tif_dir.c

Go to the documentation of this file.

/* $Id: tif_dir.c,v 1.75.2.5 2010-06-09 21:15:27 bfriesen Exp $ */

/*
 * Copyright (c) 1988-1997 Sam Leffler
 * Copyright (c) 1991-1997 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and 
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 * 
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
 * 
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 */

/*
 * TIFF Library.
 *
 * Directory Tag Get & Set Routines.
 * (and also some miscellaneous stuff)
 */
#include "tiffiop.h"

/*
 * These are used in the backwards compatibility code...
 */
#define DATATYPE_VOID       0       /* !untyped data */
#define DATATYPE_INT        1       /* !signed integer data */
#define DATATYPE_UINT       2       /* !unsigned integer data */
#define DATATYPE_IEEEFP     3       /* !IEEE floating point data */

static void
setByteArray(void** vpp, void* vp, size_t nmemb, size_t elem_size)
{
    if (*vpp)
        _TIFFfree(*vpp), *vpp = 0;
    if (vp) {
        tsize_t bytes = nmemb * elem_size;
        if (elem_size && bytes / elem_size == nmemb)
            *vpp = (void*) _TIFFmalloc(bytes);
        if (*vpp)
            _TIFFmemcpy(*vpp, vp, bytes);
    }
}
void _TIFFsetByteArray(void** vpp, void* vp, uint32 n)
    { setByteArray(vpp, vp, n, 1); }
void _TIFFsetString(char** cpp, char* cp)
    { setByteArray((void**) cpp, (void*) cp, strlen(cp)+1, 1); }
void _TIFFsetNString(char** cpp, char* cp, uint32 n)
    { setByteArray((void**) cpp, (void*) cp, n, 1); }
void _TIFFsetShortArray(uint16** wpp, uint16* wp, uint32 n)
    { setByteArray((void**) wpp, (void*) wp, n, sizeof (uint16)); }
void _TIFFsetLongArray(uint32** lpp, uint32* lp, uint32 n)
    { setByteArray((void**) lpp, (void*) lp, n, sizeof (uint32)); }
void _TIFFsetFloatArray(float** fpp, float* fp, uint32 n)
    { setByteArray((void**) fpp, (void*) fp, n, sizeof (float)); }
void _TIFFsetDoubleArray(double** dpp, double* dp, uint32 n)
    { setByteArray((void**) dpp, (void*) dp, n, sizeof (double)); }

/*
 * Install extra samples information.
 */
static int
setExtraSamples(TIFFDirectory* td, va_list ap, uint32* v)
{
/* XXX: Unassociated alpha data == 999 is a known Corel Draw bug, see below */
#define EXTRASAMPLE_COREL_UNASSALPHA 999 

    uint16* va;
    uint32 i;

    *v = va_arg(ap, uint32);
    if ((uint16) *v > td->td_samplesperpixel)
        return 0;
    va = va_arg(ap, uint16*);
    if (*v > 0 && va == NULL)       /* typically missing param */
        return 0;
    for (i = 0; i < *v; i++) {
        if (va[i] > EXTRASAMPLE_UNASSALPHA) {
            /*
             * XXX: Corel Draw is known to produce incorrect
             * ExtraSamples tags which must be patched here if we
             * want to be able to open some of the damaged TIFF
             * files: 
             */
            if (va[i] == EXTRASAMPLE_COREL_UNASSALPHA)
                va[i] = EXTRASAMPLE_UNASSALPHA;
            else
                return 0;
        }
    }
    td->td_extrasamples = (uint16) *v;
    _TIFFsetShortArray(&td->td_sampleinfo, va, td->td_extrasamples);
    return 1;

#undef EXTRASAMPLE_COREL_UNASSALPHA
}

static uint32
checkInkNamesString(TIFF* tif, uint32 slen, const char* s)
{
    TIFFDirectory* td = &tif->tif_dir;
    uint16 i = td->td_samplesperpixel;

    if (slen > 0) {
        const char* ep = s+slen;
        const char* cp = s;
        for (; i > 0; i--) {
            for (; *cp != '\0'; cp++)
                if (cp >= ep)
                    goto bad;
            cp++;               /* skip \0 */
        }
        return (cp-s);
    }
bad:
    TIFFErrorExt(tif->tif_clientdata, "TIFFSetField",
        "%s: Invalid InkNames value; expecting %d names, found %d",
        tif->tif_name,
        td->td_samplesperpixel,
        td->td_samplesperpixel-i);
    return (0);
}

static int
_TIFFVSetField(TIFF* tif, ttag_t tag, va_list ap)
{
    static const char module[] = "_TIFFVSetField";

    TIFFDirectory* td = &tif->tif_dir;
    int status = 1;
    uint32 v32, i, v;
    char* s;

