_NAMESPACE:
            first = NULL;
        last = NULL;
            next = (xmlXPathTraversalFunction) xmlXPathNextNamespace;
        mergeAndClear = xmlXPathNodeSetMergeAndClearNoDupls;
            break;
        case AXIS_PARENT:
            first = NULL;
            next = xmlXPathNextParent;
            break;
        case AXIS_PRECEDING:
            first = NULL;
            next = xmlXPathNextPrecedingInternal;
            break;
        case AXIS_PRECEDING_SIBLING:
            first = NULL;
            next = xmlXPathNextPrecedingSibling;
            break;
        case AXIS_SELF:
            first = NULL;
        last = NULL;
            next = xmlXPathNextSelf;
        mergeAndClear = xmlXPathNodeSetMergeAndClearNoDupls;
            break;
    }
 
    if (next == NULL) {
    xmlXPathReleaseObject(xpctxt, obj);
        return(0);
    }
    contextSeq = obj->nodesetval;
    if ((contextSeq == NULL) || (contextSeq->nodeNr <= 0)) {
    xmlXPathReleaseObject(xpctxt, obj);
        valuePush(ctxt, xmlXPathCacheWrapNodeSet(xpctxt, NULL));
        return(0);
    }
    /*
    * Predicate optimization ---------------------------------------------
    * If this step has a last predicate, which contains a position(),
    * then we'll optimize (although not exactly "position()", but only
    * the  short-hand form, i.e., "[n]".
    *
    * Example - expression "/foo[parent::bar][1]":
    *
    * COLLECT 'child' 'name' 'node' foo    -- op (we are here)
    *   ROOT                               -- op->ch1
    *   PREDICATE                          -- op->ch2 (predOp)
    *     PREDICATE                          -- predOp->ch1 = [parent::bar]
    *       SORT
    *         COLLECT  'parent' 'name' 'node' bar
    *           NODE
    *     ELEM Object is a number : 1        -- predOp->ch2 = [1]
    *
    */
    maxPos = 0;
    predOp = NULL;
    hasPredicateRange = 0;
    hasAxisRange = 0;
    if (op->ch2 != -1) {
    /*
    * There's at least one predicate. 16 == XPATH_OP_PREDICATE
    */
    predOp = &ctxt->comp->steps[op->ch2];
    if (xmlXPathIsPositionalPredicate(ctxt, predOp, &maxPos)) {
        if (predOp->ch1 != -1) {
        /*
        * Use the next inner predicate operator.
        */
        predOp = &ctxt->comp->steps[predOp->ch1];
        hasPredicateRange = 1;
        } else {
        /*
        * There's no other predicate than the [n] predicate.
        */
        predOp = NULL;
        hasAxisRange = 1;
        }
    }
    }
    breakOnFirstHit = ((toBool) && (predOp == NULL)) ? 1 : 0;
    /*
    * Axis traversal -----------------------------------------------------
    */
    /*
     * 2.3 Node Tests
     *  - For the attribute axis, the principal node type is attribute.
     *  - For the namespace axis, the principal node type is namespace.
     *  - For other axes, the principal node type is element.
     *
     * A node test * is true for any node of the
     * principal node type. For example, child::* will
     * select all element children of the context node
     */
    oldContextNode = xpctxt->node;
    addNode = xmlXPathNodeSetAddUnique;
    outSeq = NULL;
    seq = NULL;
    contextNode = NULL;
    contextIdx = 0;
 
 
    while (((contextIdx < contextSeq->nodeNr) || (contextNode != NULL)) &&
           (ctxt->error == XPATH_EXPRESSION_OK)) {
    xpctxt->node = contextSeq->nodeTab[contextIdx++];
 
    if (seq == NULL) {
        seq = xmlXPathNodeSetCreate(NULL);
        if (seq == NULL) {
                /* TODO: Propagate memory error. */
        total = 0;
        goto error;
        }
    }
    /*
    * Traverse the axis and test the nodes.
    */
    pos = 0;
    cur = NULL;
    hasNsNodes = 0;
        do {
            if (OP_LIMIT_EXCEEDED(ctxt, 1))
                goto error;
 
            cur = next(ctxt, cur);
            if (cur == NULL)
                break;
 
        /*
        * QUESTION TODO: What does the "first" and "last" stuff do?
        */
            if ((first != NULL) && (*first != NULL)) {
        if (*first == cur)
            break;
        if (((total % 256) == 0) &&
#ifdef XP_OPTIMIZED_NON_ELEM_COMPARISON
            (xmlXPathCmpNodesExt(*first, cur) >= 0))
#else
            (xmlXPathCmpNodes(*first, cur) >= 0))
#endif
        {
            break;
        }
        }
        if ((last != NULL) && (*last != NULL)) {
        if (*last == cur)
            break;
        if (((total % 256) == 0) &&
#ifdef XP_OPTIMIZED_NON_ELEM_COMPARISON
            (xmlXPathCmpNodesExt(cur, *last) >= 0))
#else
            (xmlXPathCmpNodes(cur, *last) >= 0))
#endif
        {
            break;
        }
        }
 
            total++;
 
        switch (test) {
                case NODE_TEST_NONE:
            total = 0;
                    STRANGE
            goto error;
                case NODE_TEST_TYPE:
            if (type == NODE_TYPE_NODE) {
            switch (cur->type) {
                case XML_DOCUMENT_NODE:
                case XML_HTML_DOCUMENT_NODE:
                case XML_ELEMENT_NODE:
                case XML_ATTRIBUTE_NODE:
                case XML_PI_NODE:
                case XML_COMMENT_NODE:
                case XML_CDATA_SECTION_NODE:
                case XML_TEXT_NODE:
                XP_TEST_HIT
                break;
                case XML_NAMESPACE_DECL: {
                if (axis == AXIS_NAMESPACE) {
                    XP_TEST_HIT_NS
                } else {
                                hasNsNodes = 1;
                    XP_TEST_HIT
                }
                break;
                            }
                default:
                break;
            }
            } else if (cur->type == (xmlElementType) type) {
            if (cur->type == XML_NAMESPACE_DECL)
                XP_TEST_HIT_NS
            else
                XP_TEST_HIT
            } else if ((type == NODE_TYPE_TEXT) &&
             (cur->type == XML_CDATA_SECTION_NODE))
            {
            XP_TEST_HIT
            }
            break;
                case NODE_TEST_PI:
                    if ((cur->type == XML_PI_NODE) &&
                        ((name == NULL) || xmlStrEqual(name, cur->name)))
            {
            XP_TEST_HIT
                    }
                    break;
                case NODE_TEST_ALL:
                    if (axis == AXIS_ATTRIBUTE) {
                        if (cur->type == XML_ATTRIBUTE_NODE)
            {
                            if (prefix == NULL)
                {
                XP_TEST_HIT
                            } else if ((cur->ns != NULL) &&
                (xmlStrEqual(URI, cur->ns->href)))
                {
                XP_TEST_HIT
                            }
                        }
                    } else if (axis == AXIS_NAMESPACE) {
                        if (cur->type == XML_NAMESPACE_DECL)
            {
                XP_TEST_HIT_NS
                        }
                    } else {
                        if (cur->type == XML_ELEMENT_NODE) {
                            if (prefix == NULL)
                {
                XP_TEST_HIT
 
                            } else if ((cur->ns != NULL) &&
                (xmlStrEqual(URI, cur->ns->href)))
                {
                XP_TEST_HIT
                            }
                        }
                    }
                    break;
                case NODE_TEST_NS:{
                        TODO;
                        break;
                    }
                case NODE_TEST_NAME:
                    if (axis == AXIS_ATTRIBUTE) {
                        if (cur->type != XML_ATTRIBUTE_NODE)
                break;
            } else if (axis == AXIS_NAMESPACE) {
                        if (cur->type != XML_NAMESPACE_DECL)
                break;
            } else {
                if (cur->type != XML_ELEMENT_NODE)
                break;
            }
                    switch (cur->type) {
                        case XML_ELEMENT_NODE:
                            if (xmlStrEqual(name, cur->name)) {
                                if (prefix == NULL) {
                                    if (cur->ns == NULL)
                    {
                    XP_TEST_HIT
                                    }
                                } else {
                                    if ((cur->ns != NULL) &&
                                        (xmlStrEqual(URI, cur->ns->href)))
                    {
                    XP_TEST_HIT
                                    }
                                }
                            }
                            break;
                        case XML_ATTRIBUTE_NODE:{
                                xmlAttrPtr attr = (xmlAttrPtr) cur;
 
                                if (xmlStrEqual(name, attr->name)) {
                                    if (prefix == NULL) {
                                        if ((attr->ns == NULL) ||
                                            (attr->ns->prefix == NULL))
                    {
                        XP_TEST_HIT
                                        }
                                    } else {
                                        if ((attr->ns != NULL) &&
                                            (xmlStrEqual(URI,
                          attr->ns->href)))
                    {
                        XP_TEST_HIT
                                        }
                                    }
                                }
                                break;
                            }
                        case XML_NAMESPACE_DECL:
                            if (cur->type == XML_NAMESPACE_DECL) {
                                xmlNsPtr ns = (xmlNsPtr) cur;
 
