xpointer.c

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/*
 * xpointer.c : Code to handle XML Pointer
 *
 * Base implementation was made accordingly to
 * W3C Candidate Recommendation 7 June 2000
 * http://www.w3.org/TR/2000/CR-xptr-20000607
 *
 * Added support for the element() scheme described in:
 * W3C Proposed Recommendation 13 November 2002
 * http://www.w3.org/TR/2002/PR-xptr-element-20021113/
 *
 * See Copyright for the status of this software.
 *
 * 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"
 
/*
 * TODO: better handling of error cases, the full expression should
 *       be parsed beforehand instead of a progressive evaluation
 * TODO: Access into entities references are not supported now ...
 *       need a start to be able to pop out of entities refs since
 *       parent is the entity declaration, not the ref.
 */
 
#include <string.h>
#include <libxml/xpointer.h>
#include <libxml/xmlmemory.h>
#include <libxml/parserInternals.h>
#include <libxml/uri.h>
#include <libxml/xpath.h>
#include <libxml/xpathInternals.h>
#include <libxml/xmlerror.h>
#include <libxml/globals.h>
 
#ifdef LIBXML_XPTR_ENABLED
 
/* Add support of the xmlns() xpointer scheme to initialize the namespaces */
#define XPTR_XMLNS_SCHEME
 
/* #define DEBUG_RANGES */
#ifdef DEBUG_RANGES
#ifdef LIBXML_DEBUG_ENABLED
#include <libxml/debugXML.h>
#endif
#endif
 
#define TODO                                \
    xmlGenericError(xmlGenericErrorContext,             \
        "Unimplemented block at %s:%d\n",               \
            __FILE__, __LINE__);
 
#define STRANGE                         \
    xmlGenericError(xmlGenericErrorContext,             \
        "Internal error at %s:%d\n",                \
            __FILE__, __LINE__);
 
/************************************************************************
 *                                  *
 *      Some factorized error routines              *
 *                                  *
 ************************************************************************/
 
static void
xmlXPtrErrMemory(const char *extra)
{
    __xmlRaiseError(NULL, NULL, NULL, NULL, NULL, XML_FROM_XPOINTER,
            XML_ERR_NO_MEMORY, XML_ERR_ERROR, NULL, 0, extra,
            NULL, NULL, 0, 0,
            "Memory allocation failed : %s\n", extra);
}
 
static void LIBXML_ATTR_FORMAT(3,0)
xmlXPtrErr(xmlXPathParserContextPtr ctxt, int error,
           const char * msg, const xmlChar *extra)
{
    if (ctxt != NULL)
        ctxt->error = error;
    if ((ctxt == NULL) || (ctxt->context == NULL)) {
    __xmlRaiseError(NULL, NULL, NULL,
            NULL, NULL, XML_FROM_XPOINTER, error,
            XML_ERR_ERROR, NULL, 0,
            (const char *) extra, NULL, NULL, 0, 0,
            msg, extra);
    return;
    }
 
    /* cleanup current last error */
    xmlResetError(&ctxt->context->lastError);
 
    ctxt->context->lastError.domain = XML_FROM_XPOINTER;
    ctxt->context->lastError.code = error;
    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_XPOINTER,
            error, XML_ERR_ERROR, NULL, 0,
            (const char *) extra, (const char *) ctxt->base, NULL,
            ctxt->cur - ctxt->base, 0,
            msg, extra);
    }
}
 
/************************************************************************
 *                                  *
 *      A few helper functions for child sequences      *
 *                                  *
 ************************************************************************/
#ifdef LIBXML_XPTR_LOCS_ENABLED
/* xmlXPtrAdvanceNode is a private function, but used by xinclude.c */
xmlNodePtr xmlXPtrAdvanceNode(xmlNodePtr cur, int *level);
static int
xmlXPtrGetArity(xmlNodePtr cur) {
    int i;
    if ((cur == NULL) || (cur->type == XML_NAMESPACE_DECL))
    return(-1);
    cur = cur->children;
    for (i = 0;cur != NULL;cur = cur->next) {
    if ((cur->type == XML_ELEMENT_NODE) ||
        (cur->type == XML_DOCUMENT_NODE) ||
        (cur->type == XML_HTML_DOCUMENT_NODE)) {
        i++;
    }
    }
    return(i);
}
 
static int
xmlXPtrGetIndex(xmlNodePtr cur) {
    int i;
    if ((cur == NULL) || (cur->type == XML_NAMESPACE_DECL))
    return(-1);
    for (i = 1;cur != NULL;cur = cur->prev) {
    if ((cur->type == XML_ELEMENT_NODE) ||
        (cur->type == XML_DOCUMENT_NODE) ||
        (cur->type == XML_HTML_DOCUMENT_NODE)) {
        i++;
    }
    }
    return(i);
}
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
static xmlNodePtr
xmlXPtrGetNthChild(xmlNodePtr cur, int no) {
    int i;
    if ((cur == NULL) || (cur->type == XML_NAMESPACE_DECL))
    return(cur);
    cur = cur->children;
    for (i = 0;i <= no;cur = cur->next) {
    if (cur == NULL)
        return(cur);
    if ((cur->type == XML_ELEMENT_NODE) ||
        (cur->type == XML_DOCUMENT_NODE) ||
        (cur->type == XML_HTML_DOCUMENT_NODE)) {
        i++;
        if (i == no)
        break;
    }
    }
    return(cur);
}
 
#ifdef LIBXML_XPTR_LOCS_ENABLED
/************************************************************************
 *                                  *
 *      Handling of XPointer specific types         *
 *                                  *
 ************************************************************************/
 
static int
xmlXPtrCmpPoints(xmlNodePtr node1, int index1, xmlNodePtr node2, int index2) {
    if ((node1 == NULL) || (node2 == NULL))
    return(-2);
    /*
     * a couple of optimizations which will avoid computations in most cases
     */
    if (node1 == node2) {
    if (index1 < index2)
        return(1);
    if (index1 > index2)
        return(-1);
    return(0);
    }
    return(xmlXPathCmpNodes(node1, node2));
}
 
static xmlXPathObjectPtr
xmlXPtrNewPoint(xmlNodePtr node, int indx) {
    xmlXPathObjectPtr ret;
 
    if (node == NULL)
    return(NULL);
    if (indx < 0)
    return(NULL);
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPtrErrMemory("allocating point");
    return(NULL);
    }
    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
    ret->type = XPATH_POINT;
    ret->user = (void *) node;
    ret->index = indx;
    return(ret);
}
 
static void
xmlXPtrRangeCheckOrder(xmlXPathObjectPtr range) {
    int tmp;
    xmlNodePtr tmp2;
    if (range == NULL)
    return;
    if (range->type != XPATH_RANGE)
    return;
    if (range->user2 == NULL)
    return;
    tmp = xmlXPtrCmpPoints(range->user, range->index,
                         range->user2, range->index2);
    if (tmp == -1) {
    tmp2 = range->user;
    range->user = range->user2;
    range->user2 = tmp2;
    tmp = range->index;
    range->index = range->index2;
    range->index2 = tmp;
    }
}
 
static int
xmlXPtrRangesEqual(xmlXPathObjectPtr range1, xmlXPathObjectPtr range2) {
    if (range1 == range2)
    return(1);
    if ((range1 == NULL) || (range2 == NULL))
    return(0);
    if (range1->type != range2->type)
    return(0);
    if (range1->type != XPATH_RANGE)
    return(0);
    if (range1->user != range2->user)
    return(0);
    if (range1->index != range2->index)
    return(0);
    if (range1->user2 != range2->user2)
    return(0);
    if (range1->index2 != range2->index2)
    return(0);
    return(1);
}
 
static xmlXPathObjectPtr
xmlXPtrNewRangeInternal(xmlNodePtr start, int startindex,
                        xmlNodePtr end, int endindex) {
    xmlXPathObjectPtr ret;
 