    switch (tag) {
    case TIFFTAG_SUBFILETYPE:
        td->td_subfiletype = va_arg(ap, uint32);
        break;
    case TIFFTAG_IMAGEWIDTH:
        td->td_imagewidth = va_arg(ap, uint32);
        break;
    case TIFFTAG_IMAGELENGTH:
        td->td_imagelength = va_arg(ap, uint32);
        break;
    case TIFFTAG_BITSPERSAMPLE:
        td->td_bitspersample = (uint16) va_arg(ap, int);
        /*
         * If the data require post-decoding processing to byte-swap
         * samples, set it up here.  Note that since tags are required
         * to be ordered, compression code can override this behaviour
         * in the setup method if it wants to roll the post decoding
         * work in with its normal work.
         */
        if (tif->tif_flags & TIFF_SWAB) {
            if (td->td_bitspersample == 16)
                tif->tif_postdecode = _TIFFSwab16BitData;
            else if (td->td_bitspersample == 24)
                tif->tif_postdecode = _TIFFSwab24BitData;
            else if (td->td_bitspersample == 32)
                tif->tif_postdecode = _TIFFSwab32BitData;
            else if (td->td_bitspersample == 64)
                tif->tif_postdecode = _TIFFSwab64BitData;
            else if (td->td_bitspersample == 128) /* two 64's */
                tif->tif_postdecode = _TIFFSwab64BitData;
        }
        break;
    case TIFFTAG_COMPRESSION:
        v = va_arg(ap, uint32) & 0xffff;
        /*
         * If we're changing the compression scheme, the notify the
         * previous module so that it can cleanup any state it's
         * setup.
         */
        if (TIFFFieldSet(tif, FIELD_COMPRESSION)) {
            if (td->td_compression == v)
                break;
            (*tif->tif_cleanup)(tif);
            tif->tif_flags &= ~TIFF_CODERSETUP;
        }
        /*
         * Setup new compression routine state.
         */
        if( (status = TIFFSetCompressionScheme(tif, v)) != 0 )
                    td->td_compression = (uint16) v;
                else
                    status = 0;
        break;
    case TIFFTAG_PHOTOMETRIC:
        td->td_photometric = (uint16) va_arg(ap, int);
        break;
    case TIFFTAG_THRESHHOLDING:
        td->td_threshholding = (uint16) va_arg(ap, int);
        break;
    case TIFFTAG_FILLORDER:
        v = va_arg(ap, uint32);
        if (v != FILLORDER_LSB2MSB && v != FILLORDER_MSB2LSB)
            goto badvalue;
        td->td_fillorder = (uint16) v;
        break;
    case TIFFTAG_ORIENTATION:
        v = va_arg(ap, uint32);
        if (v < ORIENTATION_TOPLEFT || ORIENTATION_LEFTBOT < v)
            goto badvalue;
        else
            td->td_orientation = (uint16) v;
        break;
    case TIFFTAG_SAMPLESPERPIXEL:
        /* XXX should cross check -- e.g. if pallette, then 1 */
        v = va_arg(ap, uint32);
        if (v == 0)
            goto badvalue;
        td->td_samplesperpixel = (uint16) v;
        break;
    case TIFFTAG_ROWSPERSTRIP:
        v32 = va_arg(ap, uint32);
        if (v32 == 0)
            goto badvalue32;
        td->td_rowsperstrip = v32;
        if (!TIFFFieldSet(tif, FIELD_TILEDIMENSIONS)) {
            td->td_tilelength = v32;
            td->td_tilewidth = td->td_imagewidth;
        }
        break;
    case TIFFTAG_MINSAMPLEVALUE:
        td->td_minsamplevalue = (uint16) va_arg(ap, int);
        break;
    case TIFFTAG_MAXSAMPLEVALUE:
        td->td_maxsamplevalue = (uint16) va_arg(ap, int);
        break;
    case TIFFTAG_SMINSAMPLEVALUE:
        td->td_sminsamplevalue = va_arg(ap, double);
        break;
    case TIFFTAG_SMAXSAMPLEVALUE:
        td->td_smaxsamplevalue = va_arg(ap, double);
        break;
    case TIFFTAG_XRESOLUTION:
        td->td_xresolution = (float) va_arg(ap, double);
        break;
    case TIFFTAG_YRESOLUTION:
        td->td_yresolution = (float) va_arg(ap, double);
        break;
    case TIFFTAG_PLANARCONFIG:
        v = va_arg(ap, uint32);
        if (v != PLANARCONFIG_CONTIG && v != PLANARCONFIG_SEPARATE)
            goto badvalue;
        td->td_planarconfig = (uint16) v;
        break;
    case TIFFTAG_XPOSITION:
        td->td_xposition = (float) va_arg(ap, double);
        break;
    case TIFFTAG_YPOSITION:
        td->td_yposition = (float) va_arg(ap, double);
        break;
    case TIFFTAG_RESOLUTIONUNIT:
        v = va_arg(ap, uint32);
        if (v < RESUNIT_NONE || RESUNIT_CENTIMETER < v)
            goto badvalue;
        td->td_resolutionunit = (uint16) v;
        break;
    case TIFFTAG_PAGENUMBER:
        td->td_pagenumber[0] = (uint16) va_arg(ap, int);
        td->td_pagenumber[1] = (uint16) va_arg(ap, int);
        break;
    case TIFFTAG_HALFTONEHINTS:
        td->td_halftonehints[0] = (uint16) va_arg(ap, int);
        td->td_halftonehints[1] = (uint16) va_arg(ap, int);
        break;
    case TIFFTAG_COLORMAP:
        v32 = (uint32)(1L<<td->td_bitspersample);
        _TIFFsetShortArray(&td->td_colormap[0], va_arg(ap, uint16*), v32);
        _TIFFsetShortArray(&td->td_colormap[1], va_arg(ap, uint16*), v32);
        _TIFFsetShortArray(&td->td_colormap[2], va_arg(ap, uint16*), v32);
        break;
    case TIFFTAG_EXTRASAMPLES:
        if (!setExtraSamples(td, ap, &v))
            goto badvalue;
        break;
    case TIFFTAG_MATTEING:
        td->td_extrasamples = (uint16) (va_arg(ap, int) != 0);
        if (td->td_extrasamples) {
            uint16 sv = EXTRASAMPLE_ASSOCALPHA;
            _TIFFsetShortArray(&td->td_sampleinfo, &sv, 1);
        }
        break;
    case TIFFTAG_TILEWIDTH:
        v32 = va_arg(ap, uint32);
        if (v32 % 16) {
            if (tif->tif_mode != O_RDONLY)
                goto badvalue32;
            TIFFWarningExt(tif->tif_clientdata, tif->tif_name,
                "Nonstandard tile width %d, convert file", v32);
        }
        td->td_tilewidth = v32;
        tif->tif_flags |= TIFF_ISTILED;
        break;
    case TIFFTAG_TILELENGTH:
        v32 = va_arg(ap, uint32);
        if (v32 % 16) {
            if (tif->tif_mode != O_RDONLY)
                goto badvalue32;
            TIFFWarningExt(tif->tif_clientdata, tif->tif_name,
                "Nonstandard tile length %d, convert file", v32);
        }
        td->td_tilelength = v32;
        tif->tif_flags |= TIFF_ISTILED;
        break;
    case TIFFTAG_TILEDEPTH:
        v32 = va_arg(ap, uint32);
        if (v32 == 0)
            goto badvalue32;
        td->td_tiledepth = v32;
        break;
    case TIFFTAG_DATATYPE:
        v = va_arg(ap, uint32);
        switch (v) {
        case DATATYPE_VOID: v = SAMPLEFORMAT_VOID;  break;
        case DATATYPE_INT:  v = SAMPLEFORMAT_INT;   break;
        case DATATYPE_UINT: v = SAMPLEFORMAT_UINT;  break;
        case DATATYPE_IEEEFP:   v = SAMPLEFORMAT_IEEEFP;break;
        default:        goto badvalue;
        }
        td->td_sampleformat = (uint16) v;
        break;
    case TIFFTAG_SAMPLEFORMAT:
        v = va_arg(ap, uint32);
        if (v < SAMPLEFORMAT_UINT || SAMPLEFORMAT_COMPLEXIEEEFP < v)
            goto badvalue;
        td->td_sampleformat = (uint16) v;