                                if ((ns->prefix != NULL) && (name != NULL)
                                    && (xmlStrEqual(ns->prefix, name)))
                {
                    XP_TEST_HIT_NS
                                }
                            }
                            break;
                        default:
                            break;
                    }
                    break;
        } /* switch(test) */
        } while ((cur != NULL) && (ctxt->error == XPATH_EXPRESSION_OK));
 
    goto apply_predicates;
 
axis_range_end: /* ----------------------------------------------------- */
    /*
    * We have a "/foo[n]", and position() = n was reached.
    * Note that we can have as well "/foo/::parent::foo[1]", so
    * a duplicate-aware merge is still needed.
    * Merge with the result.
    */
    if (outSeq == NULL) {
        outSeq = seq;
        seq = NULL;
    } else
            /* TODO: Check memory error. */
        outSeq = mergeAndClear(outSeq, seq);
    /*
    * Break if only a true/false result was requested.
    */
    if (toBool)
        break;
    continue;
 
first_hit: /* ---------------------------------------------------------- */
    /*
    * Break if only a true/false result was requested and
    * no predicates existed and a node test succeeded.
    */
    if (outSeq == NULL) {
        outSeq = seq;
        seq = NULL;
    } else
            /* TODO: Check memory error. */
        outSeq = mergeAndClear(outSeq, seq);
    break;
 
apply_predicates: /* --------------------------------------------------- */
        if (ctxt->error != XPATH_EXPRESSION_OK)
        goto error;
 
        /*
    * Apply predicates.
    */
        if ((predOp != NULL) && (seq->nodeNr > 0)) {
        /*
        * E.g. when we have a "/foo[some expression][n]".
        */
        /*
        * QUESTION TODO: The old predicate evaluation took into
        *  account location-sets.
        *  (E.g. ctxt->value->type == XPATH_LOCATIONSET)
        *  Do we expect such a set here?
        *  All what I learned now from the evaluation semantics
        *  does not indicate that a location-set will be processed
        *  here, so this looks OK.
        */
        /*
        * Iterate over all predicates, starting with the outermost
        * predicate.
        * TODO: Problem: we cannot execute the inner predicates first
        *  since we cannot go back *up* the operator tree!
        *  Options we have:
        *  1) Use of recursive functions (like is it currently done
        *     via xmlXPathCompOpEval())
        *  2) Add a predicate evaluation information stack to the
        *     context struct
        *  3) Change the way the operators are linked; we need a
        *     "parent" field on xmlXPathStepOp
        *
        * For the moment, I'll try to solve this with a recursive
        * function: xmlXPathCompOpEvalPredicate().
        */
        if (hasPredicateRange != 0)
        xmlXPathCompOpEvalPredicate(ctxt, predOp, seq, maxPos, maxPos,
                        hasNsNodes);
        else
        xmlXPathCompOpEvalPredicate(ctxt, predOp, seq, 1, seq->nodeNr,
                        hasNsNodes);
 
        if (ctxt->error != XPATH_EXPRESSION_OK) {
        total = 0;
        goto error;
        }
        }
 
        if (seq->nodeNr > 0) {
        /*
        * Add to result set.
        */
        if (outSeq == NULL) {
        outSeq = seq;
        seq = NULL;
        } else {
                /* TODO: Check memory error. */
        outSeq = mergeAndClear(outSeq, seq);
        }
 
            if (toBool)
                break;
    }
    }
 
error:
    if ((obj->boolval) && (obj->user != NULL)) {
    /*
    * QUESTION TODO: What does this do and why?
    * TODO: Do we have to do this also for the "error"
    * cleanup further down?
    */
    ctxt->value->boolval = 1;
    ctxt->value->user = obj->user;
    obj->user = NULL;
    obj->boolval = 0;
    }
    xmlXPathReleaseObject(xpctxt, obj);
 
    /*
    * Ensure we return at least an empty set.
    */
    if (outSeq == NULL) {
    if ((seq != NULL) && (seq->nodeNr == 0))
        outSeq = seq;
    else
            /* TODO: Check memory error. */
        outSeq = xmlXPathNodeSetCreate(NULL);
    }
    if ((seq != NULL) && (seq != outSeq)) {
     xmlXPathFreeNodeSet(seq);
    }
    /*
    * Hand over the result. Better to push the set also in
    * case of errors.
    */
    valuePush(ctxt, xmlXPathCacheWrapNodeSet(xpctxt, outSeq));
    /*
    * Reset the context node.
    */
    xpctxt->node = oldContextNode;
    /*
    * When traversing the namespace axis in "toBool" mode, it's
    * possible that tmpNsList wasn't freed.
    */
    if (xpctxt->tmpNsList != NULL) {
        xmlFree(xpctxt->tmpNsList);
        xpctxt->tmpNsList = NULL;
    }
 
    return(total);
}
 
static int
xmlXPathCompOpEvalFilterFirst(xmlXPathParserContextPtr ctxt,
                  xmlXPathStepOpPtr op, xmlNodePtr * first);
 
static int
xmlXPathCompOpEvalFirst(xmlXPathParserContextPtr ctxt,
                        xmlXPathStepOpPtr op, xmlNodePtr * first)
{
    int total = 0, cur;
    xmlXPathCompExprPtr comp;
    xmlXPathObjectPtr arg1, arg2;
 
    CHECK_ERROR0;
    if (OP_LIMIT_EXCEEDED(ctxt, 1))
        return(0);
    if (ctxt->context->depth >= XPATH_MAX_RECURSION_DEPTH)
        XP_ERROR0(XPATH_RECURSION_LIMIT_EXCEEDED);
    ctxt->context->depth += 1;
    comp = ctxt->comp;
    switch (op->op) {
        case XPATH_OP_END:
            break;
        case XPATH_OP_UNION:
            total =
                xmlXPathCompOpEvalFirst(ctxt, &comp->steps[op->ch1],
                                        first);
        CHECK_ERROR0;
            if ((ctxt->value != NULL)
                && (ctxt->value->type == XPATH_NODESET)
                && (ctxt->value->nodesetval != NULL)
                && (ctxt->value->nodesetval->nodeNr >= 1)) {
                /*
                 * limit tree traversing to first node in the result
                 */
        /*
        * OPTIMIZE TODO: This implicitly sorts
        *  the result, even if not needed. E.g. if the argument
        *  of the count() function, no sorting is needed.
        * OPTIMIZE TODO: How do we know if the node-list wasn't
        *  already sorted?
        */
        if (ctxt->value->nodesetval->nodeNr > 1)
            xmlXPathNodeSetSort(ctxt->value->nodesetval);
                *first = ctxt->value->nodesetval->nodeTab[0];
            }
            cur =
                xmlXPathCompOpEvalFirst(ctxt, &comp->steps[op->ch2],
                                        first);
        CHECK_ERROR0;
 
            arg2 = valuePop(ctxt);
            arg1 = valuePop(ctxt);
            if ((arg1 == NULL) || (arg1->type != XPATH_NODESET) ||
                (arg2 == NULL) || (arg2->type != XPATH_NODESET)) {
            xmlXPathReleaseObject(ctxt->context, arg1);
            xmlXPathReleaseObject(ctxt->context, arg2);
                XP_ERROR0(XPATH_INVALID_TYPE);
            }
            if ((ctxt->context->opLimit != 0) &&
                (((arg1->nodesetval != NULL) &&
                  (xmlXPathCheckOpLimit(ctxt,
                                        arg1->nodesetval->nodeNr) < 0)) ||
                 ((arg2->nodesetval != NULL) &&
                  (xmlXPathCheckOpLimit(ctxt,
                                        arg2->nodesetval->nodeNr) < 0)))) {
            xmlXPathReleaseObject(ctxt->context, arg1);
            xmlXPathReleaseObject(ctxt->context, arg2);
                break;
            }
 
            /* TODO: Check memory error. */
            arg1->nodesetval = xmlXPathNodeSetMerge(arg1->nodesetval,
                                                    arg2->nodesetval);
            valuePush(ctxt, arg1);
        xmlXPathReleaseObject(ctxt->context, arg2);
            /* optimizer */
        if (total > cur)
        xmlXPathCompSwap(op);
            total += cur;
            break;
        case XPATH_OP_ROOT:
            xmlXPathRoot(ctxt);
            break;
        case XPATH_OP_NODE:
            if (op->ch1 != -1)
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            if (op->ch2 != -1)
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        CHECK_ERROR0;
        valuePush(ctxt, xmlXPathCacheNewNodeSet(ctxt->context,
        ctxt->context->node));
            break;
        case XPATH_OP_COLLECT:{
                if (op->ch1 == -1)
                    break;
 
                total = xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
 
                total += xmlXPathNodeCollectAndTest(ctxt, op, first, NULL, 0);
                break;
            }
        case XPATH_OP_VALUE:
            valuePush(ctxt,
                      xmlXPathCacheObjectCopy(ctxt->context,
            (xmlXPathObjectPtr) op->value4));
            break;
        case XPATH_OP_SORT:
            if (op->ch1 != -1)
                total +=
                    xmlXPathCompOpEvalFirst(ctxt, &comp->steps[op->ch1],
                                            first);
        CHECK_ERROR0;
            if ((ctxt->value != NULL)
                && (ctxt->value->type == XPATH_NODESET)
                && (ctxt->value->nodesetval != NULL)
        && (ctxt->value->nodesetval->nodeNr > 1))
                xmlXPathNodeSetSort(ctxt->value->nodesetval);
            break;
#ifdef XP_OPTIMIZED_FILTER_FIRST
    case XPATH_OP_FILTER:
                total += xmlXPathCompOpEvalFilterFirst(ctxt, op, first);
            break;
#endif
        default:
            total += xmlXPathCompOpEval(ctxt, op);
            break;
    }
 
    ctxt->context->depth -= 1;
    return(total);
}
 
static int
xmlXPathCompOpEvalLast(xmlXPathParserContextPtr ctxt, xmlXPathStepOpPtr op,
                       xmlNodePtr * last)
{
    int total = 0, cur;
    xmlXPathCompExprPtr comp;
    xmlXPathObjectPtr arg1, arg2;
 