    /*
     * Namespace nodes must be copied (see xmlXPathNodeSetDupNs).
     * Disallow them for now.
     */
    if ((start != NULL) && (start->type == XML_NAMESPACE_DECL))
    return(NULL);
    if ((end != NULL) && (end->type == XML_NAMESPACE_DECL))
    return(NULL);
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPtrErrMemory("allocating range");
    return(NULL);
    }
    memset(ret, 0, sizeof(xmlXPathObject));
    ret->type = XPATH_RANGE;
    ret->user = start;
    ret->index = startindex;
    ret->user2 = end;
    ret->index2 = endindex;
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrNewRange(xmlNodePtr start, int startindex,
            xmlNodePtr end, int endindex) {
    xmlXPathObjectPtr ret;
 
    if (start == NULL)
    return(NULL);
    if (end == NULL)
    return(NULL);
    if (startindex < 0)
    return(NULL);
    if (endindex < 0)
    return(NULL);
 
    ret = xmlXPtrNewRangeInternal(start, startindex, end, endindex);
    xmlXPtrRangeCheckOrder(ret);
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrNewRangePoints(xmlXPathObjectPtr start, xmlXPathObjectPtr end) {
    xmlXPathObjectPtr ret;
 
    if (start == NULL)
    return(NULL);
    if (end == NULL)
    return(NULL);
    if (start->type != XPATH_POINT)
    return(NULL);
    if (end->type != XPATH_POINT)
    return(NULL);
 
    ret = xmlXPtrNewRangeInternal(start->user, start->index, end->user,
                                  end->index);
    xmlXPtrRangeCheckOrder(ret);
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrNewRangePointNode(xmlXPathObjectPtr start, xmlNodePtr end) {
    xmlXPathObjectPtr ret;
 
    if (start == NULL)
    return(NULL);
    if (end == NULL)
    return(NULL);
    if (start->type != XPATH_POINT)
    return(NULL);
 
    ret = xmlXPtrNewRangeInternal(start->user, start->index, end, -1);
    xmlXPtrRangeCheckOrder(ret);
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrNewRangeNodePoint(xmlNodePtr start, xmlXPathObjectPtr end) {
    xmlXPathObjectPtr ret;
 
    if (start == NULL)
    return(NULL);
    if (end == NULL)
    return(NULL);
    if (end->type != XPATH_POINT)
    return(NULL);
 
    ret = xmlXPtrNewRangeInternal(start, -1, end->user, end->index);
    xmlXPtrRangeCheckOrder(ret);
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrNewRangeNodes(xmlNodePtr start, xmlNodePtr end) {
    xmlXPathObjectPtr ret;
 
    if (start == NULL)
    return(NULL);
    if (end == NULL)
    return(NULL);
 
    ret = xmlXPtrNewRangeInternal(start, -1, end, -1);
    xmlXPtrRangeCheckOrder(ret);
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrNewCollapsedRange(xmlNodePtr start) {
    xmlXPathObjectPtr ret;
 
    if (start == NULL)
    return(NULL);
 
    ret = xmlXPtrNewRangeInternal(start, -1, NULL, -1);
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrNewRangeNodeObject(xmlNodePtr start, xmlXPathObjectPtr end) {
    xmlNodePtr endNode;
    int endIndex;
    xmlXPathObjectPtr ret;
 
    if (start == NULL)
    return(NULL);
    if (end == NULL)
    return(NULL);
    switch (end->type) {
    case XPATH_POINT:
        endNode = end->user;
        endIndex = end->index;
        break;
    case XPATH_RANGE:
        endNode = end->user2;
        endIndex = end->index2;
        break;
    case XPATH_NODESET:
        /*
         * Empty set ...
         */
        if ((end->nodesetval == NULL) || (end->nodesetval->nodeNr <= 0))
        return(NULL);
        endNode = end->nodesetval->nodeTab[end->nodesetval->nodeNr - 1];
        endIndex = -1;
        break;
    default:
        /* TODO */
        return(NULL);
    }
 
    ret = xmlXPtrNewRangeInternal(start, -1, endNode, endIndex);
    xmlXPtrRangeCheckOrder(ret);
    return(ret);
}
 
#define XML_RANGESET_DEFAULT    10
 
xmlLocationSetPtr
xmlXPtrLocationSetCreate(xmlXPathObjectPtr val) {
    xmlLocationSetPtr ret;
 
    ret = (xmlLocationSetPtr) xmlMalloc(sizeof(xmlLocationSet));
    if (ret == NULL) {
        xmlXPtrErrMemory("allocating locationset");
    return(NULL);
    }
    memset(ret, 0 , (size_t) sizeof(xmlLocationSet));
    if (val != NULL) {
        ret->locTab = (xmlXPathObjectPtr *) xmlMalloc(XML_RANGESET_DEFAULT *
                         sizeof(xmlXPathObjectPtr));
    if (ret->locTab == NULL) {
        xmlXPtrErrMemory("allocating locationset");
        xmlFree(ret);
        return(NULL);
    }
    memset(ret->locTab, 0 ,
           XML_RANGESET_DEFAULT * (size_t) sizeof(xmlXPathObjectPtr));
        ret->locMax = XML_RANGESET_DEFAULT;
    ret->locTab[ret->locNr++] = val;
    }
    return(ret);
}
 
void
xmlXPtrLocationSetAdd(xmlLocationSetPtr cur, xmlXPathObjectPtr val) {
    int i;
 
    if ((cur == NULL) || (val == NULL)) return;
 
    /*
     * check against doublons
     */
    for (i = 0;i < cur->locNr;i++) {
    if (xmlXPtrRangesEqual(cur->locTab[i], val)) {
        xmlXPathFreeObject(val);
        return;
    }
    }
 
    /*
     * grow the locTab if needed
     */
    if (cur->locMax == 0) {
        cur->locTab = (xmlXPathObjectPtr *) xmlMalloc(XML_RANGESET_DEFAULT *
                         sizeof(xmlXPathObjectPtr));
    if (cur->locTab == NULL) {
        xmlXPtrErrMemory("adding location to set");
        return;
    }
    memset(cur->locTab, 0 ,
           XML_RANGESET_DEFAULT * (size_t) sizeof(xmlXPathObjectPtr));
        cur->locMax = XML_RANGESET_DEFAULT;
    } else if (cur->locNr == cur->locMax) {
        xmlXPathObjectPtr *temp;
 
        cur->locMax *= 2;
    temp = (xmlXPathObjectPtr *) xmlRealloc(cur->locTab, cur->locMax *
                      sizeof(xmlXPathObjectPtr));
    if (temp == NULL) {
        xmlXPtrErrMemory("adding location to set");
        return;
    }
    cur->locTab = temp;
    }
    cur->locTab[cur->locNr++] = val;
}
 
xmlLocationSetPtr
xmlXPtrLocationSetMerge(xmlLocationSetPtr val1, xmlLocationSetPtr val2) {
    int i;
 
    if (val1 == NULL) return(NULL);
    if (val2 == NULL) return(val1);
 
    /*
     * !!!!! this can be optimized a lot, knowing that both
     *       val1 and val2 already have unicity of their values.
     */
 
    for (i = 0;i < val2->locNr;i++)
        xmlXPtrLocationSetAdd(val1, val2->locTab[i]);
 
    return(val1);
}
 
void
xmlXPtrLocationSetDel(xmlLocationSetPtr cur, xmlXPathObjectPtr val) {
    int i;
 
    if (cur == NULL) return;
    if (val == NULL) return;
 
    /*
     * check against doublons
     */
    for (i = 0;i < cur->locNr;i++)
        if (cur->locTab[i] == val) break;
 
    if (i >= cur->locNr) {
#ifdef DEBUG
        xmlGenericError(xmlGenericErrorContext,
            "xmlXPtrLocationSetDel: Range wasn't found in RangeList\n");
#endif
        return;
    }
    cur->locNr--;
    for (;i < cur->locNr;i++)
        cur->locTab[i] = cur->locTab[i + 1];
    cur->locTab[cur->locNr] = NULL;
}
 
void
xmlXPtrLocationSetRemove(xmlLocationSetPtr cur, int val) {
    if (cur == NULL) return;
    if (val >= cur->locNr) return;
    cur->locNr--;
    for (;val < cur->locNr;val++)
        cur->locTab[val] = cur->locTab[val + 1];
    cur->locTab[cur->locNr] = NULL;
}
 
void
xmlXPtrFreeLocationSet(xmlLocationSetPtr obj) {
    int i;
 
    if (obj == NULL) return;
    if (obj->locTab != NULL) {
    for (i = 0;i < obj->locNr; i++) {
            xmlXPathFreeObject(obj->locTab[i]);
    }
    xmlFree(obj->locTab);
    }
    xmlFree(obj);
}
 
xmlXPathObjectPtr
xmlXPtrNewLocationSetNodes(xmlNodePtr start, xmlNodePtr end) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPtrErrMemory("allocating locationset");
    return(NULL);
    }
    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
    ret->type = XPATH_LOCATIONSET;
    if (end == NULL)
    ret->user = xmlXPtrLocationSetCreate(xmlXPtrNewCollapsedRange(start));
    else
    ret->user = xmlXPtrLocationSetCreate(xmlXPtrNewRangeNodes(start,end));
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrNewLocationSetNodeSet(xmlNodeSetPtr set) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPtrErrMemory("allocating locationset");
    return(NULL);
    }
    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
    ret->type = XPATH_LOCATIONSET;
    if (set != NULL) {
    int i;
    xmlLocationSetPtr newset;
 
    newset = xmlXPtrLocationSetCreate(NULL);
    if (newset == NULL)
        return(ret);
 
    for (i = 0;i < set->nodeNr;i++)
        xmlXPtrLocationSetAdd(newset,
                xmlXPtrNewCollapsedRange(set->nodeTab[i]));
 
    ret->user = (void *) newset;
    }
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrWrapLocationSet(xmlLocationSetPtr val) {
    xmlXPathObjectPtr ret;
 
    ret = (xmlXPathObjectPtr) xmlMalloc(sizeof(xmlXPathObject));
    if (ret == NULL) {
        xmlXPtrErrMemory("allocating locationset");
    return(NULL);
    }
    memset(ret, 0 , (size_t) sizeof(xmlXPathObject));
    ret->type = XPATH_LOCATIONSET;
    ret->user = (void *) val;
    return(ret);
}
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
/************************************************************************
 *                                  *
 *          The parser                  *
 *                                  *
 ************************************************************************/
 
static void xmlXPtrEvalChildSeq(xmlXPathParserContextPtr ctxt, xmlChar *name);
 