                /*  Try to fix up the SWAB function for complex data. */
                if( td->td_sampleformat == SAMPLEFORMAT_COMPLEXINT 
                    && td->td_bitspersample == 32
                    && tif->tif_postdecode == _TIFFSwab32BitData )
                    tif->tif_postdecode = _TIFFSwab16BitData;
                else if( (td->td_sampleformat == SAMPLEFORMAT_COMPLEXINT 
                          || td->td_sampleformat == SAMPLEFORMAT_COMPLEXIEEEFP)
                         && td->td_bitspersample == 64
                         && tif->tif_postdecode == _TIFFSwab64BitData )
                    tif->tif_postdecode = _TIFFSwab32BitData;
        break;
    case TIFFTAG_IMAGEDEPTH:
        td->td_imagedepth = va_arg(ap, uint32);
        break;
    case TIFFTAG_SUBIFD:
        if ((tif->tif_flags & TIFF_INSUBIFD) == 0) {
            td->td_nsubifd = (uint16) va_arg(ap, int);
            _TIFFsetLongArray(&td->td_subifd, va_arg(ap, uint32*),
                (long) td->td_nsubifd);
        } else {
            TIFFErrorExt(tif->tif_clientdata, module,
                     "%s: Sorry, cannot nest SubIFDs",
                     tif->tif_name);
            status = 0;
        }
        break;
    case TIFFTAG_YCBCRPOSITIONING:
        td->td_ycbcrpositioning = (uint16) va_arg(ap, int);
        break;
    case TIFFTAG_YCBCRSUBSAMPLING:
        td->td_ycbcrsubsampling[0] = (uint16) va_arg(ap, int);
        td->td_ycbcrsubsampling[1] = (uint16) va_arg(ap, int);
        break;
    case TIFFTAG_TRANSFERFUNCTION:
        v = (td->td_samplesperpixel - td->td_extrasamples) > 1 ? 3 : 1;
        for (i = 0; i < v; i++)
            _TIFFsetShortArray(&td->td_transferfunction[i],
                va_arg(ap, uint16*), 1L<<td->td_bitspersample);
        break;
    case TIFFTAG_REFERENCEBLACKWHITE:
        /* XXX should check for null range */
        _TIFFsetFloatArray(&td->td_refblackwhite, va_arg(ap, float*), 6);
        break;
    case TIFFTAG_INKNAMES:
        v = va_arg(ap, uint32);
        s = va_arg(ap, char*);
        v = checkInkNamesString(tif, v, s);
                status = v > 0;
        if( v > 0 ) {
            _TIFFsetNString(&td->td_inknames, s, v);
            td->td_inknameslen = v;
        }
        break;
        default: {
            TIFFTagValue *tv;
            int tv_size, iCustom;
        const TIFFFieldInfo* fip = _TIFFFindFieldInfo(tif, tag, TIFF_ANY);

            /*
         * This can happen if multiple images are open with different
         * codecs which have private tags.  The global tag information
         * table may then have tags that are valid for one file but not
         * the other. If the client tries to set a tag that is not valid
         * for the image's codec then we'll arrive here.  This
         * happens, for example, when tiffcp is used to convert between
         * compression schemes and codec-specific tags are blindly copied.
             */
            if(fip == NULL || fip->field_bit != FIELD_CUSTOM) {
        TIFFErrorExt(tif->tif_clientdata, module,
                 "%s: Invalid %stag \"%s\" (not supported by codec)",
                 tif->tif_name, isPseudoTag(tag) ? "pseudo-" : "",
                 fip ? fip->field_name : "Unknown");
        status = 0;
        break;
            }

            /*
             * Find the existing entry for this custom value.
             */
            tv = NULL;
            for (iCustom = 0; iCustom < td->td_customValueCount; iCustom++) {
            if (td->td_customValues[iCustom].info->field_tag == tag) {
                tv = td->td_customValues + iCustom;
                if (tv->value != NULL) {
                    _TIFFfree(tv->value);
                    tv->value = NULL;
                }
                break;
            }
            }

            /*
             * Grow the custom list if the entry was not found.
             */
            if(tv == NULL) {
        TIFFTagValue    *new_customValues;
        
        td->td_customValueCount++;
        new_customValues = (TIFFTagValue *)
            _TIFFrealloc(td->td_customValues,
                     sizeof(TIFFTagValue) * td->td_customValueCount);
        if (!new_customValues) {
            TIFFErrorExt(tif->tif_clientdata, module,
        "%s: Failed to allocate space for list of custom values",
                  tif->tif_name);
            status = 0;
            goto end;
        }

        td->td_customValues = new_customValues;

                tv = td->td_customValues + (td->td_customValueCount - 1);
                tv->info = fip;
                tv->value = NULL;
                tv->count = 0;
            }

            /*
             * Set custom value ... save a copy of the custom tag value.
             */
        tv_size = _TIFFDataSize(fip->field_type);
        if (tv_size == 0) {
            status = 0;
            TIFFErrorExt(tif->tif_clientdata, module,
                 "%s: Bad field type %d for \"%s\"",
                 tif->tif_name, fip->field_type,
                 fip->field_name);
            goto end;
        }
           
            if(fip->field_passcount) {
            if (fip->field_writecount == TIFF_VARIABLE2)
            tv->count = (uint32) va_arg(ap, uint32);
            else
            tv->count = (int) va_arg(ap, int);
        } else if (fip->field_writecount == TIFF_VARIABLE
               || fip->field_writecount == TIFF_VARIABLE2)
        tv->count = 1;
        else if (fip->field_writecount == TIFF_SPP)
        tv->count = td->td_samplesperpixel;
        else
                tv->count = fip->field_writecount;
            