    CHECK_ERROR0;
    if (OP_LIMIT_EXCEEDED(ctxt, 1))
        return(0);
    if (ctxt->context->depth >= XPATH_MAX_RECURSION_DEPTH)
        XP_ERROR0(XPATH_RECURSION_LIMIT_EXCEEDED);
    ctxt->context->depth += 1;
    comp = ctxt->comp;
    switch (op->op) {
        case XPATH_OP_END:
            break;
        case XPATH_OP_UNION:
            total =
                xmlXPathCompOpEvalLast(ctxt, &comp->steps[op->ch1], last);
        CHECK_ERROR0;
            if ((ctxt->value != NULL)
                && (ctxt->value->type == XPATH_NODESET)
                && (ctxt->value->nodesetval != NULL)
                && (ctxt->value->nodesetval->nodeNr >= 1)) {
                /*
                 * limit tree traversing to first node in the result
                 */
        if (ctxt->value->nodesetval->nodeNr > 1)
            xmlXPathNodeSetSort(ctxt->value->nodesetval);
                *last =
                    ctxt->value->nodesetval->nodeTab[ctxt->value->
                                                     nodesetval->nodeNr -
                                                     1];
            }
            cur =
                xmlXPathCompOpEvalLast(ctxt, &comp->steps[op->ch2], last);
        CHECK_ERROR0;
            if ((ctxt->value != NULL)
                && (ctxt->value->type == XPATH_NODESET)
                && (ctxt->value->nodesetval != NULL)
                && (ctxt->value->nodesetval->nodeNr >= 1)) { /* TODO: NOP ? */
            }
 
            arg2 = valuePop(ctxt);
            arg1 = valuePop(ctxt);
            if ((arg1 == NULL) || (arg1->type != XPATH_NODESET) ||
                (arg2 == NULL) || (arg2->type != XPATH_NODESET)) {
            xmlXPathReleaseObject(ctxt->context, arg1);
            xmlXPathReleaseObject(ctxt->context, arg2);
                XP_ERROR0(XPATH_INVALID_TYPE);
            }
            if ((ctxt->context->opLimit != 0) &&
                (((arg1->nodesetval != NULL) &&
                  (xmlXPathCheckOpLimit(ctxt,
                                        arg1->nodesetval->nodeNr) < 0)) ||
                 ((arg2->nodesetval != NULL) &&
                  (xmlXPathCheckOpLimit(ctxt,
                                        arg2->nodesetval->nodeNr) < 0)))) {
            xmlXPathReleaseObject(ctxt->context, arg1);
            xmlXPathReleaseObject(ctxt->context, arg2);
                break;
            }
 
            /* TODO: Check memory error. */
            arg1->nodesetval = xmlXPathNodeSetMerge(arg1->nodesetval,
                                                    arg2->nodesetval);
            valuePush(ctxt, arg1);
        xmlXPathReleaseObject(ctxt->context, arg2);
            /* optimizer */
        if (total > cur)
        xmlXPathCompSwap(op);
            total += cur;
            break;
        case XPATH_OP_ROOT:
            xmlXPathRoot(ctxt);
            break;
        case XPATH_OP_NODE:
            if (op->ch1 != -1)
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            if (op->ch2 != -1)
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        CHECK_ERROR0;
        valuePush(ctxt, xmlXPathCacheNewNodeSet(ctxt->context,
        ctxt->context->node));
            break;
        case XPATH_OP_COLLECT:{
                if (op->ch1 == -1)
                    break;
 
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
 
                total += xmlXPathNodeCollectAndTest(ctxt, op, NULL, last, 0);
                break;
            }
        case XPATH_OP_VALUE:
            valuePush(ctxt,
                      xmlXPathCacheObjectCopy(ctxt->context,
            (xmlXPathObjectPtr) op->value4));
            break;
        case XPATH_OP_SORT:
            if (op->ch1 != -1)
                total +=
                    xmlXPathCompOpEvalLast(ctxt, &comp->steps[op->ch1],
                                           last);
        CHECK_ERROR0;
            if ((ctxt->value != NULL)
                && (ctxt->value->type == XPATH_NODESET)
                && (ctxt->value->nodesetval != NULL)
        && (ctxt->value->nodesetval->nodeNr > 1))
                xmlXPathNodeSetSort(ctxt->value->nodesetval);
            break;
        default:
            total += xmlXPathCompOpEval(ctxt, op);
            break;
    }
 
    ctxt->context->depth -= 1;
    return (total);
}
 
#ifdef XP_OPTIMIZED_FILTER_FIRST
static int
xmlXPathCompOpEvalFilterFirst(xmlXPathParserContextPtr ctxt,
                  xmlXPathStepOpPtr op, xmlNodePtr * first)
{
    int total = 0;
    xmlXPathCompExprPtr comp;
    xmlXPathObjectPtr obj;
    xmlNodeSetPtr set;
 
    CHECK_ERROR0;
    comp = ctxt->comp;
    /*
    * Optimization for ()[last()] selection i.e. the last elem
    */
    if ((op->ch1 != -1) && (op->ch2 != -1) &&
    (comp->steps[op->ch1].op == XPATH_OP_SORT) &&
    (comp->steps[op->ch2].op == XPATH_OP_SORT)) {
    int f = comp->steps[op->ch2].ch1;
 
    if ((f != -1) &&
        (comp->steps[f].op == XPATH_OP_FUNCTION) &&
        (comp->steps[f].value5 == NULL) &&
        (comp->steps[f].value == 0) &&
        (comp->steps[f].value4 != NULL) &&
        (xmlStrEqual
        (comp->steps[f].value4, BAD_CAST "last"))) {
        xmlNodePtr last = NULL;
 
        total +=
        xmlXPathCompOpEvalLast(ctxt,
            &comp->steps[op->ch1],
            &last);
        CHECK_ERROR0;
        /*
        * The nodeset should be in document order,
        * Keep only the last value
        */
        if ((ctxt->value != NULL) &&
        (ctxt->value->type == XPATH_NODESET) &&
        (ctxt->value->nodesetval != NULL) &&
        (ctxt->value->nodesetval->nodeTab != NULL) &&
        (ctxt->value->nodesetval->nodeNr > 1)) {
                xmlXPathNodeSetKeepLast(ctxt->value->nodesetval);
        *first = *(ctxt->value->nodesetval->nodeTab);
        }
        return (total);
    }
    }
 
    if (op->ch1 != -1)
    total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
    CHECK_ERROR0;
    if (op->ch2 == -1)
    return (total);
    if (ctxt->value == NULL)
    return (total);
 
#ifdef LIBXML_XPTR_LOCS_ENABLED
    /*
    * Hum are we filtering the result of an XPointer expression
    */
    if (ctxt->value->type == XPATH_LOCATIONSET) {
        xmlLocationSetPtr locset = ctxt->value->user;
 
        if (locset != NULL) {
            xmlXPathLocationSetFilter(ctxt, locset, op->ch2, 1, 1);
            if (locset->locNr > 0)
                *first = (xmlNodePtr) locset->locTab[0]->user;
        }
 
    return (total);
    }
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
    /*
     * In case of errors, xmlXPathNodeSetFilter can pop additional nodes from
     * the stack. We have to temporarily remove the nodeset object from the
     * stack to avoid freeing it prematurely.
     */
    CHECK_TYPE0(XPATH_NODESET);
    obj = valuePop(ctxt);
    set = obj->nodesetval;
    if (set != NULL) {
        xmlXPathNodeSetFilter(ctxt, set, op->ch2, 1, 1, 1);
        if (set->nodeNr > 0)
            *first = set->nodeTab[0];
    }
    valuePush(ctxt, obj);
 
    return (total);
}
#endif /* XP_OPTIMIZED_FILTER_FIRST */
 
static int
xmlXPathCompOpEval(xmlXPathParserContextPtr ctxt, xmlXPathStepOpPtr op)
{
    int total = 0;
    int equal, ret;
    xmlXPathCompExprPtr comp;
    xmlXPathObjectPtr arg1, arg2;
 
    CHECK_ERROR0;
    if (OP_LIMIT_EXCEEDED(ctxt, 1))
        return(0);
    if (ctxt->context->depth >= XPATH_MAX_RECURSION_DEPTH)
        XP_ERROR0(XPATH_RECURSION_LIMIT_EXCEEDED);
    ctxt->context->depth += 1;
    comp = ctxt->comp;
    switch (op->op) {
        case XPATH_OP_END:
            break;
        case XPATH_OP_AND:
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            xmlXPathBooleanFunction(ctxt, 1);
            if ((ctxt->value == NULL) || (ctxt->value->boolval == 0))
                break;
            arg2 = valuePop(ctxt);
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        if (ctxt->error) {
        xmlXPathFreeObject(arg2);
        break;
        }
            xmlXPathBooleanFunction(ctxt, 1);
            if (ctxt->value != NULL)
                ctxt->value->boolval &= arg2->boolval;
        xmlXPathReleaseObject(ctxt->context, arg2);
            break;
        case XPATH_OP_OR:
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            xmlXPathBooleanFunction(ctxt, 1);
            if ((ctxt->value == NULL) || (ctxt->value->boolval == 1))
                break;
            arg2 = valuePop(ctxt);
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        if (ctxt->error) {
        xmlXPathFreeObject(arg2);
        break;
        }
            xmlXPathBooleanFunction(ctxt, 1);
            if (ctxt->value != NULL)
                ctxt->value->boolval |= arg2->boolval;
        xmlXPathReleaseObject(ctxt->context, arg2);
            break;
        case XPATH_OP_EQUAL:
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        CHECK_ERROR0;
        if (op->value)
        equal = xmlXPathEqualValues(ctxt);
        else
        equal = xmlXPathNotEqualValues(ctxt);
        valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, equal));
            break;
        case XPATH_OP_CMP:
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        CHECK_ERROR0;
            ret = xmlXPathCompareValues(ctxt, op->value, op->value2);
        valuePush(ctxt, xmlXPathCacheNewBoolean(ctxt->context, ret));
            break;
        case XPATH_OP_PLUS:
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            if (op->ch2 != -1) {
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        }
        CHECK_ERROR0;
            if (op->value == 0)
                xmlXPathSubValues(ctxt);
            else if (op->value == 1)
                xmlXPathAddValues(ctxt);
            else if (op->value == 2)
                xmlXPathValueFlipSign(ctxt);
            else if (op->value == 3) {
                CAST_TO_NUMBER;
                CHECK_TYPE0(XPATH_NUMBER);
            }
            break;
        case XPATH_OP_MULT:
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        CHECK_ERROR0;
            if (op->value == 0)
                xmlXPathMultValues(ctxt);
            else if (op->value == 1)
                xmlXPathDivValues(ctxt);
            else if (op->value == 2)
                xmlXPathModValues(ctxt);
            break;
        case XPATH_OP_UNION:
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        CHECK_ERROR0;
 