/*
 * 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     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 SKIP_BLANKS                         \
    while (IS_BLANK_CH(*(ctxt->cur))) NEXT
 
#define CURRENT (*ctxt->cur)
#define NEXT ((*ctxt->cur) ?  ctxt->cur++: ctxt->cur)
 
/*
 * xmlXPtrGetChildNo:
 * @ctxt:  the XPointer Parser context
 * @index:  the child number
 *
 * Move the current node of the nodeset on the stack to the
 * given child if found
 */
static void
xmlXPtrGetChildNo(xmlXPathParserContextPtr ctxt, int indx) {
    xmlNodePtr cur = NULL;
    xmlXPathObjectPtr obj;
    xmlNodeSetPtr oldset;
 
    CHECK_TYPE(XPATH_NODESET);
    obj = valuePop(ctxt);
    oldset = obj->nodesetval;
    if ((indx <= 0) || (oldset == NULL) || (oldset->nodeNr != 1)) {
    xmlXPathFreeObject(obj);
    valuePush(ctxt, xmlXPathNewNodeSet(NULL));
    return;
    }
    cur = xmlXPtrGetNthChild(oldset->nodeTab[0], indx);
    if (cur == NULL) {
    xmlXPathFreeObject(obj);
    valuePush(ctxt, xmlXPathNewNodeSet(NULL));
    return;
    }
    oldset->nodeTab[0] = cur;
    valuePush(ctxt, obj);
}
 
static void
xmlXPtrEvalXPtrPart(xmlXPathParserContextPtr ctxt, xmlChar *name) {
    xmlChar *buffer, *cur;
    int len;
    int level;
 
    if (name == NULL)
    name = xmlXPathParseName(ctxt);
    if (name == NULL)
    XP_ERROR(XPATH_EXPR_ERROR);
 
    if (CUR != '(') {
        xmlFree(name);
    XP_ERROR(XPATH_EXPR_ERROR);
    }
    NEXT;
    level = 1;
 
    len = xmlStrlen(ctxt->cur);
    len++;
    buffer = (xmlChar *) xmlMallocAtomic(len * sizeof (xmlChar));
    if (buffer == NULL) {
        xmlXPtrErrMemory("allocating buffer");
        xmlFree(name);
    return;
    }
 
    cur = buffer;
    while (CUR != 0) {
    if (CUR == ')') {
        level--;
        if (level == 0) {
        NEXT;
        break;
        }
    } else if (CUR == '(') {
        level++;
    } else if (CUR == '^') {
            if ((NXT(1) == ')') || (NXT(1) == '(') || (NXT(1) == '^')) {
                NEXT;
            }
    }
        *cur++ = CUR;
    NEXT;
    }
    *cur = 0;
 
    if ((level != 0) && (CUR == 0)) {
        xmlFree(name);
    xmlFree(buffer);
    XP_ERROR(XPTR_SYNTAX_ERROR);
    }
 
    if (xmlStrEqual(name, (xmlChar *) "xpointer") ||
        xmlStrEqual(name, (xmlChar *) "xpath1")) {
    const xmlChar *oldBase = ctxt->base;
    const xmlChar *oldCur = ctxt->cur;
 
    ctxt->cur = ctxt->base = buffer;
    /*
     * To evaluate an xpointer scheme element (4.3) we need:
     *   context initialized to the root
     *   context position initialized to 1
     *   context size initialized to 1
     */
    ctxt->context->node = (xmlNodePtr)ctxt->context->doc;
    ctxt->context->proximityPosition = 1;
    ctxt->context->contextSize = 1;
#ifdef LIBXML_XPTR_LOCS_ENABLED
        ctxt->xptr = xmlStrEqual(name, (xmlChar *) "xpointer");
#endif
    xmlXPathEvalExpr(ctxt);
    ctxt->base = oldBase;
        ctxt->cur = oldCur;
    } else if (xmlStrEqual(name, (xmlChar *) "element")) {
    const xmlChar *oldBase = ctxt->base;
    const xmlChar *oldCur = ctxt->cur;
    xmlChar *name2;
 
    ctxt->cur = ctxt->base = buffer;
    if (buffer[0] == '/') {
        xmlXPathRoot(ctxt);
        xmlXPtrEvalChildSeq(ctxt, NULL);
    } else {
        name2 = xmlXPathParseName(ctxt);
        if (name2 == NULL) {
                ctxt->base = oldBase;
                ctxt->cur = oldCur;
        xmlFree(buffer);
                xmlFree(name);
        XP_ERROR(XPATH_EXPR_ERROR);
        }
        xmlXPtrEvalChildSeq(ctxt, name2);
    }
    ctxt->base = oldBase;
        ctxt->cur = oldCur;
#ifdef XPTR_XMLNS_SCHEME
    } else if (xmlStrEqual(name, (xmlChar *) "xmlns")) {
    const xmlChar *oldBase = ctxt->base;
    const xmlChar *oldCur = ctxt->cur;
    xmlChar *prefix;
 
    ctxt->cur = ctxt->base = buffer;
        prefix = xmlXPathParseNCName(ctxt);
    if (prefix == NULL) {
            ctxt->base = oldBase;
            ctxt->cur = oldCur;
        xmlFree(buffer);
        xmlFree(name);
        XP_ERROR(XPTR_SYNTAX_ERROR);
    }
    SKIP_BLANKS;
    if (CUR != '=') {
            ctxt->base = oldBase;
            ctxt->cur = oldCur;
        xmlFree(prefix);
        xmlFree(buffer);
        xmlFree(name);
        XP_ERROR(XPTR_SYNTAX_ERROR);
    }
    NEXT;
    SKIP_BLANKS;
 
    xmlXPathRegisterNs(ctxt->context, prefix, ctxt->cur);
        ctxt->base = oldBase;
        ctxt->cur = oldCur;
    xmlFree(prefix);
#endif /* XPTR_XMLNS_SCHEME */
    } else {
        xmlXPtrErr(ctxt, XML_XPTR_UNKNOWN_SCHEME,
           "unsupported scheme '%s'\n", name);
    }
    xmlFree(buffer);
    xmlFree(name);
}
 
static void
xmlXPtrEvalFullXPtr(xmlXPathParserContextPtr ctxt, xmlChar *name) {
    if (name == NULL)
    name = xmlXPathParseName(ctxt);
    if (name == NULL)
    XP_ERROR(XPATH_EXPR_ERROR);
    while (name != NULL) {
    ctxt->error = XPATH_EXPRESSION_OK;
    xmlXPtrEvalXPtrPart(ctxt, name);
 
    /* in case of syntax error, break here */
    if ((ctxt->error != XPATH_EXPRESSION_OK) &&
            (ctxt->error != XML_XPTR_UNKNOWN_SCHEME))
        return;
 
    /*
     * If the returned value is a non-empty nodeset
     * or location set, return here.
     */
    if (ctxt->value != NULL) {
        xmlXPathObjectPtr obj = ctxt->value;
 
        switch (obj->type) {
#ifdef LIBXML_XPTR_LOCS_ENABLED
        case XPATH_LOCATIONSET: {
            xmlLocationSetPtr loc = ctxt->value->user;
            if ((loc != NULL) && (loc->locNr > 0))
            return;
            break;
        }
#endif
        case XPATH_NODESET: {
            xmlNodeSetPtr loc = ctxt->value->nodesetval;
            if ((loc != NULL) && (loc->nodeNr > 0))
            return;
            break;
        }
        default:
            break;
        }
 
        /*
         * Evaluating to improper values is equivalent to
         * a sub-resource error, clean-up the stack
         */
        do {
        obj = valuePop(ctxt);
        if (obj != NULL) {
            xmlXPathFreeObject(obj);
        }
        } while (obj != NULL);
    }
 