    
        if (fip->field_type == TIFF_ASCII)
            _TIFFsetString((char **)&tv->value, va_arg(ap, char *));
        else {
        tv->value = _TIFFCheckMalloc(tif, tv_size, tv->count,
                         "Tag Value");
        if (!tv->value) {
            status = 0;
            goto end;
        }

        if ((fip->field_passcount
            || fip->field_writecount == TIFF_VARIABLE
            || fip->field_writecount == TIFF_VARIABLE2
            || fip->field_writecount == TIFF_SPP
            || tv->count > 1)
            && fip->field_tag != TIFFTAG_PAGENUMBER
            && fip->field_tag != TIFFTAG_HALFTONEHINTS
            && fip->field_tag != TIFFTAG_YCBCRSUBSAMPLING
            && fip->field_tag != TIFFTAG_DOTRANGE) {
                    _TIFFmemcpy(tv->value, va_arg(ap, void *),
                tv->count * tv_size);
        } else {
            /*
             * XXX: The following loop required to handle
             * TIFFTAG_PAGENUMBER, TIFFTAG_HALFTONEHINTS,
             * TIFFTAG_YCBCRSUBSAMPLING and TIFFTAG_DOTRANGE tags.
             * These tags are actually arrays and should be passed as
             * array pointers to TIFFSetField() function, but actually
             * passed as a list of separate values. This behaviour
             * must be changed in the future!
             */
            int i;
            char *val = (char *)tv->value;

            for (i = 0; i < tv->count; i++, val += tv_size) {
                switch (fip->field_type) {
                case TIFF_BYTE:
                case TIFF_UNDEFINED:
                    {
                    uint8 v = (uint8)va_arg(ap, int);
                    _TIFFmemcpy(val, &v, tv_size);
                    }
                    break;
                case TIFF_SBYTE:
                    {
                    int8 v = (int8)va_arg(ap, int);
                    _TIFFmemcpy(val, &v, tv_size);
                    }
                    break;
                case TIFF_SHORT:
                    {
                    uint16 v = (uint16)va_arg(ap, int);
                    _TIFFmemcpy(val, &v, tv_size);
                    }
                    break;
                case TIFF_SSHORT:
                    {
                    int16 v = (int16)va_arg(ap, int);
                    _TIFFmemcpy(val, &v, tv_size);
                    }
                    break;
                case TIFF_LONG:
                case TIFF_IFD:
                    {
                    uint32 v = va_arg(ap, uint32);
                    _TIFFmemcpy(val, &v, tv_size);
                    }
                    break;
                case TIFF_SLONG:
                    {
                    int32 v = va_arg(ap, int32);
                    _TIFFmemcpy(val, &v, tv_size);
                    }
                    break;
                case TIFF_RATIONAL:
                case TIFF_SRATIONAL:
                case TIFF_FLOAT:
                    {
                    float v = (float)va_arg(ap, double);
                    _TIFFmemcpy(val, &v, tv_size);
                    }
                    break;
                case TIFF_DOUBLE:
                    {
                    double v = va_arg(ap, double);
                    _TIFFmemcpy(val, &v, tv_size);
                    }
                    break;
                default:
                    _TIFFmemset(val, 0, tv_size);
                    status = 0;
                    break;
                }
            }
        }
        }
          }
    }
    if (status) {
        TIFFSetFieldBit(tif, _TIFFFieldWithTag(tif, tag)->field_bit);
        tif->tif_flags |= TIFF_DIRTYDIRECT;
    }

end:
    va_end(ap);
    return (status);
badvalue:
    TIFFErrorExt(tif->tif_clientdata, module,
             "%s: Bad value %d for \"%s\" tag",
             tif->tif_name, v,
             _TIFFFieldWithTag(tif, tag)->field_name);
    va_end(ap);
    return (0);
badvalue32:
    TIFFErrorExt(tif->tif_clientdata, module,
             "%s: Bad value %u for \"%s\" tag",
             tif->tif_name, v32,
             _TIFFFieldWithTag(tif, tag)->field_name);
    va_end(ap);
    return (0);
}

/*
 * Return 1/0 according to whether or not
 * it is permissible to set the tag's value.
 * Note that we allow ImageLength to be changed
 * so that we can append and extend to images.
 * Any other tag may not be altered once writing
 * has commenced, unless its value has no effect
 * on the format of the data that is written.
 */
static int
OkToChangeTag(TIFF* tif, ttag_t tag)
{
    const TIFFFieldInfo* fip = _TIFFFindFieldInfo(tif, tag, TIFF_ANY);
    if (!fip) {         /* unknown tag */
        TIFFErrorExt(tif->tif_clientdata, "TIFFSetField", "%s: Unknown %stag %u",
            tif->tif_name, isPseudoTag(tag) ? "pseudo-" : "", tag);
        return (0);
    }
    if (tag != TIFFTAG_IMAGELENGTH && (tif->tif_flags & TIFF_BEENWRITING) &&
        !fip->field_oktochange) {
        /*
         * Consult info table to see if tag can be changed
         * after we've started writing.  We only allow changes
         * to those tags that don't/shouldn't affect the
         * compression and/or format of the data.
         */
        TIFFErrorExt(tif->tif_clientdata, "TIFFSetField",
            "%s: Cannot modify tag \"%s\" while writing",
            tif->tif_name, fip->field_name);
        return (0);
    }
    return (1);
}

/*
 * Record the value of a field in the
 * internal directory structure.  The
 * field will be written to the file
 * when/if the directory structure is
 * updated.
 */
int
TIFFSetField(TIFF* tif, ttag_t tag, ...)
{
    va_list ap;
    int status;

    va_start(ap, tag);
    status = TIFFVSetField(tif, tag, ap);
    va_end(ap);
    return (status);
}