            arg2 = valuePop(ctxt);
            arg1 = valuePop(ctxt);
            if ((arg1 == NULL) || (arg1->type != XPATH_NODESET) ||
                (arg2 == NULL) || (arg2->type != XPATH_NODESET)) {
            xmlXPathReleaseObject(ctxt->context, arg1);
            xmlXPathReleaseObject(ctxt->context, arg2);
                XP_ERROR0(XPATH_INVALID_TYPE);
            }
            if ((ctxt->context->opLimit != 0) &&
                (((arg1->nodesetval != NULL) &&
                  (xmlXPathCheckOpLimit(ctxt,
                                        arg1->nodesetval->nodeNr) < 0)) ||
                 ((arg2->nodesetval != NULL) &&
                  (xmlXPathCheckOpLimit(ctxt,
                                        arg2->nodesetval->nodeNr) < 0)))) {
            xmlXPathReleaseObject(ctxt->context, arg1);
            xmlXPathReleaseObject(ctxt->context, arg2);
                break;
            }
 
        if ((arg1->nodesetval == NULL) ||
        ((arg2->nodesetval != NULL) &&
         (arg2->nodesetval->nodeNr != 0)))
        {
                /* TODO: Check memory error. */
        arg1->nodesetval = xmlXPathNodeSetMerge(arg1->nodesetval,
                            arg2->nodesetval);
        }
 
            valuePush(ctxt, arg1);
        xmlXPathReleaseObject(ctxt->context, arg2);
            break;
        case XPATH_OP_ROOT:
            xmlXPathRoot(ctxt);
            break;
        case XPATH_OP_NODE:
            if (op->ch1 != -1)
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            if (op->ch2 != -1)
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
        CHECK_ERROR0;
        valuePush(ctxt, xmlXPathCacheNewNodeSet(ctxt->context,
        ctxt->context->node));
            break;
        case XPATH_OP_COLLECT:{
                if (op->ch1 == -1)
                    break;
 
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
 
                total += xmlXPathNodeCollectAndTest(ctxt, op, NULL, NULL, 0);
                break;
            }
        case XPATH_OP_VALUE:
            valuePush(ctxt,
                      xmlXPathCacheObjectCopy(ctxt->context,
            (xmlXPathObjectPtr) op->value4));
            break;
        case XPATH_OP_VARIABLE:{
        xmlXPathObjectPtr val;
 
                if (op->ch1 != -1)
                    total +=
                        xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
                if (op->value5 == NULL) {
            val = xmlXPathVariableLookup(ctxt->context, op->value4);
            if (val == NULL)
            XP_ERROR0(XPATH_UNDEF_VARIABLE_ERROR);
                    valuePush(ctxt, val);
        } else {
                    const xmlChar *URI;
 
                    URI = xmlXPathNsLookup(ctxt->context, op->value5);
                    if (URI == NULL) {
                        xmlGenericError(xmlGenericErrorContext,
            "xmlXPathCompOpEval: variable %s bound to undefined prefix %s\n",
                                    (char *) op->value4, (char *)op->value5);
                        ctxt->error = XPATH_UNDEF_PREFIX_ERROR;
                        break;
                    }
            val = xmlXPathVariableLookupNS(ctxt->context,
                                                       op->value4, URI);
            if (val == NULL)
            XP_ERROR0(XPATH_UNDEF_VARIABLE_ERROR);
                    valuePush(ctxt, val);
                }
                break;
            }
        case XPATH_OP_FUNCTION:{
                xmlXPathFunction func;
                const xmlChar *oldFunc, *oldFuncURI;
        int i;
                int frame;
 
                frame = ctxt->valueNr;
                if (op->ch1 != -1) {
                    total +=
                        xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
                    if (ctxt->error != XPATH_EXPRESSION_OK)
                        break;
                }
        if (ctxt->valueNr < frame + op->value) {
            xmlGenericError(xmlGenericErrorContext,
                "xmlXPathCompOpEval: parameter error\n");
            ctxt->error = XPATH_INVALID_OPERAND;
            break;
        }
        for (i = 0; i < op->value; i++) {
            if (ctxt->valueTab[(ctxt->valueNr - 1) - i] == NULL) {
            xmlGenericError(xmlGenericErrorContext,
                "xmlXPathCompOpEval: parameter error\n");
            ctxt->error = XPATH_INVALID_OPERAND;
            break;
            }
                }
                if (op->cache != NULL)
                    func = op->cache;
                else {
                    const xmlChar *URI = NULL;
 
                    if (op->value5 == NULL)
                        func =
                            xmlXPathFunctionLookup(ctxt->context,
                                                   op->value4);
                    else {
                        URI = xmlXPathNsLookup(ctxt->context, op->value5);
                        if (URI == NULL) {
                            xmlGenericError(xmlGenericErrorContext,
            "xmlXPathCompOpEval: function %s bound to undefined prefix %s\n",
                                    (char *)op->value4, (char *)op->value5);
                            ctxt->error = XPATH_UNDEF_PREFIX_ERROR;
                            break;
                        }
                        func = xmlXPathFunctionLookupNS(ctxt->context,
                                                        op->value4, URI);
                    }
                    if (func == NULL) {
                        xmlGenericError(xmlGenericErrorContext,
                                "xmlXPathCompOpEval: function %s not found\n",
                                        (char *)op->value4);
                        XP_ERROR0(XPATH_UNKNOWN_FUNC_ERROR);
                    }
                    op->cache = func;
                    op->cacheURI = (void *) URI;
                }
                oldFunc = ctxt->context->function;
                oldFuncURI = ctxt->context->functionURI;
                ctxt->context->function = op->value4;
                ctxt->context->functionURI = op->cacheURI;
                func(ctxt, op->value);
                ctxt->context->function = oldFunc;
                ctxt->context->functionURI = oldFuncURI;
                if ((ctxt->error == XPATH_EXPRESSION_OK) &&
                    (ctxt->valueNr != frame + 1))
                    XP_ERROR0(XPATH_STACK_ERROR);
                break;
            }
        case XPATH_OP_ARG:
            if (op->ch1 != -1) {
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
            CHECK_ERROR0;
            }
            if (op->ch2 != -1) {
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch2]);
            CHECK_ERROR0;
        }
            break;
        case XPATH_OP_PREDICATE:
        case XPATH_OP_FILTER:{
                xmlXPathObjectPtr obj;
                xmlNodeSetPtr set;
 
                /*
                 * Optimization for ()[1] selection i.e. the first elem
                 */
                if ((op->ch1 != -1) && (op->ch2 != -1) &&
#ifdef XP_OPTIMIZED_FILTER_FIRST
            /*
            * FILTER TODO: Can we assume that the inner processing
            *  will result in an ordered list if we have an
            *  XPATH_OP_FILTER?
            *  What about an additional field or flag on
            *  xmlXPathObject like @sorted ? This way we wouldn't need
            *  to assume anything, so it would be more robust and
            *  easier to optimize.
            */
                    ((comp->steps[op->ch1].op == XPATH_OP_SORT) || /* 18 */
             (comp->steps[op->ch1].op == XPATH_OP_FILTER)) && /* 17 */
#else
            (comp->steps[op->ch1].op == XPATH_OP_SORT) &&
#endif
                    (comp->steps[op->ch2].op == XPATH_OP_VALUE)) { /* 12 */
                    xmlXPathObjectPtr val;
 
                    val = comp->steps[op->ch2].value4;
                    if ((val != NULL) && (val->type == XPATH_NUMBER) &&
                        (val->floatval == 1.0)) {
                        xmlNodePtr first = NULL;
 
                        total +=
                            xmlXPathCompOpEvalFirst(ctxt,
                                                    &comp->steps[op->ch1],
                                                    &first);
            CHECK_ERROR0;
                        /*
                         * The nodeset should be in document order,
                         * Keep only the first value
                         */
                        if ((ctxt->value != NULL) &&
                            (ctxt->value->type == XPATH_NODESET) &&
                            (ctxt->value->nodesetval != NULL) &&
                            (ctxt->value->nodesetval->nodeNr > 1))
                            xmlXPathNodeSetClearFromPos(ctxt->value->nodesetval,
                                                        1, 1);
                        break;
                    }
                }
                /*
                 * Optimization for ()[last()] selection i.e. the last elem
                 */
                if ((op->ch1 != -1) && (op->ch2 != -1) &&
                    (comp->steps[op->ch1].op == XPATH_OP_SORT) &&
                    (comp->steps[op->ch2].op == XPATH_OP_SORT)) {
                    int f = comp->steps[op->ch2].ch1;
 
                    if ((f != -1) &&
                        (comp->steps[f].op == XPATH_OP_FUNCTION) &&
                        (comp->steps[f].value5 == NULL) &&
                        (comp->steps[f].value == 0) &&
                        (comp->steps[f].value4 != NULL) &&
                        (xmlStrEqual
                         (comp->steps[f].value4, BAD_CAST "last"))) {
                        xmlNodePtr last = NULL;
 