    /*
     * Is there another XPointer part.
     */
    SKIP_BLANKS;
    name = xmlXPathParseName(ctxt);
    }
}
 
static void
xmlXPtrEvalChildSeq(xmlXPathParserContextPtr ctxt, xmlChar *name) {
    /*
     * XPointer don't allow by syntax to address in multirooted trees
     * this might prove useful in some cases, warn about it.
     */
    if ((name == NULL) && (CUR == '/') && (NXT(1) != '1')) {
        xmlXPtrErr(ctxt, XML_XPTR_CHILDSEQ_START,
           "warning: ChildSeq not starting by /1\n", NULL);
    }
 
    if (name != NULL) {
    valuePush(ctxt, xmlXPathNewString(name));
    xmlFree(name);
    xmlXPathIdFunction(ctxt, 1);
    CHECK_ERROR;
    }
 
    while (CUR == '/') {
    int child = 0, overflow = 0;
    NEXT;
 
    while ((CUR >= '0') && (CUR <= '9')) {
            int d = CUR - '0';
            if (child > INT_MAX / 10)
                overflow = 1;
            else
                child *= 10;
            if (child > INT_MAX - d)
                overflow = 1;
            else
                child += d;
        NEXT;
    }
        if (overflow)
            child = 0;
    xmlXPtrGetChildNo(ctxt, child);
    }
}
 
 
static void
xmlXPtrEvalXPointer(xmlXPathParserContextPtr ctxt) {
    if (ctxt->valueTab == NULL) {
    /* Allocate the value stack */
    ctxt->valueTab = (xmlXPathObjectPtr *)
             xmlMalloc(10 * sizeof(xmlXPathObjectPtr));
    if (ctxt->valueTab == NULL) {
        xmlXPtrErrMemory("allocating evaluation context");
        return;
    }
    ctxt->valueNr = 0;
    ctxt->valueMax = 10;
    ctxt->value = NULL;
    ctxt->valueFrame = 0;
    }
    SKIP_BLANKS;
    if (CUR == '/') {
    xmlXPathRoot(ctxt);
        xmlXPtrEvalChildSeq(ctxt, NULL);
    } else {
    xmlChar *name;
 
    name = xmlXPathParseName(ctxt);
    if (name == NULL)
        XP_ERROR(XPATH_EXPR_ERROR);
    if (CUR == '(') {
        xmlXPtrEvalFullXPtr(ctxt, name);
        /* Short evaluation */
        return;
    } else {
        /* this handle both Bare Names and Child Sequences */
        xmlXPtrEvalChildSeq(ctxt, name);
    }
    }
    SKIP_BLANKS;
    if (CUR != 0)
    XP_ERROR(XPATH_EXPR_ERROR);
}
 
 
/************************************************************************
 *                                  *
 *          General routines                *
 *                                  *
 ************************************************************************/
 
#ifdef LIBXML_XPTR_LOCS_ENABLED
static
void xmlXPtrStringRangeFunction(xmlXPathParserContextPtr ctxt, int nargs);
static
void xmlXPtrStartPointFunction(xmlXPathParserContextPtr ctxt, int nargs);
static
void xmlXPtrEndPointFunction(xmlXPathParserContextPtr ctxt, int nargs);
static
void xmlXPtrHereFunction(xmlXPathParserContextPtr ctxt, int nargs);
static
void xmlXPtrOriginFunction(xmlXPathParserContextPtr ctxt, int nargs);
static
void xmlXPtrRangeInsideFunction(xmlXPathParserContextPtr ctxt, int nargs);
static
void xmlXPtrRangeFunction(xmlXPathParserContextPtr ctxt, int nargs);
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
xmlXPathContextPtr
xmlXPtrNewContext(xmlDocPtr doc, xmlNodePtr here, xmlNodePtr origin) {
    xmlXPathContextPtr ret;
    (void) here;
    (void) origin;
 
    ret = xmlXPathNewContext(doc);
    if (ret == NULL)
    return(ret);
#ifdef LIBXML_XPTR_LOCS_ENABLED
    ret->xptr = 1;
    ret->here = here;
    ret->origin = origin;
 
    xmlXPathRegisterFunc(ret, (xmlChar *)"range",
                     xmlXPtrRangeFunction);
    xmlXPathRegisterFunc(ret, (xmlChar *)"range-inside",
                     xmlXPtrRangeInsideFunction);
    xmlXPathRegisterFunc(ret, (xmlChar *)"string-range",
                     xmlXPtrStringRangeFunction);
    xmlXPathRegisterFunc(ret, (xmlChar *)"start-point",
                     xmlXPtrStartPointFunction);
    xmlXPathRegisterFunc(ret, (xmlChar *)"end-point",
                     xmlXPtrEndPointFunction);
    xmlXPathRegisterFunc(ret, (xmlChar *)"here",
                     xmlXPtrHereFunction);
    xmlXPathRegisterFunc(ret, (xmlChar *)" origin",
                     xmlXPtrOriginFunction);
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
    return(ret);
}
 
xmlXPathObjectPtr
xmlXPtrEval(const xmlChar *str, xmlXPathContextPtr ctx) {
    xmlXPathParserContextPtr ctxt;
    xmlXPathObjectPtr res = NULL, tmp;
    xmlXPathObjectPtr init = NULL;
    int stack = 0;
 
    xmlInitParser();
 
    if ((ctx == NULL) || (str == NULL))
    return(NULL);
 
    ctxt = xmlXPathNewParserContext(str, ctx);
    if (ctxt == NULL)
    return(NULL);
    xmlXPtrEvalXPointer(ctxt);
 
    if ((ctxt->value != NULL) &&
#ifdef LIBXML_XPTR_LOCS_ENABLED
    (ctxt->value->type != XPATH_LOCATIONSET) &&
#endif
    (ctxt->value->type != XPATH_NODESET)) {
        xmlXPtrErr(ctxt, XML_XPTR_EVAL_FAILED,
        "xmlXPtrEval: evaluation failed to return a node set\n",
           NULL);
    } else {
    res = valuePop(ctxt);
    }
 
    do {
        tmp = valuePop(ctxt);
    if (tmp != NULL) {
        if (tmp != init) {
        if (tmp->type == XPATH_NODESET) {
            /*
             * Evaluation may push a root nodeset which is unused
             */
            xmlNodeSetPtr set;
            set = tmp->nodesetval;
            if ((set == NULL) || (set->nodeNr != 1) ||
            (set->nodeTab[0] != (xmlNodePtr) ctx->doc))
            stack++;
        } else
            stack++;
        }
        xmlXPathFreeObject(tmp);
        }
    } while (tmp != NULL);
    if (stack != 0) {
        xmlXPtrErr(ctxt, XML_XPTR_EXTRA_OBJECTS,
           "xmlXPtrEval: object(s) left on the eval stack\n",
           NULL);
    }
    if (ctxt->error != XPATH_EXPRESSION_OK) {
    xmlXPathFreeObject(res);
    res = NULL;
    }
 
    xmlXPathFreeParserContext(ctxt);
    return(res);
}
 
#ifdef LIBXML_XPTR_LOCS_ENABLED
static xmlNodePtr
xmlXPtrBuildRangeNodeList(xmlXPathObjectPtr range) {
    /* pointers to generated nodes */
    xmlNodePtr list = NULL, last = NULL, parent = NULL, tmp;
    /* pointers to traversal nodes */
    xmlNodePtr start, cur, end;
    int index1, index2;
 
    if (range == NULL)
    return(NULL);
    if (range->type != XPATH_RANGE)
    return(NULL);
    start = (xmlNodePtr) range->user;
 
    if ((start == NULL) || (start->type == XML_NAMESPACE_DECL))
    return(NULL);
    end = range->user2;
    if (end == NULL)
    return(xmlCopyNode(start, 1));
    if (end->type == XML_NAMESPACE_DECL)
        return(NULL);
 
    cur = start;
    index1 = range->index;
    index2 = range->index2;
    while (cur != NULL) {
    if (cur == end) {
        if (cur->type == XML_TEXT_NODE) {
        const xmlChar *content = cur->content;
        int len;
 
        if (content == NULL) {
            tmp = xmlNewTextLen(NULL, 0);
        } else {
            len = index2;
            if ((cur == start) && (index1 > 1)) {
            content += (index1 - 1);
            len -= (index1 - 1);
            index1 = 0;
            } else {
            len = index2;
            }
            tmp = xmlNewTextLen(content, len);
        }
        /* single sub text node selection */
        if (list == NULL)
            return(tmp);
        /* prune and return full set */
        if (last != NULL)
            xmlAddNextSibling(last, tmp);
        else
            xmlAddChild(parent, tmp);
        return(list);
        } else {
        tmp = xmlCopyNode(cur, 0);
        if (list == NULL) {
            list = tmp;
            parent = tmp;
        } else {
            if (last != NULL)
            parent = xmlAddNextSibling(last, tmp);
            else
            parent = xmlAddChild(parent, tmp);
        }
        last = NULL;
 
        if (index2 > 1) {
            end = xmlXPtrGetNthChild(cur, index2 - 1);
            index2 = 0;
        }
        if ((cur == start) && (index1 > 1)) {
            cur = xmlXPtrGetNthChild(cur, index1 - 1);
            index1 = 0;
        } else {
            cur = cur->children;
        }
        /*
         * Now gather the remaining nodes from cur to end
         */
        continue; /* while */
        }
    } else if ((cur == start) &&
           (list == NULL) /* looks superfluous but ... */ ) {
        if ((cur->type == XML_TEXT_NODE) ||
        (cur->type == XML_CDATA_SECTION_NODE)) {
        const xmlChar *content = cur->content;
 