/*
 * Like TIFFSetField, but taking a varargs
 * parameter list.  This routine is useful
 * for building higher-level interfaces on
 * top of the library.
 */
int
TIFFVSetField(TIFF* tif, ttag_t tag, va_list ap)
{
    return OkToChangeTag(tif, tag) ?
        (*tif->tif_tagmethods.vsetfield)(tif, tag, ap) : 0;
}

static int
_TIFFVGetField(TIFF* tif, ttag_t tag, va_list ap)
{
    TIFFDirectory* td = &tif->tif_dir;
    int            ret_val = 1;

    switch (tag) {
    case TIFFTAG_SUBFILETYPE:
            *va_arg(ap, uint32*) = td->td_subfiletype;
            break;
    case TIFFTAG_IMAGEWIDTH:
            *va_arg(ap, uint32*) = td->td_imagewidth;
            break;
    case TIFFTAG_IMAGELENGTH:
            *va_arg(ap, uint32*) = td->td_imagelength;
            break;
    case TIFFTAG_BITSPERSAMPLE:
            *va_arg(ap, uint16*) = td->td_bitspersample;
            break;
    case TIFFTAG_COMPRESSION:
            *va_arg(ap, uint16*) = td->td_compression;
            break;
    case TIFFTAG_PHOTOMETRIC:
            *va_arg(ap, uint16*) = td->td_photometric;
            break;
    case TIFFTAG_THRESHHOLDING:
            *va_arg(ap, uint16*) = td->td_threshholding;
            break;
    case TIFFTAG_FILLORDER:
            *va_arg(ap, uint16*) = td->td_fillorder;
            break;
    case TIFFTAG_ORIENTATION:
            *va_arg(ap, uint16*) = td->td_orientation;
            break;
    case TIFFTAG_SAMPLESPERPIXEL:
            *va_arg(ap, uint16*) = td->td_samplesperpixel;
            break;
    case TIFFTAG_ROWSPERSTRIP:
            *va_arg(ap, uint32*) = td->td_rowsperstrip;
            break;
    case TIFFTAG_MINSAMPLEVALUE:
            *va_arg(ap, uint16*) = td->td_minsamplevalue;
            break;
    case TIFFTAG_MAXSAMPLEVALUE:
            *va_arg(ap, uint16*) = td->td_maxsamplevalue;
            break;
    case TIFFTAG_SMINSAMPLEVALUE:
            *va_arg(ap, double*) = td->td_sminsamplevalue;
            break;
    case TIFFTAG_SMAXSAMPLEVALUE:
            *va_arg(ap, double*) = td->td_smaxsamplevalue;
            break;
    case TIFFTAG_XRESOLUTION:
            *va_arg(ap, float*) = td->td_xresolution;
            break;
    case TIFFTAG_YRESOLUTION:
            *va_arg(ap, float*) = td->td_yresolution;
            break;
    case TIFFTAG_PLANARCONFIG:
            *va_arg(ap, uint16*) = td->td_planarconfig;
            break;
    case TIFFTAG_XPOSITION:
            *va_arg(ap, float*) = td->td_xposition;
            break;
    case TIFFTAG_YPOSITION:
            *va_arg(ap, float*) = td->td_yposition;
            break;
    case TIFFTAG_RESOLUTIONUNIT:
            *va_arg(ap, uint16*) = td->td_resolutionunit;
            break;
    case TIFFTAG_PAGENUMBER:
            *va_arg(ap, uint16*) = td->td_pagenumber[0];
            *va_arg(ap, uint16*) = td->td_pagenumber[1];
            break;
    case TIFFTAG_HALFTONEHINTS:
            *va_arg(ap, uint16*) = td->td_halftonehints[0];
            *va_arg(ap, uint16*) = td->td_halftonehints[1];
            break;
    case TIFFTAG_COLORMAP:
            *va_arg(ap, uint16**) = td->td_colormap[0];
            *va_arg(ap, uint16**) = td->td_colormap[1];
            *va_arg(ap, uint16**) = td->td_colormap[2];
            break;
    case TIFFTAG_STRIPOFFSETS:
    case TIFFTAG_TILEOFFSETS:
            *va_arg(ap, uint32**) = td->td_stripoffset;
            break;
    case TIFFTAG_STRIPBYTECOUNTS:
    case TIFFTAG_TILEBYTECOUNTS:
            *va_arg(ap, uint32**) = td->td_stripbytecount;
            break;
    case TIFFTAG_MATTEING:
            *va_arg(ap, uint16*) =
                (td->td_extrasamples == 1 &&
                 td->td_sampleinfo[0] == EXTRASAMPLE_ASSOCALPHA);
            break;
    case TIFFTAG_EXTRASAMPLES:
            *va_arg(ap, uint16*) = td->td_extrasamples;
            *va_arg(ap, uint16**) = td->td_sampleinfo;
            break;
    case TIFFTAG_TILEWIDTH:
            *va_arg(ap, uint32*) = td->td_tilewidth;
            break;
    case TIFFTAG_TILELENGTH:
            *va_arg(ap, uint32*) = td->td_tilelength;
            break;
    case TIFFTAG_TILEDEPTH:
            *va_arg(ap, uint32*) = td->td_tiledepth;
            break;
    case TIFFTAG_DATATYPE:
            switch (td->td_sampleformat) {
        case SAMPLEFORMAT_UINT:
                    *va_arg(ap, uint16*) = DATATYPE_UINT;
                    break;
        case SAMPLEFORMAT_INT:
                    *va_arg(ap, uint16*) = DATATYPE_INT;
                    break;
        case SAMPLEFORMAT_IEEEFP:
                    *va_arg(ap, uint16*) = DATATYPE_IEEEFP;
                    break;
        case SAMPLEFORMAT_VOID:
                    *va_arg(ap, uint16*) = DATATYPE_VOID;
                    break;
            }
            break;
    case TIFFTAG_SAMPLEFORMAT:
            *va_arg(ap, uint16*) = td->td_sampleformat;
            break;
    case TIFFTAG_IMAGEDEPTH:
            *va_arg(ap, uint32*) = td->td_imagedepth;
            break;
    case TIFFTAG_SUBIFD:
            *va_arg(ap, uint16*) = td->td_nsubifd;
            *va_arg(ap, uint32**) = td->td_subifd;
            break;
    case TIFFTAG_YCBCRPOSITIONING:
            *va_arg(ap, uint16*) = td->td_ycbcrpositioning;
            break;
    case TIFFTAG_YCBCRSUBSAMPLING:
            *va_arg(ap, uint16*) = td->td_ycbcrsubsampling[0];
            *va_arg(ap, uint16*) = td->td_ycbcrsubsampling[1];
            break;
    case TIFFTAG_TRANSFERFUNCTION:
            *va_arg(ap, uint16**) = td->td_transferfunction[0];
            if (td->td_samplesperpixel - td->td_extrasamples > 1) {
                *va_arg(ap, uint16**) = td->td_transferfunction[1];
                *va_arg(ap, uint16**) = td->td_transferfunction[2];
            }
            break;
    case TIFFTAG_REFERENCEBLACKWHITE:
        *va_arg(ap, float**) = td->td_refblackwhite;
        break;
    case TIFFTAG_INKNAMES:
            *va_arg(ap, char**) = td->td_inknames;
            break;
        default:
        {
            const TIFFFieldInfo* fip = _TIFFFindFieldInfo(tif, tag, TIFF_ANY);
            int           i;
            