                        total +=
                            xmlXPathCompOpEvalLast(ctxt,
                                                   &comp->steps[op->ch1],
                                                   &last);
            CHECK_ERROR0;
                        /*
                         * The nodeset should be in document order,
                         * Keep only the last value
                         */
                        if ((ctxt->value != NULL) &&
                            (ctxt->value->type == XPATH_NODESET) &&
                            (ctxt->value->nodesetval != NULL) &&
                            (ctxt->value->nodesetval->nodeTab != NULL) &&
                            (ctxt->value->nodesetval->nodeNr > 1))
                            xmlXPathNodeSetKeepLast(ctxt->value->nodesetval);
                        break;
                    }
                }
        /*
        * Process inner predicates first.
        * Example "index[parent::book][1]":
        * ...
        *   PREDICATE   <-- we are here "[1]"
        *     PREDICATE <-- process "[parent::book]" first
        *       SORT
        *         COLLECT  'parent' 'name' 'node' book
        *           NODE
        *     ELEM Object is a number : 1
        */
                if (op->ch1 != -1)
                    total +=
                        xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
                if (op->ch2 == -1)
                    break;
                if (ctxt->value == NULL)
                    break;
 
#ifdef LIBXML_XPTR_LOCS_ENABLED
                /*
                 * Hum are we filtering the result of an XPointer expression
                 */
                if (ctxt->value->type == XPATH_LOCATIONSET) {
                    xmlLocationSetPtr locset = ctxt->value->user;
                    xmlXPathLocationSetFilter(ctxt, locset, op->ch2,
                                              1, locset->locNr);
                    break;
                }
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
                /*
                 * In case of errors, xmlXPathNodeSetFilter can pop additional
                 * nodes from the stack. We have to temporarily remove the
                 * nodeset object from the stack to avoid freeing it
                 * prematurely.
                 */
                CHECK_TYPE0(XPATH_NODESET);
                obj = valuePop(ctxt);
                set = obj->nodesetval;
                if (set != NULL)
                    xmlXPathNodeSetFilter(ctxt, set, op->ch2,
                                          1, set->nodeNr, 1);
                valuePush(ctxt, obj);
                break;
            }
        case XPATH_OP_SORT:
            if (op->ch1 != -1)
                total += xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
        CHECK_ERROR0;
            if ((ctxt->value != NULL) &&
                (ctxt->value->type == XPATH_NODESET) &&
                (ctxt->value->nodesetval != NULL) &&
        (ctxt->value->nodesetval->nodeNr > 1))
        {
                xmlXPathNodeSetSort(ctxt->value->nodesetval);
        }
            break;
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_OP_RANGETO:{
                xmlXPathObjectPtr range;
                xmlXPathObjectPtr res, obj;
                xmlXPathObjectPtr tmp;
                xmlLocationSetPtr newlocset = NULL;
            xmlLocationSetPtr oldlocset;
                xmlNodeSetPtr oldset;
                xmlNodePtr oldnode = ctxt->context->node;
                int oldcs = ctxt->context->contextSize;
                int oldpp = ctxt->context->proximityPosition;
                int i, j;
 
                if (op->ch1 != -1) {
                    total +=
                        xmlXPathCompOpEval(ctxt, &comp->steps[op->ch1]);
                    CHECK_ERROR0;
                }
                if (ctxt->value == NULL) {
                    XP_ERROR0(XPATH_INVALID_OPERAND);
                }
                if (op->ch2 == -1)
                    break;
 
                if (ctxt->value->type == XPATH_LOCATIONSET) {
                    /*
                     * Extract the old locset, and then evaluate the result of the
                     * expression for all the element in the locset. use it to grow
                     * up a new locset.
                     */
                    CHECK_TYPE0(XPATH_LOCATIONSET);
 
                    if ((ctxt->value->user == NULL) ||
                        (((xmlLocationSetPtr) ctxt->value->user)->locNr == 0))
                        break;
 
                    obj = valuePop(ctxt);
                    oldlocset = obj->user;
 
                    newlocset = xmlXPtrLocationSetCreate(NULL);
 
                    for (i = 0; i < oldlocset->locNr; i++) {
                        /*
                         * Run the evaluation with a node list made of a
                         * single item in the nodelocset.
                         */
                        ctxt->context->node = oldlocset->locTab[i]->user;
                        ctxt->context->contextSize = oldlocset->locNr;
                        ctxt->context->proximityPosition = i + 1;
            tmp = xmlXPathCacheNewNodeSet(ctxt->context,
                ctxt->context->node);
                        valuePush(ctxt, tmp);
 
                        if (op->ch2 != -1)
                            total +=
                                xmlXPathCompOpEval(ctxt,
                                                   &comp->steps[op->ch2]);
            if (ctxt->error != XPATH_EXPRESSION_OK) {
                            xmlXPtrFreeLocationSet(newlocset);
                            goto rangeto_error;
            }
 
                        res = valuePop(ctxt);
            if (res->type == XPATH_LOCATIONSET) {
                xmlLocationSetPtr rloc =
                    (xmlLocationSetPtr)res->user;
                for (j=0; j<rloc->locNr; j++) {
                    range = xmlXPtrNewRange(
                  oldlocset->locTab[i]->user,
                  oldlocset->locTab[i]->index,
                  rloc->locTab[j]->user2,
                  rloc->locTab[j]->index2);
                if (range != NULL) {
                    xmlXPtrLocationSetAdd(newlocset, range);
                }
                }
            } else {
                range = xmlXPtrNewRangeNodeObject(
                (xmlNodePtr)oldlocset->locTab[i]->user, res);
                            if (range != NULL) {
                                xmlXPtrLocationSetAdd(newlocset,range);
                }
                        }
 
                        /*
                         * Cleanup
                         */
                        if (res != NULL) {
                xmlXPathReleaseObject(ctxt->context, res);
            }
                        if (ctxt->value == tmp) {
                            res = valuePop(ctxt);
                xmlXPathReleaseObject(ctxt->context, res);
                        }
                    }
        } else {    /* Not a location set */
                    CHECK_TYPE0(XPATH_NODESET);
                    obj = valuePop(ctxt);
                    oldset = obj->nodesetval;
 
                    newlocset = xmlXPtrLocationSetCreate(NULL);
 
                    if (oldset != NULL) {
                        for (i = 0; i < oldset->nodeNr; i++) {
                            /*
                             * Run the evaluation with a node list made of a single item
                             * in the nodeset.
                             */
                            ctxt->context->node = oldset->nodeTab[i];
                /*
                * OPTIMIZE TODO: Avoid recreation for every iteration.
                */
                tmp = xmlXPathCacheNewNodeSet(ctxt->context,
                ctxt->context->node);
                            valuePush(ctxt, tmp);
 
                            if (op->ch2 != -1)
                                total +=
                                    xmlXPathCompOpEval(ctxt,
                                                   &comp->steps[op->ch2]);
                if (ctxt->error != XPATH_EXPRESSION_OK) {
                                xmlXPtrFreeLocationSet(newlocset);
                                goto rangeto_error;
                }
 
                            res = valuePop(ctxt);
                            range =
                                xmlXPtrNewRangeNodeObject(oldset->nodeTab[i],
                                                      res);
                            if (range != NULL) {
                                xmlXPtrLocationSetAdd(newlocset, range);
                            }
 
                            /*
                             * Cleanup
                             */
                            if (res != NULL) {
                xmlXPathReleaseObject(ctxt->context, res);
                }
                            if (ctxt->value == tmp) {
                                res = valuePop(ctxt);
                xmlXPathReleaseObject(ctxt->context, res);
                            }
                        }
                    }
                }
 
                /*
                 * The result is used as the new evaluation set.
                 */
                valuePush(ctxt, xmlXPtrWrapLocationSet(newlocset));
rangeto_error:
        xmlXPathReleaseObject(ctxt->context, obj);
                ctxt->context->node = oldnode;
                ctxt->context->contextSize = oldcs;
                ctxt->context->proximityPosition = oldpp;
                break;
            }
#endif /* LIBXML_XPTR_LOCS_ENABLED */
        default:
            xmlGenericError(xmlGenericErrorContext,
                            "XPath: unknown precompiled operation %d\n", op->op);
            ctxt->error = XPATH_INVALID_OPERAND;
            break;
    }
 
    ctxt->context->depth -= 1;
    return (total);
}
 
static int
xmlXPathCompOpEvalToBoolean(xmlXPathParserContextPtr ctxt,
                xmlXPathStepOpPtr op,
                int isPredicate)
{
    xmlXPathObjectPtr resObj = NULL;
 
start:
    if (OP_LIMIT_EXCEEDED(ctxt, 1))
        return(0);
    /* comp = ctxt->comp; */
    switch (op->op) {
        case XPATH_OP_END:
            return (0);
    case XPATH_OP_VALUE:
        resObj = (xmlXPathObjectPtr) op->value4;
        if (isPredicate)
        return(xmlXPathEvaluatePredicateResult(ctxt, resObj));
        return(xmlXPathCastToBoolean(resObj));
    case XPATH_OP_SORT:
        /*
        * We don't need sorting for boolean results. Skip this one.
        */
            if (op->ch1 != -1) {
        op = &ctxt->comp->steps[op->ch1];
        goto start;
        }
        return(0);
    case XPATH_OP_COLLECT:
        if (op->ch1 == -1)
        return(0);
 
            xmlXPathCompOpEval(ctxt, &ctxt->comp->steps[op->ch1]);
        if (ctxt->error != XPATH_EXPRESSION_OK)
        return(-1);
 
            xmlXPathNodeCollectAndTest(ctxt, op, NULL, NULL, 1);
        if (ctxt->error != XPATH_EXPRESSION_OK)
        return(-1);
 