        if (content == NULL) {
            tmp = xmlNewTextLen(NULL, 0);
        } else {
            if (index1 > 1) {
            content += (index1 - 1);
            }
            tmp = xmlNewText(content);
        }
        last = list = tmp;
        } else {
        if ((cur == start) && (index1 > 1)) {
            tmp = xmlCopyNode(cur, 0);
            list = tmp;
            parent = tmp;
            last = NULL;
            cur = xmlXPtrGetNthChild(cur, index1 - 1);
            index1 = 0;
            /*
             * Now gather the remaining nodes from cur to end
             */
            continue; /* while */
        }
        tmp = xmlCopyNode(cur, 1);
        list = tmp;
        parent = NULL;
        last = tmp;
        }
    } else {
        tmp = NULL;
        switch (cur->type) {
        case XML_DTD_NODE:
        case XML_ELEMENT_DECL:
        case XML_ATTRIBUTE_DECL:
        case XML_ENTITY_NODE:
            /* Do not copy DTD information */
            break;
        case XML_ENTITY_DECL:
            TODO /* handle crossing entities -> stack needed */
            break;
        case XML_XINCLUDE_START:
        case XML_XINCLUDE_END:
            /* don't consider it part of the tree content */
            break;
        case XML_ATTRIBUTE_NODE:
            /* Humm, should not happen ! */
            STRANGE
            break;
        default:
            tmp = xmlCopyNode(cur, 1);
            break;
        }
        if (tmp != NULL) {
        if ((list == NULL) || ((last == NULL) && (parent == NULL)))  {
            STRANGE
            return(NULL);
        }
        if (last != NULL)
            xmlAddNextSibling(last, tmp);
        else {
            last = xmlAddChild(parent, tmp);
        }
        }
    }
    /*
     * Skip to next node in document order
     */
    if ((list == NULL) || ((last == NULL) && (parent == NULL)))  {
        STRANGE
        return(NULL);
    }
    cur = xmlXPtrAdvanceNode(cur, NULL);
    }
    return(list);
}
 
xmlNodePtr
xmlXPtrBuildNodeList(xmlXPathObjectPtr obj) {
    xmlNodePtr list = NULL, last = NULL;
    int i;
 
    if (obj == NULL)
    return(NULL);
    switch (obj->type) {
        case XPATH_NODESET: {
        xmlNodeSetPtr set = obj->nodesetval;
        if (set == NULL)
        return(NULL);
        for (i = 0;i < set->nodeNr;i++) {
        if (set->nodeTab[i] == NULL)
            continue;
        switch (set->nodeTab[i]->type) {
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ELEMENT_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_ENTITY_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
            case XML_DOCUMENT_NODE:
            case XML_HTML_DOCUMENT_NODE:
            case XML_XINCLUDE_START:
            case XML_XINCLUDE_END:
            break;
            case XML_ATTRIBUTE_NODE:
            case XML_NAMESPACE_DECL:
            case XML_DOCUMENT_TYPE_NODE:
            case XML_DOCUMENT_FRAG_NODE:
            case XML_NOTATION_NODE:
            case XML_DTD_NODE:
            case XML_ELEMENT_DECL:
            case XML_ATTRIBUTE_DECL:
            case XML_ENTITY_DECL:
            continue; /* for */
        }
        if (last == NULL)
            list = last = xmlCopyNode(set->nodeTab[i], 1);
        else {
            xmlAddNextSibling(last, xmlCopyNode(set->nodeTab[i], 1));
            if (last->next != NULL)
            last = last->next;
        }
        }
        break;
    }
    case XPATH_LOCATIONSET: {
        xmlLocationSetPtr set = (xmlLocationSetPtr) obj->user;
        if (set == NULL)
        return(NULL);
        for (i = 0;i < set->locNr;i++) {
        if (last == NULL)
            list = last = xmlXPtrBuildNodeList(set->locTab[i]);
        else
            xmlAddNextSibling(last,
                xmlXPtrBuildNodeList(set->locTab[i]));
        if (last != NULL) {
            while (last->next != NULL)
            last = last->next;
        }
        }
        break;
    }
    case XPATH_RANGE:
        return(xmlXPtrBuildRangeNodeList(obj));
    case XPATH_POINT:
        return(xmlCopyNode(obj->user, 0));
    default:
        break;
    }
    return(list);
}
 
/************************************************************************
 *                                  *
 *          XPointer functions              *
 *                                  *
 ************************************************************************/
 
static int
xmlXPtrNbLocChildren(xmlNodePtr node) {
    int ret = 0;
    if (node == NULL)
    return(-1);
    switch (node->type) {
        case XML_HTML_DOCUMENT_NODE:
        case XML_DOCUMENT_NODE:
        case XML_ELEMENT_NODE:
        node = node->children;
        while (node != NULL) {
        if (node->type == XML_ELEMENT_NODE)
            ret++;
        node = node->next;
        }
        break;
        case XML_ATTRIBUTE_NODE:
        return(-1);
 
        case XML_PI_NODE:
        case XML_COMMENT_NODE:
        case XML_TEXT_NODE:
        case XML_CDATA_SECTION_NODE:
        case XML_ENTITY_REF_NODE:
        ret = xmlStrlen(node->content);
        break;
    default:
        return(-1);
    }
    return(ret);
}
 
static void
xmlXPtrHereFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(0);
 
    if (ctxt->context->here == NULL)
    XP_ERROR(XPTR_SYNTAX_ERROR);
 
    valuePush(ctxt, xmlXPtrNewLocationSetNodes(ctxt->context->here, NULL));
}
 
static void
xmlXPtrOriginFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    CHECK_ARITY(0);
 
    if (ctxt->context->origin == NULL)
    XP_ERROR(XPTR_SYNTAX_ERROR);
 
    valuePush(ctxt, xmlXPtrNewLocationSetNodes(ctxt->context->origin, NULL));
}
 
static void
xmlXPtrStartPointFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr tmp, obj, point;
    xmlLocationSetPtr newset = NULL;
    xmlLocationSetPtr oldset = NULL;
 
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_LOCATIONSET) &&
     (ctxt->value->type != XPATH_NODESET)))
        XP_ERROR(XPATH_INVALID_TYPE)
 
    obj = valuePop(ctxt);
    if (obj->type == XPATH_NODESET) {
    /*
     * First convert to a location set
     */
    tmp = xmlXPtrNewLocationSetNodeSet(obj->nodesetval);
    xmlXPathFreeObject(obj);
    if (tmp == NULL)
            XP_ERROR(XPATH_MEMORY_ERROR)
    obj = tmp;
    }
 
    newset = xmlXPtrLocationSetCreate(NULL);
    if (newset == NULL) {
    xmlXPathFreeObject(obj);
        XP_ERROR(XPATH_MEMORY_ERROR);
    }
    oldset = (xmlLocationSetPtr) obj->user;
    if (oldset != NULL) {
    int i;
 
    for (i = 0; i < oldset->locNr; i++) {
        tmp = oldset->locTab[i];
        if (tmp == NULL)
        continue;
        point = NULL;
        switch (tmp->type) {
        case XPATH_POINT:
            point = xmlXPtrNewPoint(tmp->user, tmp->index);
            break;
        case XPATH_RANGE: {
            xmlNodePtr node = tmp->user;
            if (node != NULL) {
            if ((node->type == XML_ATTRIBUTE_NODE) ||
                            (node->type == XML_NAMESPACE_DECL)) {
                xmlXPathFreeObject(obj);
                xmlXPtrFreeLocationSet(newset);
                XP_ERROR(XPTR_SYNTAX_ERROR);
            }
            point = xmlXPtrNewPoint(node, tmp->index);
            }
            break;
            }
        default:
            /*** Should we raise an error ?
            xmlXPathFreeObject(obj);
            xmlXPathFreeObject(newset);
            XP_ERROR(XPATH_INVALID_TYPE)
            ***/
            break;
        }
            if (point != NULL)
        xmlXPtrLocationSetAdd(newset, point);
    }
    }
    xmlXPathFreeObject(obj);
    valuePush(ctxt, xmlXPtrWrapLocationSet(newset));
}
 
static void
xmlXPtrEndPointFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    xmlXPathObjectPtr tmp, obj, point;
    xmlLocationSetPtr newset = NULL;
    xmlLocationSetPtr oldset = NULL;
 