            /*
         * This can happen if multiple images are open with different
         * codecs which have private tags.  The global tag information
         * table may then have tags that are valid for one file but not
         * the other. If the client tries to get a tag that is not valid
         * for the image's codec then we'll arrive here.
             */
            if( fip == NULL || fip->field_bit != FIELD_CUSTOM )
            {
            TIFFErrorExt(tif->tif_clientdata, "_TIFFVGetField",
                 "%s: Invalid %stag \"%s\" "
                 "(not supported by codec)",
                 tif->tif_name,
                 isPseudoTag(tag) ? "pseudo-" : "",
                 fip ? fip->field_name : "Unknown");
            ret_val = 0;
            break;
            }

            /*
         * Do we have a custom value?
         */
            ret_val = 0;
            for (i = 0; i < td->td_customValueCount; i++) {
        TIFFTagValue *tv = td->td_customValues + i;

        if (tv->info->field_tag != tag)
            continue;
                
        if (fip->field_passcount) {
            if (fip->field_readcount == TIFF_VARIABLE2) 
                *va_arg(ap, uint32*) = (uint32)tv->count;
            else    /* Assume TIFF_VARIABLE */
                *va_arg(ap, uint16*) = (uint16)tv->count;
            *va_arg(ap, void **) = tv->value;
            ret_val = 1;
                } else {
            if ((fip->field_type == TIFF_ASCII
                || fip->field_readcount == TIFF_VARIABLE
                || fip->field_readcount == TIFF_VARIABLE2
                || fip->field_readcount == TIFF_SPP
                || tv->count > 1)
                && fip->field_tag != TIFFTAG_PAGENUMBER
                && fip->field_tag != TIFFTAG_HALFTONEHINTS
                && fip->field_tag != TIFFTAG_YCBCRSUBSAMPLING
                && fip->field_tag != TIFFTAG_DOTRANGE) {
                *va_arg(ap, void **) = tv->value;
                ret_val = 1;
            } else {
                int j;
                char *val = (char *)tv->value;

                for (j = 0; j < tv->count;
                 j++, val += _TIFFDataSize(tv->info->field_type)) {
                switch (fip->field_type) {
                    case TIFF_BYTE:
                    case TIFF_UNDEFINED:
                        *va_arg(ap, uint8*) =
                            *(uint8 *)val;
                        ret_val = 1;
                        break;
                    case TIFF_SBYTE:
                        *va_arg(ap, int8*) =
                            *(int8 *)val;
                        ret_val = 1;
                        break;
                    case TIFF_SHORT:
                        *va_arg(ap, uint16*) =
                            *(uint16 *)val;
                        ret_val = 1;
                        break;
                    case TIFF_SSHORT:
                        *va_arg(ap, int16*) =
                            *(int16 *)val;
                        ret_val = 1;
                        break;
                    case TIFF_LONG:
                    case TIFF_IFD:
                        *va_arg(ap, uint32*) =
                            *(uint32 *)val;
                        ret_val = 1;
                        break;
                    case TIFF_SLONG:
                        *va_arg(ap, int32*) =
                            *(int32 *)val;
                        ret_val = 1;
                        break;
                    case TIFF_RATIONAL:
                    case TIFF_SRATIONAL:
                    case TIFF_FLOAT:
                        *va_arg(ap, float*) =
                            *(float *)val;
                        ret_val = 1;
                        break;
                    case TIFF_DOUBLE:
                        *va_arg(ap, double*) =
                            *(double *)val;
                        ret_val = 1;
                        break;
                    default:
                        ret_val = 0;
                        break;
                }
                }
            }
                }
        break;
            }
        }
    }
    return(ret_val);
}

/*
 * Return the value of a field in the
 * internal directory structure.
 */
int
TIFFGetField(TIFF* tif, ttag_t tag, ...)
{
    int status;
    va_list ap;

    va_start(ap, tag);
    status = TIFFVGetField(tif, tag, ap);
    va_end(ap);
    return (status);
}

/*
 * Like TIFFGetField, but taking a varargs
 * parameter list.  This routine is useful
 * for building higher-level interfaces on
 * top of the library.
 */
int
TIFFVGetField(TIFF* tif, ttag_t tag, va_list ap)
{
    const TIFFFieldInfo* fip = _TIFFFindFieldInfo(tif, tag, TIFF_ANY);
    return (fip && (isPseudoTag(tag) || TIFFFieldSet(tif, fip->field_bit)) ?
        (*tif->tif_tagmethods.vgetfield)(tif, tag, ap) : 0);
}

#define CleanupField(member) {      \
    if (td->member) {           \
    _TIFFfree(td->member);      \
    td->member = 0;         \
    }                   \
}

/*
 * Release storage associated with a directory.
 */
void
TIFFFreeDirectory(TIFF* tif)
{
    TIFFDirectory *td = &tif->tif_dir;
    int            i;

    _TIFFmemset(td->td_fieldsset, 0, FIELD_SETLONGS);
    CleanupField(td_colormap[0]);
    CleanupField(td_colormap[1]);
    CleanupField(td_colormap[2]);
    CleanupField(td_sampleinfo);
    CleanupField(td_subifd);
    CleanupField(td_inknames);
    CleanupField(td_refblackwhite);
    CleanupField(td_transferfunction[0]);
    CleanupField(td_transferfunction[1]);
    CleanupField(td_transferfunction[2]);
    CleanupField(td_stripoffset);
    CleanupField(td_stripbytecount);
    TIFFClrFieldBit(tif, FIELD_YCBCRSUBSAMPLING);
    TIFFClrFieldBit(tif, FIELD_YCBCRPOSITIONING);

    /* Cleanup custom tag values */
    for( i = 0; i < td->td_customValueCount; i++ ) {
        if (td->td_customValues[i].value)
            _TIFFfree(td->td_customValues[i].value);
    }

    td->td_customValueCount = 0;
    CleanupField(td_customValues);
}
#undef CleanupField