        resObj = valuePop(ctxt);
        if (resObj == NULL)
        return(-1);
        break;
    default:
        /*
        * Fallback to call xmlXPathCompOpEval().
        */
        xmlXPathCompOpEval(ctxt, op);
        if (ctxt->error != XPATH_EXPRESSION_OK)
        return(-1);
 
        resObj = valuePop(ctxt);
        if (resObj == NULL)
        return(-1);
        break;
    }
 
    if (resObj) {
    int res;
 
    if (resObj->type == XPATH_BOOLEAN) {
        res = resObj->boolval;
    } else if (isPredicate) {
        /*
        * For predicates a result of type "number" is handled
        * differently:
        * SPEC XPath 1.0:
        * "If the result is a number, the result will be converted
        *  to true if the number is equal to the context position
        *  and will be converted to false otherwise;"
        */
        res = xmlXPathEvaluatePredicateResult(ctxt, resObj);
    } else {
        res = xmlXPathCastToBoolean(resObj);
    }
    xmlXPathReleaseObject(ctxt->context, resObj);
    return(res);
    }
 
    return(0);
}
 
#ifdef XPATH_STREAMING
static int
xmlXPathRunStreamEval(xmlXPathContextPtr ctxt, xmlPatternPtr comp,
              xmlXPathObjectPtr *resultSeq, int toBool)
{
    int max_depth, min_depth;
    int from_root;
    int ret, depth;
    int eval_all_nodes;
    xmlNodePtr cur = NULL, limit = NULL;
    xmlStreamCtxtPtr patstream = NULL;
 
    if ((ctxt == NULL) || (comp == NULL))
        return(-1);
    max_depth = xmlPatternMaxDepth(comp);
    if (max_depth == -1)
        return(-1);
    if (max_depth == -2)
        max_depth = 10000;
    min_depth = xmlPatternMinDepth(comp);
    if (min_depth == -1)
        return(-1);
    from_root = xmlPatternFromRoot(comp);
    if (from_root < 0)
        return(-1);
#if 0
    printf("stream eval: depth %d from root %d\n", max_depth, from_root);
#endif
 
    if (! toBool) {
    if (resultSeq == NULL)
        return(-1);
    *resultSeq = xmlXPathCacheNewNodeSet(ctxt, NULL);
    if (*resultSeq == NULL)
        return(-1);
    }
 
    /*
     * handle the special cases of "/" amd "." being matched
     */
    if (min_depth == 0) {
    if (from_root) {
        /* Select "/" */
        if (toBool)
        return(1);
            /* TODO: Check memory error. */
        xmlXPathNodeSetAddUnique((*resultSeq)->nodesetval,
                             (xmlNodePtr) ctxt->doc);
    } else {
        /* Select "self::node()" */
        if (toBool)
        return(1);
            /* TODO: Check memory error. */
        xmlXPathNodeSetAddUnique((*resultSeq)->nodesetval, ctxt->node);
    }
    }
    if (max_depth == 0) {
    return(0);
    }
 
    if (from_root) {
        cur = (xmlNodePtr)ctxt->doc;
    } else if (ctxt->node != NULL) {
        switch (ctxt->node->type) {
            case XML_ELEMENT_NODE:
            case XML_DOCUMENT_NODE:
            case XML_DOCUMENT_FRAG_NODE:
            case XML_HTML_DOCUMENT_NODE:
            cur = ctxt->node;
        break;
            case XML_ATTRIBUTE_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_ENTITY_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
            case XML_NOTATION_NODE:
            case XML_DTD_NODE:
            case XML_DOCUMENT_TYPE_NODE:
            case XML_ELEMENT_DECL:
            case XML_ATTRIBUTE_DECL:
            case XML_ENTITY_DECL:
            case XML_NAMESPACE_DECL:
            case XML_XINCLUDE_START:
            case XML_XINCLUDE_END:
        break;
    }
    limit = cur;
    }
    if (cur == NULL) {
        return(0);
    }
 
    patstream = xmlPatternGetStreamCtxt(comp);
    if (patstream == NULL) {
    /*
    * QUESTION TODO: Is this an error?
    */
    return(0);
    }
 
    eval_all_nodes = xmlStreamWantsAnyNode(patstream);
 
    if (from_root) {
    ret = xmlStreamPush(patstream, NULL, NULL);
    if (ret < 0) {
    } else if (ret == 1) {
        if (toBool)
        goto return_1;
            /* TODO: Check memory error. */
        xmlXPathNodeSetAddUnique((*resultSeq)->nodesetval, cur);
    }
    }
    depth = 0;
    goto scan_children;
next_node:
    do {
        if (ctxt->opLimit != 0) {
            if (ctxt->opCount >= ctxt->opLimit) {
                xmlGenericError(xmlGenericErrorContext,
                        "XPath operation limit exceeded\n");
                xmlFreeStreamCtxt(patstream);
                return(-1);
            }
            ctxt->opCount++;
        }
 
    switch (cur->type) {
        case XML_ELEMENT_NODE:
        case XML_TEXT_NODE:
        case XML_CDATA_SECTION_NODE:
        case XML_COMMENT_NODE:
        case XML_PI_NODE:
        if (cur->type == XML_ELEMENT_NODE) {
            ret = xmlStreamPush(patstream, cur->name,
                (cur->ns ? cur->ns->href : NULL));
        } else if (eval_all_nodes)
            ret = xmlStreamPushNode(patstream, NULL, NULL, cur->type);
        else
            break;
 
        if (ret < 0) {
            /* NOP. */
        } else if (ret == 1) {
            if (toBool)
            goto return_1;
            if (xmlXPathNodeSetAddUnique((*resultSeq)->nodesetval, cur)
                < 0) {
            ctxt->lastError.domain = XML_FROM_XPATH;
            ctxt->lastError.code = XML_ERR_NO_MEMORY;
            }
        }
        if ((cur->children == NULL) || (depth >= max_depth)) {
            ret = xmlStreamPop(patstream);
            while (cur->next != NULL) {
            cur = cur->next;
            if ((cur->type != XML_ENTITY_DECL) &&
                (cur->type != XML_DTD_NODE))
                goto next_node;
            }
        }
        default:
        break;
    }
 
scan_children:
    if (cur->type == XML_NAMESPACE_DECL) break;
    if ((cur->children != NULL) && (depth < max_depth)) {
        /*
         * Do not descend on entities declarations
         */
        if (cur->children->type != XML_ENTITY_DECL) {
        cur = cur->children;
        depth++;
        /*
         * Skip DTDs
         */
        if (cur->type != XML_DTD_NODE)
            continue;
        }
    }
 
    if (cur == limit)
        break;
 
    while (cur->next != NULL) {
        cur = cur->next;
        if ((cur->type != XML_ENTITY_DECL) &&
        (cur->type != XML_DTD_NODE))
        goto next_node;
    }
 
    do {
        cur = cur->parent;
        depth--;
        if ((cur == NULL) || (cur == limit) ||
                (cur->type == XML_DOCUMENT_NODE))
            goto done;
        if (cur->type == XML_ELEMENT_NODE) {
        ret = xmlStreamPop(patstream);
        } else if ((eval_all_nodes) &&
        ((cur->type == XML_TEXT_NODE) ||
         (cur->type == XML_CDATA_SECTION_NODE) ||
         (cur->type == XML_COMMENT_NODE) ||
         (cur->type == XML_PI_NODE)))
        {
        ret = xmlStreamPop(patstream);
        }
        if (cur->next != NULL) {
        cur = cur->next;
        break;
        }
    } while (cur != NULL);
 
    } while ((cur != NULL) && (depth >= 0));
 
done:
 
    if (patstream)
    xmlFreeStreamCtxt(patstream);
    return(0);
 
return_1:
    if (patstream)
    xmlFreeStreamCtxt(patstream);
    return(1);
}
#endif /* XPATH_STREAMING */
 
static int
xmlXPathRunEval(xmlXPathParserContextPtr ctxt, int toBool)
{
    xmlXPathCompExprPtr comp;
    int oldDepth;
 
    if ((ctxt == NULL) || (ctxt->comp == NULL))
    return(-1);
 
    if (ctxt->valueTab == NULL) {
    /* Allocate the value stack */
    ctxt->valueTab = (xmlXPathObjectPtr *)
             xmlMalloc(10 * sizeof(xmlXPathObjectPtr));
    if (ctxt->valueTab == NULL) {
        xmlXPathPErrMemory(ctxt, "creating evaluation context\n");
        return(-1);
    }
    ctxt->valueNr = 0;
    ctxt->valueMax = 10;
    ctxt->value = NULL;
    }
#ifdef XPATH_STREAMING
    if (ctxt->comp->stream) {
    int res;
 
    if (toBool) {
        /*
        * Evaluation to boolean result.
        */
        res = xmlXPathRunStreamEval(ctxt->context,
        ctxt->comp->stream, NULL, 1);
        if (res != -1)
        return(res);
    } else {
        xmlXPathObjectPtr resObj = NULL;
 