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_LOCATIONSET) &&
     (ctxt->value->type != XPATH_NODESET)))
        XP_ERROR(XPATH_INVALID_TYPE)
 
    obj = valuePop(ctxt);
    if (obj->type == XPATH_NODESET) {
    /*
     * First convert to a location set
     */
    tmp = xmlXPtrNewLocationSetNodeSet(obj->nodesetval);
    xmlXPathFreeObject(obj);
    if (tmp == NULL)
            XP_ERROR(XPATH_MEMORY_ERROR)
    obj = tmp;
    }
 
    newset = xmlXPtrLocationSetCreate(NULL);
    if (newset == NULL) {
    xmlXPathFreeObject(obj);
        XP_ERROR(XPATH_MEMORY_ERROR);
    }
    oldset = (xmlLocationSetPtr) obj->user;
    if (oldset != NULL) {
    int i;
 
    for (i = 0; i < oldset->locNr; i++) {
        tmp = oldset->locTab[i];
        if (tmp == NULL)
        continue;
        point = NULL;
        switch (tmp->type) {
        case XPATH_POINT:
            point = xmlXPtrNewPoint(tmp->user, tmp->index);
            break;
        case XPATH_RANGE: {
            xmlNodePtr node = tmp->user2;
            if (node != NULL) {
            if ((node->type == XML_ATTRIBUTE_NODE) ||
                            (node->type == XML_NAMESPACE_DECL)) {
                xmlXPathFreeObject(obj);
                xmlXPtrFreeLocationSet(newset);
                XP_ERROR(XPTR_SYNTAX_ERROR);
            }
            point = xmlXPtrNewPoint(node, tmp->index2);
            } else if (tmp->user == NULL) {
            point = xmlXPtrNewPoint(node,
                       xmlXPtrNbLocChildren(node));
            }
            break;
            }
        default:
            /*** Should we raise an error ?
            xmlXPathFreeObject(obj);
            xmlXPathFreeObject(newset);
            XP_ERROR(XPATH_INVALID_TYPE)
            ***/
            break;
        }
            if (point != NULL)
        xmlXPtrLocationSetAdd(newset, point);
    }
    }
    xmlXPathFreeObject(obj);
    valuePush(ctxt, xmlXPtrWrapLocationSet(newset));
}
 
 
static xmlXPathObjectPtr
xmlXPtrCoveringRange(xmlXPathParserContextPtr ctxt, xmlXPathObjectPtr loc) {
    if (loc == NULL)
    return(NULL);
    if ((ctxt == NULL) || (ctxt->context == NULL) ||
    (ctxt->context->doc == NULL))
    return(NULL);
    switch (loc->type) {
        case XPATH_POINT:
        return(xmlXPtrNewRange(loc->user, loc->index,
                       loc->user, loc->index));
        case XPATH_RANGE:
        if (loc->user2 != NULL) {
        return(xmlXPtrNewRange(loc->user, loc->index,
                          loc->user2, loc->index2));
        } else {
        xmlNodePtr node = (xmlNodePtr) loc->user;
        if (node == (xmlNodePtr) ctxt->context->doc) {
            return(xmlXPtrNewRange(node, 0, node,
                       xmlXPtrGetArity(node)));
        } else {
            switch (node->type) {
            case XML_ATTRIBUTE_NODE:
            /* !!! our model is slightly different than XPath */
                return(xmlXPtrNewRange(node, 0, node,
                               xmlXPtrGetArity(node)));
            case XML_ELEMENT_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
            case XML_DOCUMENT_NODE:
            case XML_NOTATION_NODE:
            case XML_HTML_DOCUMENT_NODE: {
                int indx = xmlXPtrGetIndex(node);
 
                node = node->parent;
                return(xmlXPtrNewRange(node, indx - 1,
                               node, indx + 1));
            }
            default:
                return(NULL);
            }
        }
        }
    default:
        TODO /* missed one case ??? */
    }
    return(NULL);
}
 
static void
xmlXPtrRangeFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    int i;
    xmlXPathObjectPtr set;
    xmlLocationSetPtr oldset;
    xmlLocationSetPtr newset;
 
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_LOCATIONSET) &&
     (ctxt->value->type != XPATH_NODESET)))
        XP_ERROR(XPATH_INVALID_TYPE)
 
    set = valuePop(ctxt);
    if (set->type == XPATH_NODESET) {
    xmlXPathObjectPtr tmp;
 
    /*
     * First convert to a location set
     */
    tmp = xmlXPtrNewLocationSetNodeSet(set->nodesetval);
    xmlXPathFreeObject(set);
    if (tmp == NULL)
            XP_ERROR(XPATH_MEMORY_ERROR)
    set = tmp;
    }
    oldset = (xmlLocationSetPtr) set->user;
 
    /*
     * The loop is to compute the covering range for each item and add it
     */
    newset = xmlXPtrLocationSetCreate(NULL);
    if (newset == NULL) {
    xmlXPathFreeObject(set);
        XP_ERROR(XPATH_MEMORY_ERROR);
    }
    if (oldset != NULL) {
        for (i = 0;i < oldset->locNr;i++) {
            xmlXPtrLocationSetAdd(newset,
                    xmlXPtrCoveringRange(ctxt, oldset->locTab[i]));
        }
    }
 
    /*
     * Save the new value and cleanup
     */
    valuePush(ctxt, xmlXPtrWrapLocationSet(newset));
    xmlXPathFreeObject(set);
}
 
static xmlXPathObjectPtr
xmlXPtrInsideRange(xmlXPathParserContextPtr ctxt, xmlXPathObjectPtr loc) {
    if (loc == NULL)
    return(NULL);
    if ((ctxt == NULL) || (ctxt->context == NULL) ||
    (ctxt->context->doc == NULL))
    return(NULL);
    switch (loc->type) {
        case XPATH_POINT: {
        xmlNodePtr node = (xmlNodePtr) loc->user;
        switch (node->type) {
        case XML_PI_NODE:
        case XML_COMMENT_NODE:
        case XML_TEXT_NODE:
        case XML_CDATA_SECTION_NODE: {
            if (node->content == NULL) {
            return(xmlXPtrNewRange(node, 0, node, 0));
            } else {
            return(xmlXPtrNewRange(node, 0, node,
                           xmlStrlen(node->content)));
            }
        }
        case XML_ATTRIBUTE_NODE:
        case XML_ELEMENT_NODE:
        case XML_ENTITY_REF_NODE:
        case XML_DOCUMENT_NODE:
        case XML_NOTATION_NODE:
        case XML_HTML_DOCUMENT_NODE: {
            return(xmlXPtrNewRange(node, 0, node,
                       xmlXPtrGetArity(node)));
        }
        default:
            break;
        }
        return(NULL);
    }
        case XPATH_RANGE: {
        xmlNodePtr node = (xmlNodePtr) loc->user;
        if (loc->user2 != NULL) {
        return(xmlXPtrNewRange(node, loc->index,
                           loc->user2, loc->index2));
        } else {
        switch (node->type) {
            case XML_PI_NODE:
            case XML_COMMENT_NODE:
            case XML_TEXT_NODE:
            case XML_CDATA_SECTION_NODE: {
            if (node->content == NULL) {
                return(xmlXPtrNewRange(node, 0, node, 0));
            } else {
                return(xmlXPtrNewRange(node, 0, node,
                           xmlStrlen(node->content)));
            }
            }
            case XML_ATTRIBUTE_NODE:
            case XML_ELEMENT_NODE:
            case XML_ENTITY_REF_NODE:
            case XML_DOCUMENT_NODE:
            case XML_NOTATION_NODE:
            case XML_HTML_DOCUMENT_NODE: {
            return(xmlXPtrNewRange(node, 0, node,
                           xmlXPtrGetArity(node)));
            }
            default:
            break;
        }
        return(NULL);
        }
        }
    default:
        TODO /* missed one case ??? */
    }
    return(NULL);
}
 
static void
xmlXPtrRangeInsideFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    int i;
    xmlXPathObjectPtr set;
    xmlLocationSetPtr oldset;
    xmlLocationSetPtr newset;
 
    CHECK_ARITY(1);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_LOCATIONSET) &&
     (ctxt->value->type != XPATH_NODESET)))
        XP_ERROR(XPATH_INVALID_TYPE)
 
    set = valuePop(ctxt);
    if (set->type == XPATH_NODESET) {
    xmlXPathObjectPtr tmp;
 
    /*
     * First convert to a location set
     */
    tmp = xmlXPtrNewLocationSetNodeSet(set->nodesetval);
    xmlXPathFreeObject(set);
    if (tmp == NULL)
         XP_ERROR(XPATH_MEMORY_ERROR)
    set = tmp;
    }
 
    /*
     * The loop is to compute the covering range for each item and add it
     */
    newset = xmlXPtrLocationSetCreate(NULL);
    if (newset == NULL) {
    xmlXPathFreeObject(set);
        XP_ERROR(XPATH_MEMORY_ERROR);
    }
    oldset = (xmlLocationSetPtr) set->user;
    if (oldset != NULL) {
        for (i = 0;i < oldset->locNr;i++) {
            xmlXPtrLocationSetAdd(newset,
                    xmlXPtrInsideRange(ctxt, oldset->locTab[i]));
        }
    }
 