/*
 * Client Tag extension support (from Niles Ritter).
 */
static TIFFExtendProc _TIFFextender = (TIFFExtendProc) NULL;

TIFFExtendProc
TIFFSetTagExtender(TIFFExtendProc extender)
{
    TIFFExtendProc prev = _TIFFextender;
    _TIFFextender = extender;
    return (prev);
}

/*
 * Setup for a new directory.  Should we automatically call
 * TIFFWriteDirectory() if the current one is dirty?
 *
 * The newly created directory will not exist on the file till
 * TIFFWriteDirectory(), TIFFFlush() or TIFFClose() is called.
 */
int
TIFFCreateDirectory(TIFF* tif)
{
    TIFFDefaultDirectory(tif);
    tif->tif_diroff = 0;
    tif->tif_nextdiroff = 0;
    tif->tif_curoff = 0;
    tif->tif_row = (uint32) -1;
    tif->tif_curstrip = (tstrip_t) -1;

    return 0;
}

/*
 * Setup a default directory structure.
 */
int
TIFFDefaultDirectory(TIFF* tif)
{
    register TIFFDirectory* td = &tif->tif_dir;

    size_t tiffFieldInfoCount;
    const TIFFFieldInfo *tiffFieldInfo =
        _TIFFGetFieldInfo(&tiffFieldInfoCount);
    _TIFFSetupFieldInfo(tif, tiffFieldInfo, tiffFieldInfoCount);

    _TIFFmemset(td, 0, sizeof (*td));
    td->td_fillorder = FILLORDER_MSB2LSB;
    td->td_bitspersample = 1;
    td->td_threshholding = THRESHHOLD_BILEVEL;
    td->td_orientation = ORIENTATION_TOPLEFT;
    td->td_samplesperpixel = 1;
    td->td_rowsperstrip = (uint32) -1;
    td->td_tilewidth = 0;
    td->td_tilelength = 0;
    td->td_tiledepth = 1;
    td->td_stripbytecountsorted = 1; /* Our own arrays always sorted. */
    td->td_resolutionunit = RESUNIT_INCH;
    td->td_sampleformat = SAMPLEFORMAT_UINT;
    td->td_imagedepth = 1;
    td->td_ycbcrsubsampling[0] = 2;
    td->td_ycbcrsubsampling[1] = 2;
    td->td_ycbcrpositioning = YCBCRPOSITION_CENTERED;
    tif->tif_postdecode = _TIFFNoPostDecode;
    tif->tif_foundfield = NULL;
    tif->tif_tagmethods.vsetfield = _TIFFVSetField;
    tif->tif_tagmethods.vgetfield = _TIFFVGetField;
    tif->tif_tagmethods.printdir = NULL;
    /*
     *  Give client code a chance to install their own
     *  tag extensions & methods, prior to compression overloads.
     */
    if (_TIFFextender)
        (*_TIFFextender)(tif);
    (void) TIFFSetField(tif, TIFFTAG_COMPRESSION, COMPRESSION_NONE);
    /*
     * NB: The directory is marked dirty as a result of setting
     * up the default compression scheme.  However, this really
     * isn't correct -- we want TIFF_DIRTYDIRECT to be set only
     * if the user does something.  We could just do the setup
     * by hand, but it seems better to use the normal mechanism
     * (i.e. TIFFSetField).
     */
    tif->tif_flags &= ~TIFF_DIRTYDIRECT;

    /*
     * As per http://bugzilla.remotesensing.org/show_bug.cgi?id=19
     * we clear the ISTILED flag when setting up a new directory.
     * Should we also be clearing stuff like INSUBIFD?
     */
    tif->tif_flags &= ~TIFF_ISTILED;
        /*
         * Clear other directory-specific fields.
         */
        tif->tif_tilesize = -1;
        tif->tif_scanlinesize = -1;

    return (1);
}

static int
TIFFAdvanceDirectory(TIFF* tif, uint32* nextdir, toff_t* off)
{
    static const char module[] = "TIFFAdvanceDirectory";
    uint16 dircount;
    if (isMapped(tif))
    {
        toff_t poff=*nextdir;
        if (poff+sizeof(uint16) > tif->tif_size)
        {
            TIFFErrorExt(tif->tif_clientdata, module, "%s: Error fetching directory count",
                tif->tif_name);
            return (0);
        }
        _TIFFmemcpy(&dircount, tif->tif_base+poff, sizeof (uint16));
        if (tif->tif_flags & TIFF_SWAB)
            TIFFSwabShort(&dircount);
        poff+=sizeof (uint16)+dircount*sizeof (TIFFDirEntry);
        if (off != NULL)
            *off = poff;
        if (((toff_t) (poff+sizeof (uint32))) > tif->tif_size)
        {
            TIFFErrorExt(tif->tif_clientdata, module, "%s: Error fetching directory link",
                tif->tif_name);
            return (0);
        }
        _TIFFmemcpy(nextdir, tif->tif_base+poff, sizeof (uint32));
        if (tif->tif_flags & TIFF_SWAB)
            TIFFSwabLong(nextdir);
        return (1);
    }
    else
    {
        if (!SeekOK(tif, *nextdir) ||
            !ReadOK(tif, &dircount, sizeof (uint16))) {
            TIFFErrorExt(tif->tif_clientdata, module, "%s: Error fetching directory count",
                tif->tif_name);
            return (0);
        }
        if (tif->tif_flags & TIFF_SWAB)
            TIFFSwabShort(&dircount);
        if (off != NULL)
            *off = TIFFSeekFile(tif,
                dircount*sizeof (TIFFDirEntry), SEEK_CUR);
        else
            (void) TIFFSeekFile(tif,
                dircount*sizeof (TIFFDirEntry), SEEK_CUR);
        if (!ReadOK(tif, nextdir, sizeof (uint32))) {
            TIFFErrorExt(tif->tif_clientdata, module, "%s: Error fetching directory link",
                tif->tif_name);
            return (0);
        }
        if (tif->tif_flags & TIFF_SWAB)
            TIFFSwabLong(nextdir);
        return (1);
    }
}