        /*
        * Evaluation to a sequence.
        */
        res = xmlXPathRunStreamEval(ctxt->context,
        ctxt->comp->stream, &resObj, 0);
 
        if ((res != -1) && (resObj != NULL)) {
        valuePush(ctxt, resObj);
        return(0);
        }
        if (resObj != NULL)
        xmlXPathReleaseObject(ctxt->context, resObj);
    }
    /*
    * QUESTION TODO: This falls back to normal XPath evaluation
    * if res == -1. Is this intended?
    */
    }
#endif
    comp = ctxt->comp;
    if (comp->last < 0) {
    xmlGenericError(xmlGenericErrorContext,
        "xmlXPathRunEval: last is less than zero\n");
    return(-1);
    }
    oldDepth = ctxt->context->depth;
    if (toBool)
    return(xmlXPathCompOpEvalToBoolean(ctxt,
        &comp->steps[comp->last], 0));
    else
    xmlXPathCompOpEval(ctxt, &comp->steps[comp->last]);
    ctxt->context->depth = oldDepth;
 
    return(0);
}
 
/************************************************************************
 *                                  *
 *          Public interfaces               *
 *                                  *
 ************************************************************************/
 
int
xmlXPathEvalPredicate(xmlXPathContextPtr ctxt, xmlXPathObjectPtr res) {
    if ((ctxt == NULL) || (res == NULL)) return(0);
    switch (res->type) {
        case XPATH_BOOLEAN:
        return(res->boolval);
        case XPATH_NUMBER:
        return(res->floatval == ctxt->proximityPosition);
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
        if (res->nodesetval == NULL)
        return(0);
        return(res->nodesetval->nodeNr != 0);
        case XPATH_STRING:
        return((res->stringval != NULL) &&
               (xmlStrlen(res->stringval) != 0));
        default:
        STRANGE
    }
    return(0);
}
 
int
xmlXPathEvaluatePredicateResult(xmlXPathParserContextPtr ctxt,
                                xmlXPathObjectPtr res) {
    if ((ctxt == NULL) || (res == NULL)) return(0);
    switch (res->type) {
        case XPATH_BOOLEAN:
        return(res->boolval);
        case XPATH_NUMBER:
#if defined(__BORLANDC__) || (defined(_MSC_VER) && (_MSC_VER == 1200))
        return((res->floatval == ctxt->context->proximityPosition) &&
               (!xmlXPathIsNaN(res->floatval))); /* MSC pbm Mark Vakoc !*/
#else
        return(res->floatval == ctxt->context->proximityPosition);
#endif
        case XPATH_NODESET:
        case XPATH_XSLT_TREE:
        if (res->nodesetval == NULL)
        return(0);
        return(res->nodesetval->nodeNr != 0);
        case XPATH_STRING:
        return((res->stringval != NULL) && (res->stringval[0] != 0));
#ifdef LIBXML_XPTR_LOCS_ENABLED
    case XPATH_LOCATIONSET:{
        xmlLocationSetPtr ptr = res->user;
        if (ptr == NULL)
            return(0);
        return (ptr->locNr != 0);
        }
#endif
        default:
        STRANGE
    }
    return(0);
}
 
#ifdef XPATH_STREAMING
static xmlXPathCompExprPtr
xmlXPathTryStreamCompile(xmlXPathContextPtr ctxt, const xmlChar *str) {
    /*
     * Optimization: use streaming patterns when the XPath expression can
     * be compiled to a stream lookup
     */
    xmlPatternPtr stream;
    xmlXPathCompExprPtr comp;
    xmlDictPtr dict = NULL;
    const xmlChar **namespaces = NULL;
    xmlNsPtr ns;
    int i, j;
 
    if ((!xmlStrchr(str, '[')) && (!xmlStrchr(str, '(')) &&
        (!xmlStrchr(str, '@'))) {
    const xmlChar *tmp;
 
    /*
     * We don't try to handle expressions using the verbose axis
     * specifiers ("::"), just the simplified form at this point.
     * Additionally, if there is no list of namespaces available and
     *  there's a ":" in the expression, indicating a prefixed QName,
     *  then we won't try to compile either. xmlPatterncompile() needs
     *  to have a list of namespaces at compilation time in order to
     *  compile prefixed name tests.
     */
    tmp = xmlStrchr(str, ':');
    if ((tmp != NULL) &&
        ((ctxt == NULL) || (ctxt->nsNr == 0) || (tmp[1] == ':')))
        return(NULL);
 
    if (ctxt != NULL) {
        dict = ctxt->dict;
        if (ctxt->nsNr > 0) {
        namespaces = xmlMalloc(2 * (ctxt->nsNr + 1) * sizeof(xmlChar*));
        if (namespaces == NULL) {
            xmlXPathErrMemory(ctxt, "allocating namespaces array\n");
            return(NULL);
        }
        for (i = 0, j = 0; (j < ctxt->nsNr); j++) {
            ns = ctxt->namespaces[j];
            namespaces[i++] = ns->href;
            namespaces[i++] = ns->prefix;
        }
        namespaces[i++] = NULL;
        namespaces[i] = NULL;
        }
    }
 
    stream = xmlPatterncompile(str, dict, XML_PATTERN_XPATH, namespaces);
    if (namespaces != NULL) {
        xmlFree((xmlChar **)namespaces);
    }
    if ((stream != NULL) && (xmlPatternStreamable(stream) == 1)) {
        comp = xmlXPathNewCompExpr();
        if (comp == NULL) {
        xmlXPathErrMemory(ctxt, "allocating streamable expression\n");
            xmlFreePattern(stream);
        return(NULL);
        }
        comp->stream = stream;
        comp->dict = dict;
        if (comp->dict)
        xmlDictReference(comp->dict);
        return(comp);
    }
    xmlFreePattern(stream);
    }
    return(NULL);
}
#endif /* XPATH_STREAMING */
 
static void
xmlXPathOptimizeExpression(xmlXPathParserContextPtr pctxt,
                           xmlXPathStepOpPtr op)
{
    xmlXPathCompExprPtr comp = pctxt->comp;
    xmlXPathContextPtr ctxt;
 
    /*
    * Try to rewrite "descendant-or-self::node()/foo" to an optimized
    * internal representation.
    */
 
    if ((op->op == XPATH_OP_COLLECT /* 11 */) &&
        (op->ch1 != -1) &&
        (op->ch2 == -1 /* no predicate */))
    {
        xmlXPathStepOpPtr prevop = &comp->steps[op->ch1];
 
        if ((prevop->op == XPATH_OP_COLLECT /* 11 */) &&
            ((xmlXPathAxisVal) prevop->value ==
                AXIS_DESCENDANT_OR_SELF) &&
            (prevop->ch2 == -1) &&
            ((xmlXPathTestVal) prevop->value2 == NODE_TEST_TYPE) &&
            ((xmlXPathTypeVal) prevop->value3 == NODE_TYPE_NODE))
        {
            /*
            * This is a "descendant-or-self::node()" without predicates.
            * Try to eliminate it.
            */
 
            switch ((xmlXPathAxisVal) op->value) {
                case AXIS_CHILD:
                case AXIS_DESCENDANT:
                    /*
                    * Convert "descendant-or-self::node()/child::" or
                    * "descendant-or-self::node()/descendant::" to
                    * "descendant::"
                    */
                    op->ch1   = prevop->ch1;
                    op->value = AXIS_DESCENDANT;
                    break;
                case AXIS_SELF:
                case AXIS_DESCENDANT_OR_SELF:
                    /*
                    * Convert "descendant-or-self::node()/self::" or
                    * "descendant-or-self::node()/descendant-or-self::" to
                    * to "descendant-or-self::"
                    */
                    op->ch1   = prevop->ch1;
                    op->value = AXIS_DESCENDANT_OR_SELF;
                    break;
                default:
                    break;
            }
    }
    }
 
    /* OP_VALUE has invalid ch1. */
    if (op->op == XPATH_OP_VALUE)
        return;
 
    /* Recurse */
    ctxt = pctxt->context;
    if (ctxt != NULL) {
        if (ctxt->depth >= XPATH_MAX_RECURSION_DEPTH)
            return;
        ctxt->depth += 1;
    }
    if (op->ch1 != -1)
        xmlXPathOptimizeExpression(pctxt, &comp->steps[op->ch1]);
    if (op->ch2 != -1)
    xmlXPathOptimizeExpression(pctxt, &comp->steps[op->ch2]);
    if (ctxt != NULL)
        ctxt->depth -= 1;
}
 
xmlXPathCompExprPtr
xmlXPathCtxtCompile(xmlXPathContextPtr ctxt, const xmlChar *str) {
    xmlXPathParserContextPtr pctxt;
    xmlXPathCompExprPtr comp;
    int oldDepth = 0;
 
#ifdef XPATH_STREAMING
    comp = xmlXPathTryStreamCompile(ctxt, str);
    if (comp != NULL)
        return(comp);
#endif
 
    xmlInitParser();
 
    pctxt = xmlXPathNewParserContext(str, ctxt);
    if (pctxt == NULL)
        return NULL;
    if (ctxt != NULL)
        oldDepth = ctxt->depth;
    xmlXPathCompileExpr(pctxt, 1);
    if (ctxt != NULL)
        ctxt->depth = oldDepth;
 
    if( pctxt->error != XPATH_EXPRESSION_OK )
    {
        xmlXPathFreeParserContext(pctxt);
        return(NULL);
    }
 
    if (*pctxt->cur != 0) {
    /*
     * aleksey: in some cases this line prints *second* error message
     * (see bug #78858) and probably this should be fixed.
     * However, we are not sure that all error messages are printed
     * out in other places. It's not critical so we leave it as-is for now
     */
    xmlXPatherror(pctxt, __FILE__, __LINE__, XPATH_EXPR_ERROR);
    comp = NULL;
    } else {
    comp = pctxt->comp;
    if ((comp->nbStep > 1) && (comp->last >= 0)) {
            if (ctxt != NULL)
                oldDepth = ctxt->depth;
        xmlXPathOptimizeExpression(pctxt, &comp->steps[comp->last]);
            if (ctxt != NULL)
                ctxt->depth = oldDepth;
    }
    pctxt->comp = NULL;
    }
    xmlXPathFreeParserContext(pctxt);
 
    if (comp != NULL) {
    comp->expr = xmlStrdup(str);
    }
    return(comp);
}
 
xmlXPathCompExprPtr
xmlXPathCompile(const xmlChar *str) {
    return(xmlXPathCtxtCompile(NULL, str));
}
 
static int
xmlXPathCompiledEvalInternal(xmlXPathCompExprPtr comp,
                 xmlXPathContextPtr ctxt,
                 xmlXPathObjectPtr *resObjPtr,
                 int toBool)
{
    xmlXPathParserContextPtr pctxt;
    xmlXPathObjectPtr resObj;
#ifndef LIBXML_THREAD_ENABLED
    static int reentance = 0;
#endif
    int res;
 