    /*
     * Save the new value and cleanup
     */
    valuePush(ctxt, xmlXPtrWrapLocationSet(newset));
    xmlXPathFreeObject(set);
}
 
void
xmlXPtrRangeToFunction(xmlXPathParserContextPtr ctxt,
                       int nargs ATTRIBUTE_UNUSED) {
    XP_ERROR(XPATH_EXPR_ERROR);
}
 
xmlNodePtr
xmlXPtrAdvanceNode(xmlNodePtr cur, int *level) {
next:
    if ((cur == NULL) || (cur->type == XML_NAMESPACE_DECL))
    return(NULL);
    if (cur->children != NULL) {
        cur = cur->children ;
    if (level != NULL)
        (*level)++;
    goto found;
    }
skip:       /* This label should only be needed if something is wrong! */
    if (cur->next != NULL) {
    cur = cur->next;
    goto found;
    }
    do {
        cur = cur->parent;
    if (level != NULL)
        (*level)--;
        if (cur == NULL) return(NULL);
        if (cur->next != NULL) {
        cur = cur->next;
        goto found;
    }
    } while (cur != NULL);
 
found:
    if ((cur->type != XML_ELEMENT_NODE) &&
    (cur->type != XML_TEXT_NODE) &&
    (cur->type != XML_DOCUMENT_NODE) &&
    (cur->type != XML_HTML_DOCUMENT_NODE) &&
    (cur->type != XML_CDATA_SECTION_NODE)) {
        if (cur->type == XML_ENTITY_REF_NODE) { /* Shouldn't happen */
        TODO
        goto skip;
        }
        goto next;
    }
    return(cur);
}
 
static int
xmlXPtrAdvanceChar(xmlNodePtr *node, int *indx, int bytes) {
    xmlNodePtr cur;
    int pos;
    int len;
 
    if ((node == NULL) || (indx == NULL))
    return(-1);
    cur = *node;
    if ((cur == NULL) || (cur->type == XML_NAMESPACE_DECL))
    return(-1);
    pos = *indx;
 
    while (bytes >= 0) {
    /*
     * First position to the beginning of the first text node
     * corresponding to this point
     */
    while ((cur != NULL) &&
           ((cur->type == XML_ELEMENT_NODE) ||
            (cur->type == XML_DOCUMENT_NODE) ||
            (cur->type == XML_HTML_DOCUMENT_NODE))) {
        if (pos > 0) {
        cur = xmlXPtrGetNthChild(cur, pos);
        pos = 0;
        } else {
        cur = xmlXPtrAdvanceNode(cur, NULL);
        pos = 0;
        }
    }
 
    if (cur == NULL) {
        *node = NULL;
        *indx = 0;
        return(-1);
    }
 
    /*
     * if there is no move needed return the current value.
     */
    if (pos == 0) pos = 1;
    if (bytes == 0) {
        *node = cur;
        *indx = pos;
        return(0);
    }
    /*
     * We should have a text (or cdata) node ...
     */
    len = 0;
    if ((cur->type != XML_ELEMENT_NODE) &&
            (cur->content != NULL)) {
        len = xmlStrlen(cur->content);
    }
    if (pos > len) {
        /* Strange, the indx in the text node is greater than it's len */
        STRANGE
        pos = len;
    }
    if (pos + bytes >= len) {
        bytes -= (len - pos);
        cur = xmlXPtrAdvanceNode(cur, NULL);
        pos = 0;
    } else if (pos + bytes < len) {
        pos += bytes;
        *node = cur;
        *indx = pos;
        return(0);
    }
    }
    return(-1);
}
 
static int
xmlXPtrMatchString(const xmlChar *string, xmlNodePtr start, int startindex,
                xmlNodePtr *end, int *endindex) {
    xmlNodePtr cur;
    int pos; /* 0 based */
    int len; /* in bytes */
    int stringlen; /* in bytes */
    int match;
 
    if (string == NULL)
    return(-1);
    if ((start == NULL) || (start->type == XML_NAMESPACE_DECL))
    return(-1);
    if ((end == NULL) || (*end == NULL) ||
        ((*end)->type == XML_NAMESPACE_DECL) || (endindex == NULL))
    return(-1);
    cur = start;
    pos = startindex - 1;
    stringlen = xmlStrlen(string);
 
    while (stringlen > 0) {
    if ((cur == *end) && (pos + stringlen > *endindex))
        return(0);
 
    if ((cur->type != XML_ELEMENT_NODE) && (cur->content != NULL)) {
        len = xmlStrlen(cur->content);
        if (len >= pos + stringlen) {
        match = (!xmlStrncmp(&cur->content[pos], string, stringlen));
        if (match) {
#ifdef DEBUG_RANGES
            xmlGenericError(xmlGenericErrorContext,
                "found range %d bytes at index %d of ->",
                stringlen, pos + 1);
            xmlDebugDumpString(stdout, cur->content);
            xmlGenericError(xmlGenericErrorContext, "\n");
#endif
            *end = cur;
            *endindex = pos + stringlen;
            return(1);
        } else {
            return(0);
        }
        } else {
                int sub = len - pos;
        match = (!xmlStrncmp(&cur->content[pos], string, sub));
        if (match) {
#ifdef DEBUG_RANGES
            xmlGenericError(xmlGenericErrorContext,
                "found subrange %d bytes at index %d of ->",
                sub, pos + 1);
            xmlDebugDumpString(stdout, cur->content);
            xmlGenericError(xmlGenericErrorContext, "\n");
#endif
                    string = &string[sub];
            stringlen -= sub;
        } else {
            return(0);
        }
        }
    }
    cur = xmlXPtrAdvanceNode(cur, NULL);
    if (cur == NULL)
        return(0);
    pos = 0;
    }
    return(1);
}
 
static int
xmlXPtrSearchString(const xmlChar *string, xmlNodePtr *start, int *startindex,
                xmlNodePtr *end, int *endindex) {
    xmlNodePtr cur;
    const xmlChar *str;
    int pos; /* 0 based */
    int len; /* in bytes */
    xmlChar first;
 
    if (string == NULL)
    return(-1);
    if ((start == NULL) || (*start == NULL) ||
        ((*start)->type == XML_NAMESPACE_DECL) || (startindex == NULL))
    return(-1);
    if ((end == NULL) || (endindex == NULL))
    return(-1);
    cur = *start;
    pos = *startindex - 1;
    first = string[0];
 
    while (cur != NULL) {
    if ((cur->type != XML_ELEMENT_NODE) && (cur->content != NULL)) {
        len = xmlStrlen(cur->content);
        while (pos <= len) {
        if (first != 0) {
            str = xmlStrchr(&cur->content[pos], first);
            if (str != NULL) {
            pos = (str - (xmlChar *)(cur->content));
#ifdef DEBUG_RANGES
            xmlGenericError(xmlGenericErrorContext,
                "found '%c' at index %d of ->",
                first, pos + 1);
            xmlDebugDumpString(stdout, cur->content);
            xmlGenericError(xmlGenericErrorContext, "\n");
#endif
            if (xmlXPtrMatchString(string, cur, pos + 1,
                           end, endindex)) {
                *start = cur;
                *startindex = pos + 1;
                return(1);
            }
            pos++;
            } else {
            pos = len + 1;
            }
        } else {
            /*
             * An empty string is considered to match before each
             * character of the string-value and after the final
             * character.
             */
#ifdef DEBUG_RANGES
            xmlGenericError(xmlGenericErrorContext,
                "found '' at index %d of ->",
                pos + 1);
            xmlDebugDumpString(stdout, cur->content);
            xmlGenericError(xmlGenericErrorContext, "\n");
#endif
            *start = cur;
            *startindex = pos + 1;
            *end = cur;
            *endindex = pos + 1;
            return(1);
        }
        }
    }
    if ((cur == *end) && (pos >= *endindex))
        return(0);
    cur = xmlXPtrAdvanceNode(cur, NULL);
    if (cur == NULL)
        return(0);
    pos = 1;
    }
    return(0);
}
 
static int
xmlXPtrGetLastChar(xmlNodePtr *node, int *indx) {
    xmlNodePtr cur;
    int pos, len = 0;
 
    if ((node == NULL) || (*node == NULL) ||
        ((*node)->type == XML_NAMESPACE_DECL) || (indx == NULL))
    return(-1);
    cur = *node;
    pos = *indx;
 
    if ((cur->type == XML_ELEMENT_NODE) ||
    (cur->type == XML_DOCUMENT_NODE) ||
    (cur->type == XML_HTML_DOCUMENT_NODE)) {
    if (pos > 0) {
        cur = xmlXPtrGetNthChild(cur, pos);
    }
    }
    while (cur != NULL) {
    if (cur->last != NULL)
        cur = cur->last;
    else if ((cur->type != XML_ELEMENT_NODE) &&
             (cur->content != NULL)) {
        len = xmlStrlen(cur->content);
        break;
    } else {
        return(-1);
    }
    }
    if (cur == NULL)
    return(-1);
    *node = cur;
    *indx = len;
    return(0);
}
 
static int
xmlXPtrGetStartPoint(xmlXPathObjectPtr obj, xmlNodePtr *node, int *indx) {
    if ((obj == NULL) || (node == NULL) || (indx == NULL))
    return(-1);
 
    switch (obj->type) {
        case XPATH_POINT:
        *node = obj->user;
        if (obj->index <= 0)
        *indx = 0;
        else
        *indx = obj->index;
        return(0);
        case XPATH_RANGE:
        *node = obj->user;
        if (obj->index <= 0)
        *indx = 0;
        else
        *indx = obj->index;
        return(0);
    default:
        break;
    }
    return(-1);
}
 
static int
xmlXPtrGetEndPoint(xmlXPathObjectPtr obj, xmlNodePtr *node, int *indx) {
    if ((obj == NULL) || (node == NULL) || (indx == NULL))
    return(-1);
 
    switch (obj->type) {
        case XPATH_POINT:
        *node = obj->user;
        if (obj->index <= 0)
        *indx = 0;
        else
        *indx = obj->index;
        return(0);
        case XPATH_RANGE:
        *node = obj->user;
        if (obj->index <= 0)
        *indx = 0;
        else
        *indx = obj->index;
        return(0);
    default:
        break;
    }
    return(-1);
}
 
static void
xmlXPtrStringRangeFunction(xmlXPathParserContextPtr ctxt, int nargs) {
    int i, startindex, endindex = 0, fendindex;
    xmlNodePtr start, end = 0, fend;
    xmlXPathObjectPtr set = NULL;
    xmlLocationSetPtr oldset;
    xmlLocationSetPtr newset = NULL;
    xmlXPathObjectPtr string = NULL;
    xmlXPathObjectPtr position = NULL;
    xmlXPathObjectPtr number = NULL;
    int found, pos = 0, num = 0;
 