/*
 * Count the number of directories in a file.
 */
tdir_t
TIFFNumberOfDirectories(TIFF* tif)
{
    toff_t nextdir = tif->tif_header.tiff_diroff;
    tdir_t n = 0;
    
    while (nextdir != 0 && TIFFAdvanceDirectory(tif, &nextdir, NULL))
        n++;
    return (n);
}

/*
 * Set the n-th directory as the current directory.
 * NB: Directories are numbered starting at 0.
 */
int
TIFFSetDirectory(TIFF* tif, tdir_t dirn)
{
    toff_t nextdir;
    tdir_t n;

    nextdir = tif->tif_header.tiff_diroff;
    for (n = dirn; n > 0 && nextdir != 0; n--)
        if (!TIFFAdvanceDirectory(tif, &nextdir, NULL))
            return (0);
    tif->tif_nextdiroff = nextdir;
    /*
     * Set curdir to the actual directory index.  The
     * -1 is because TIFFReadDirectory will increment
     * tif_curdir after successfully reading the directory.
     */
    tif->tif_curdir = (dirn - n) - 1;
    /*
     * Reset tif_dirnumber counter and start new list of seen directories.
     * We need this to prevent IFD loops.
     */
    tif->tif_dirnumber = 0;
    return (TIFFReadDirectory(tif));
}

/*
 * Set the current directory to be the directory
 * located at the specified file offset.  This interface
 * is used mainly to access directories linked with
 * the SubIFD tag (e.g. thumbnail images).
 */
int
TIFFSetSubDirectory(TIFF* tif, uint32 diroff)
{
    tif->tif_nextdiroff = diroff;
    /*
     * Reset tif_dirnumber counter and start new list of seen directories.
     * We need this to prevent IFD loops.
     */
    tif->tif_dirnumber = 0;
    return (TIFFReadDirectory(tif));
}

/*
 * Return file offset of the current directory.
 */
uint32
TIFFCurrentDirOffset(TIFF* tif)
{
    return (tif->tif_diroff);
}

/*
 * Return an indication of whether or not we are
 * at the last directory in the file.
 */
int
TIFFLastDirectory(TIFF* tif)
{
    return (tif->tif_nextdiroff == 0);
}

/*
 * Unlink the specified directory from the directory chain.
 */
int
TIFFUnlinkDirectory(TIFF* tif, tdir_t dirn)
{
    static const char module[] = "TIFFUnlinkDirectory";
    toff_t nextdir;
    toff_t off;
    tdir_t n;

    if (tif->tif_mode == O_RDONLY) {
        TIFFErrorExt(tif->tif_clientdata, module,
                             "Can not unlink directory in read-only file");
        return (0);
    }
    /*
     * Go to the directory before the one we want
     * to unlink and nab the offset of the link
     * field we'll need to patch.
     */
    nextdir = tif->tif_header.tiff_diroff;
    off = sizeof (uint16) + sizeof (uint16);
    for (n = dirn-1; n > 0; n--) {
        if (nextdir == 0) {
            TIFFErrorExt(tif->tif_clientdata, module, "Directory %d does not exist", dirn);
            return (0);
        }
        if (!TIFFAdvanceDirectory(tif, &nextdir, &off))
            return (0);
    }
    /*
     * Advance to the directory to be unlinked and fetch
     * the offset of the directory that follows.
     */
    if (!TIFFAdvanceDirectory(tif, &nextdir, NULL))
        return (0);
    /*
     * Go back and patch the link field of the preceding
     * directory to point to the offset of the directory
     * that follows.
     */
    (void) TIFFSeekFile(tif, off, SEEK_SET);
    if (tif->tif_flags & TIFF_SWAB)
        TIFFSwabLong(&nextdir);
    if (!WriteOK(tif, &nextdir, sizeof (uint32))) {
        TIFFErrorExt(tif->tif_clientdata, module, "Error writing directory link");
        return (0);
    }
    /*
     * Leave directory state setup safely.  We don't have
     * facilities for doing inserting and removing directories,
     * so it's safest to just invalidate everything.  This
     * means that the caller can only append to the directory
     * chain.
     */
    (*tif->tif_cleanup)(tif);
    if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata) {
        _TIFFfree(tif->tif_rawdata);
        tif->tif_rawdata = NULL;
        tif->tif_rawcc = 0;
    }
    tif->tif_flags &= ~(TIFF_BEENWRITING|TIFF_BUFFERSETUP|TIFF_POSTENCODE);
    TIFFFreeDirectory(tif);
    TIFFDefaultDirectory(tif);
    tif->tif_diroff = 0;            /* force link on next write */
    tif->tif_nextdiroff = 0;        /* next write must be at end */
    tif->tif_curoff = 0;
    tif->tif_row = (uint32) -1;
    tif->tif_curstrip = (tstrip_t) -1;
    return (1);
}

/*          [BFC]
 *
 * Author: Bruce Cameron <cameron@petris.com>
 *
 * Set a table of tags that are to be replaced during directory process by the
 * 'IGNORE' state - or return TRUE/FALSE for the requested tag such that
 * 'ReadDirectory' can use the stored information.
 *
 * FIXME: this is never used properly. Should be removed in the future.
 */
int
TIFFReassignTagToIgnore (enum TIFFIgnoreSense task, int TIFFtagID)
{
    static int TIFFignoretags [FIELD_LAST];
    static int tagcount = 0 ;
    int     i;                  /* Loop index */
    int     j;                  /* Loop index */

    switch (task)
    {
      case TIS_STORE:
        if ( tagcount < (FIELD_LAST - 1) )
        {
            for ( j = 0 ; j < tagcount ; ++j )
            {                   /* Do not add duplicate tag */
                if ( TIFFignoretags [j] == TIFFtagID )
                    return (TRUE) ;
            }
            TIFFignoretags [tagcount++] = TIFFtagID ;
            return (TRUE) ;
        }
        break ;
        
      case TIS_EXTRACT:
        for ( i = 0 ; i < tagcount ; ++i )
        {
            if ( TIFFignoretags [i] == TIFFtagID )
                return (TRUE) ;
        }
        break;
        
      case TIS_EMPTY:
        tagcount = 0 ;          /* Clear the list */
        return (TRUE) ;
        
      default:
        break;
    }
    
    return (FALSE);
}

/* vim: set ts=8 sts=8 sw=8 noet: */
/*
 * Local Variables:
 * mode: c
 * c-basic-offset: 8
 * fill-column: 78
 * End:
 */