    CHECK_CTXT_NEG(ctxt)
 
    if (comp == NULL)
    return(-1);
    xmlInitParser();
 
#ifndef LIBXML_THREAD_ENABLED
    reentance++;
    if (reentance > 1)
    xmlXPathDisableOptimizer = 1;
#endif
 
    pctxt = xmlXPathCompParserContext(comp, ctxt);
    if (pctxt == NULL)
        return(-1);
    res = xmlXPathRunEval(pctxt, toBool);
 
    if (pctxt->error != XPATH_EXPRESSION_OK) {
        resObj = NULL;
    } else {
        resObj = valuePop(pctxt);
        if (resObj == NULL) {
            if (!toBool)
                xmlGenericError(xmlGenericErrorContext,
                    "xmlXPathCompiledEval: No result on the stack.\n");
        } else if (pctxt->valueNr > 0) {
            xmlGenericError(xmlGenericErrorContext,
                "xmlXPathCompiledEval: %d object(s) left on the stack.\n",
                pctxt->valueNr);
        }
    }
 
    if (resObjPtr)
        *resObjPtr = resObj;
    else
        xmlXPathReleaseObject(ctxt, resObj);
 
    pctxt->comp = NULL;
    xmlXPathFreeParserContext(pctxt);
#ifndef LIBXML_THREAD_ENABLED
    reentance--;
#endif
 
    return(res);
}
 
xmlXPathObjectPtr
xmlXPathCompiledEval(xmlXPathCompExprPtr comp, xmlXPathContextPtr ctx)
{
    xmlXPathObjectPtr res = NULL;
 
    xmlXPathCompiledEvalInternal(comp, ctx, &res, 0);
    return(res);
}
 
int
xmlXPathCompiledEvalToBoolean(xmlXPathCompExprPtr comp,
                  xmlXPathContextPtr ctxt)
{
    return(xmlXPathCompiledEvalInternal(comp, ctxt, NULL, 1));
}
 
void
xmlXPathEvalExpr(xmlXPathParserContextPtr ctxt) {
#ifdef XPATH_STREAMING
    xmlXPathCompExprPtr comp;
#endif
    int oldDepth = 0;
 
    if (ctxt == NULL) return;
 
#ifdef XPATH_STREAMING
    comp = xmlXPathTryStreamCompile(ctxt->context, ctxt->base);
    if (comp != NULL) {
        if (ctxt->comp != NULL)
        xmlXPathFreeCompExpr(ctxt->comp);
        ctxt->comp = comp;
    } else
#endif
    {
        if (ctxt->context != NULL)
            oldDepth = ctxt->context->depth;
    xmlXPathCompileExpr(ctxt, 1);
        if (ctxt->context != NULL)
            ctxt->context->depth = oldDepth;
        CHECK_ERROR;
 
        /* Check for trailing characters. */
        if (*ctxt->cur != 0)
            XP_ERROR(XPATH_EXPR_ERROR);
 
    if ((ctxt->comp->nbStep > 1) && (ctxt->comp->last >= 0)) {
            if (ctxt->context != NULL)
                oldDepth = ctxt->context->depth;
        xmlXPathOptimizeExpression(ctxt,
        &ctxt->comp->steps[ctxt->comp->last]);
            if (ctxt->context != NULL)
                ctxt->context->depth = oldDepth;
        }
    }
 
    xmlXPathRunEval(ctxt, 0);
}
 
xmlXPathObjectPtr
xmlXPathEval(const xmlChar *str, xmlXPathContextPtr ctx) {
    xmlXPathParserContextPtr ctxt;
    xmlXPathObjectPtr res;
 
    CHECK_CTXT(ctx)
 
    xmlInitParser();
 
    ctxt = xmlXPathNewParserContext(str, ctx);
    if (ctxt == NULL)
        return NULL;
    xmlXPathEvalExpr(ctxt);
 
    if (ctxt->error != XPATH_EXPRESSION_OK) {
    res = NULL;
    } else {
    res = valuePop(ctxt);
        if (res == NULL) {
            xmlGenericError(xmlGenericErrorContext,
                "xmlXPathCompiledEval: No result on the stack.\n");
        } else if (ctxt->valueNr > 0) {
            xmlGenericError(xmlGenericErrorContext,
                "xmlXPathCompiledEval: %d object(s) left on the stack.\n",
                ctxt->valueNr);
        }
    }
 
    xmlXPathFreeParserContext(ctxt);
    return(res);
}
 
int
xmlXPathSetContextNode(xmlNodePtr node, xmlXPathContextPtr ctx) {
    if ((node == NULL) || (ctx == NULL))
        return(-1);
 
    if (node->doc == ctx->doc) {
        ctx->node = node;
    return(0);
    }
    return(-1);
}
 
xmlXPathObjectPtr
xmlXPathNodeEval(xmlNodePtr node, const xmlChar *str, xmlXPathContextPtr ctx) {
    if (str == NULL)
        return(NULL);
    if (xmlXPathSetContextNode(node, ctx) < 0)
        return(NULL);
    return(xmlXPathEval(str, ctx));
}
 
xmlXPathObjectPtr
xmlXPathEvalExpression(const xmlChar *str, xmlXPathContextPtr ctxt) {
    return(xmlXPathEval(str, ctxt));
}
 
/************************************************************************
 *                                  *
 *  Extra functions not pertaining to the XPath spec        *
 *                                  *
 ************************************************************************/
static void
xmlXPathEscapeUriFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr str;
    int escape_reserved;
    xmlBufPtr target;
    xmlChar *cptr;
    xmlChar escape[4];
 
    CHECK_ARITY(2);
 
    escape_reserved = xmlXPathPopBoolean(ctxt);
 
    CAST_TO_STRING;
    str = valuePop(ctxt);
 
    target = xmlBufCreate();
 
    escape[0] = '%';
    escape[3] = 0;
 
    if (target) {
    for (cptr = str->stringval; *cptr; cptr++) {
        if ((*cptr >= 'A' && *cptr <= 'Z') ||
        (*cptr >= 'a' && *cptr <= 'z') ||
        (*cptr >= '0' && *cptr <= '9') ||
        *cptr == '-' || *cptr == '_' || *cptr == '.' ||
        *cptr == '!' || *cptr == '~' || *cptr == '*' ||
        *cptr == '\''|| *cptr == '(' || *cptr == ')' ||
        (*cptr == '%' &&
         ((cptr[1] >= 'A' && cptr[1] <= 'F') ||
          (cptr[1] >= 'a' && cptr[1] <= 'f') ||
          (cptr[1] >= '0' && cptr[1] <= '9')) &&
         ((cptr[2] >= 'A' && cptr[2] <= 'F') ||
          (cptr[2] >= 'a' && cptr[2] <= 'f') ||
          (cptr[2] >= '0' && cptr[2] <= '9'))) ||
        (!escape_reserved &&
         (*cptr == ';' || *cptr == '/' || *cptr == '?' ||
          *cptr == ':' || *cptr == '@' || *cptr == '&' ||
          *cptr == '=' || *cptr == '+' || *cptr == '$' ||
          *cptr == ','))) {
        xmlBufAdd(target, cptr, 1);
        } else {
        if ((*cptr >> 4) < 10)
            escape[1] = '0' + (*cptr >> 4);
        else
            escape[1] = 'A' - 10 + (*cptr >> 4);
        if ((*cptr & 0xF) < 10)
            escape[2] = '0' + (*cptr & 0xF);
        else
            escape[2] = 'A' - 10 + (*cptr & 0xF);
 
        xmlBufAdd(target, &escape[0], 3);
        }
    }
    }
    valuePush(ctxt, xmlXPathCacheNewString(ctxt->context,
    xmlBufContent(target)));
    xmlBufFree(target);
    xmlXPathReleaseObject(ctxt->context, str);
}
 
void
xmlXPathRegisterAllFunctions(xmlXPathContextPtr ctxt)
{
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"boolean",
                         xmlXPathBooleanFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"ceiling",
                         xmlXPathCeilingFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"count",
                         xmlXPathCountFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"concat",
                         xmlXPathConcatFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"contains",
                         xmlXPathContainsFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"id",
                         xmlXPathIdFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"false",
                         xmlXPathFalseFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"floor",
                         xmlXPathFloorFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"last",
                         xmlXPathLastFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"lang",
                         xmlXPathLangFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"local-name",
                         xmlXPathLocalNameFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"not",
                         xmlXPathNotFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"name",
                         xmlXPathNameFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"namespace-uri",
                         xmlXPathNamespaceURIFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"normalize-space",
                         xmlXPathNormalizeFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"number",
                         xmlXPathNumberFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"position",
                         xmlXPathPositionFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"round",
                         xmlXPathRoundFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"string",
                         xmlXPathStringFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"string-length",
                         xmlXPathStringLengthFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"starts-with",
                         xmlXPathStartsWithFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"substring",
                         xmlXPathSubstringFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"substring-before",
                         xmlXPathSubstringBeforeFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"substring-after",
                         xmlXPathSubstringAfterFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"sum",
                         xmlXPathSumFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"true",
                         xmlXPathTrueFunction);
    xmlXPathRegisterFunc(ctxt, (const xmlChar *)"translate",
                         xmlXPathTranslateFunction);
 
    xmlXPathRegisterFuncNS(ctxt, (const xmlChar *)"escape-uri",
     (const xmlChar *)"http://www.w3.org/2002/08/xquery-functions",
                         xmlXPathEscapeUriFunction);
}
 
#endif /* LIBXML_XPATH_ENABLED */