    /*
     * Grab the arguments
     */
    if ((nargs < 2) || (nargs > 4))
    XP_ERROR(XPATH_INVALID_ARITY);
 
    if (nargs >= 4) {
        if ((ctxt->value == NULL) || (ctxt->value->type != XPATH_NUMBER)) {
            xmlXPathErr(ctxt, XPATH_INVALID_TYPE);
            goto error;
        }
    number = valuePop(ctxt);
    if (number != NULL)
        num = (int) number->floatval;
    }
    if (nargs >= 3) {
        if ((ctxt->value == NULL) || (ctxt->value->type != XPATH_NUMBER)) {
            xmlXPathErr(ctxt, XPATH_INVALID_TYPE);
            goto error;
        }
    position = valuePop(ctxt);
    if (position != NULL)
        pos = (int) position->floatval;
    }
    if ((ctxt->value == NULL) || (ctxt->value->type != XPATH_STRING)) {
        xmlXPathErr(ctxt, XPATH_INVALID_TYPE);
        goto error;
    }
    string = valuePop(ctxt);
    if ((ctxt->value == NULL) ||
    ((ctxt->value->type != XPATH_LOCATIONSET) &&
     (ctxt->value->type != XPATH_NODESET))) {
        xmlXPathErr(ctxt, XPATH_INVALID_TYPE);
        goto error;
    }
    set = valuePop(ctxt);
    newset = xmlXPtrLocationSetCreate(NULL);
    if (newset == NULL) {
        xmlXPathErr(ctxt, XPATH_MEMORY_ERROR);
        goto error;
    }
    if (set->nodesetval == NULL) {
        goto error;
    }
    if (set->type == XPATH_NODESET) {
    xmlXPathObjectPtr tmp;
 
    /*
     * First convert to a location set
     */
    tmp = xmlXPtrNewLocationSetNodeSet(set->nodesetval);
    xmlXPathFreeObject(set);
        set = NULL;
    if (tmp == NULL) {
            xmlXPathErr(ctxt, XPATH_MEMORY_ERROR);
            goto error;
        }
    set = tmp;
    }
    oldset = (xmlLocationSetPtr) set->user;
 
    /*
     * The loop is to search for each element in the location set
     * the list of location set corresponding to that search
     */
    for (i = 0;i < oldset->locNr;i++) {
#ifdef DEBUG_RANGES
    xmlXPathDebugDumpObject(stdout, oldset->locTab[i], 0);
#endif
 
    xmlXPtrGetStartPoint(oldset->locTab[i], &start, &startindex);
    xmlXPtrGetEndPoint(oldset->locTab[i], &end, &endindex);
    xmlXPtrAdvanceChar(&start, &startindex, 0);
    xmlXPtrGetLastChar(&end, &endindex);
 
#ifdef DEBUG_RANGES
    xmlGenericError(xmlGenericErrorContext,
        "from index %d of ->", startindex);
    xmlDebugDumpString(stdout, start->content);
    xmlGenericError(xmlGenericErrorContext, "\n");
    xmlGenericError(xmlGenericErrorContext,
        "to index %d of ->", endindex);
    xmlDebugDumpString(stdout, end->content);
    xmlGenericError(xmlGenericErrorContext, "\n");
#endif
    do {
            fend = end;
            fendindex = endindex;
        found = xmlXPtrSearchString(string->stringval, &start, &startindex,
                                &fend, &fendindex);
        if (found == 1) {
        if (position == NULL) {
            xmlXPtrLocationSetAdd(newset,
             xmlXPtrNewRange(start, startindex, fend, fendindex));
        } else if (xmlXPtrAdvanceChar(&start, &startindex,
                                  pos - 1) == 0) {
            if ((number != NULL) && (num > 0)) {
            int rindx;
            xmlNodePtr rend;
            rend = start;
            rindx = startindex - 1;
            if (xmlXPtrAdvanceChar(&rend, &rindx,
                               num) == 0) {
                xmlXPtrLocationSetAdd(newset,
                    xmlXPtrNewRange(start, startindex,
                            rend, rindx));
            }
            } else if ((number != NULL) && (num <= 0)) {
            xmlXPtrLocationSetAdd(newset,
                    xmlXPtrNewRange(start, startindex,
                            start, startindex));
            } else {
            xmlXPtrLocationSetAdd(newset,
                    xmlXPtrNewRange(start, startindex,
                            fend, fendindex));
            }
        }
        start = fend;
        startindex = fendindex;
        if (string->stringval[0] == 0)
            startindex++;
        }
    } while (found == 1);
    }
 
    /*
     * Save the new value and cleanup
     */
error:
    if (newset != NULL)
        valuePush(ctxt, xmlXPtrWrapLocationSet(newset));
    xmlXPathFreeObject(set);
    xmlXPathFreeObject(string);
    if (position) xmlXPathFreeObject(position);
    if (number) xmlXPathFreeObject(number);
}
 
void
xmlXPtrEvalRangePredicate(xmlXPathParserContextPtr ctxt) {
    const xmlChar *cur;
    xmlXPathObjectPtr res;
    xmlXPathObjectPtr obj, tmp;
    xmlLocationSetPtr newset = NULL;
    xmlLocationSetPtr oldset;
    int i;
 
    if (ctxt == NULL) return;
 
    SKIP_BLANKS;
    if (CUR != '[') {
    XP_ERROR(XPATH_INVALID_PREDICATE_ERROR);
    }
    NEXT;
    SKIP_BLANKS;
 
    /*
     * Extract the old set, and then evaluate the result of the
     * expression for all the element in the set. use it to grow
     * up a new set.
     */
    CHECK_TYPE(XPATH_LOCATIONSET);
    obj = valuePop(ctxt);
    oldset = obj->user;
    ctxt->context->node = NULL;
 
    if ((oldset == NULL) || (oldset->locNr == 0)) {
    ctxt->context->contextSize = 0;
    ctxt->context->proximityPosition = 0;
    xmlXPathEvalExpr(ctxt);
    res = valuePop(ctxt);
    if (res != NULL)
        xmlXPathFreeObject(res);
    valuePush(ctxt, obj);
    CHECK_ERROR;
    } else {
    /*
     * Save the expression pointer since we will have to evaluate
     * it multiple times. Initialize the new set.
     */
        cur = ctxt->cur;
    newset = xmlXPtrLocationSetCreate(NULL);
 
        for (i = 0; i < oldset->locNr; i++) {
        ctxt->cur = cur;
 
        /*
         * Run the evaluation with a node list made of a single item
         * in the nodeset.
         */
        ctxt->context->node = oldset->locTab[i]->user;
        tmp = xmlXPathNewNodeSet(ctxt->context->node);
        valuePush(ctxt, tmp);
        ctxt->context->contextSize = oldset->locNr;
        ctxt->context->proximityPosition = i + 1;
 
        xmlXPathEvalExpr(ctxt);
        CHECK_ERROR;
 
        /*
         * The result of the evaluation need to be tested to
         * decided whether the filter succeeded or not
         */
        res = valuePop(ctxt);
        if (xmlXPathEvaluatePredicateResult(ctxt, res)) {
            xmlXPtrLocationSetAdd(newset,
            xmlXPathObjectCopy(oldset->locTab[i]));
        }
 
        /*
         * Cleanup
         */
        if (res != NULL)
        xmlXPathFreeObject(res);
        if (ctxt->value == tmp) {
        res = valuePop(ctxt);
        xmlXPathFreeObject(res);
        }
 
        ctxt->context->node = NULL;
    }
 
    /*
     * The result is used as the new evaluation set.
     */
    xmlXPathFreeObject(obj);
    ctxt->context->node = NULL;
    ctxt->context->contextSize = -1;
    ctxt->context->proximityPosition = -1;
    valuePush(ctxt, xmlXPtrWrapLocationSet(newset));
    }
    if (CUR != ']') {
    XP_ERROR(XPATH_INVALID_PREDICATE_ERROR);
    }
 
    NEXT;
    SKIP_BLANKS;
}
#endif /* LIBXML_XPTR_LOCS_ENABLED */
 
#endif