tif_dirwrite.c

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/* $Id: tif_dirwrite.c,v 1.37.2.7 2010-06-08 18:50:42 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 Write Support Routines.
 */
#include "tiffiop.h"

#ifdef HAVE_IEEEFP
# define    TIFFCvtNativeToIEEEFloat(tif, n, fp)
# define    TIFFCvtNativeToIEEEDouble(tif, n, dp)
#else
extern  void TIFFCvtNativeToIEEEFloat(TIFF*, uint32, float*);
extern  void TIFFCvtNativeToIEEEDouble(TIFF*, uint32, double*);
#endif

static  int TIFFWriteNormalTag(TIFF*, TIFFDirEntry*, const TIFFFieldInfo*);
static  void TIFFSetupShortLong(TIFF*, ttag_t, TIFFDirEntry*, uint32);
static  void TIFFSetupShort(TIFF*, ttag_t, TIFFDirEntry*, uint16);
static  int TIFFSetupShortPair(TIFF*, ttag_t, TIFFDirEntry*);
static  int TIFFWritePerSampleShorts(TIFF*, ttag_t, TIFFDirEntry*);
static  int TIFFWritePerSampleAnys(TIFF*, TIFFDataType, ttag_t, TIFFDirEntry*);
static  int TIFFWriteShortTable(TIFF*, ttag_t, TIFFDirEntry*, uint32, uint16**);
static  int TIFFWriteShortArray(TIFF*, TIFFDirEntry*, uint16*);
static  int TIFFWriteLongArray(TIFF *, TIFFDirEntry*, uint32*);
static  int TIFFWriteRationalArray(TIFF *, TIFFDirEntry*, float*);
static  int TIFFWriteFloatArray(TIFF *, TIFFDirEntry*, float*);
static  int TIFFWriteDoubleArray(TIFF *, TIFFDirEntry*, double*);
static  int TIFFWriteByteArray(TIFF*, TIFFDirEntry*, char*);
static  int TIFFWriteAnyArray(TIFF*,
        TIFFDataType, ttag_t, TIFFDirEntry*, uint32, double*);
static  int TIFFWriteTransferFunction(TIFF*, TIFFDirEntry*);
static  int TIFFWriteInkNames(TIFF*, TIFFDirEntry*);
static  int TIFFWriteData(TIFF*, TIFFDirEntry*, char*);
static  int TIFFLinkDirectory(TIFF*);

#define WriteRationalPair(type, tag1, v1, tag2, v2) {       \
    TIFFWriteRational((tif), (type), (tag1), (dir), (v1))   \
    TIFFWriteRational((tif), (type), (tag2), (dir)+1, (v2)) \
    (dir)++;                        \
}
#define TIFFWriteRational(tif, type, tag, dir, v)       \
    (dir)->tdir_tag = (tag);                \
    (dir)->tdir_type = (type);              \
    (dir)->tdir_count = 1;                  \
    if (!TIFFWriteRationalArray((tif), (dir), &(v)))    \
        goto bad;

/*
 * Write the contents of the current directory
 * to the specified file.  This routine doesn't
 * handle overwriting a directory with auxiliary
 * storage that's been changed.
 */
static int
_TIFFWriteDirectory(TIFF* tif, int done)
{
    uint16 dircount;
    toff_t diroff;
    ttag_t tag;
    uint32 nfields;
    tsize_t dirsize;
    char* data;
    TIFFDirEntry* dir;
    TIFFDirectory* td;
    unsigned long b, fields[FIELD_SETLONGS];
    int fi, nfi;

    if (tif->tif_mode == O_RDONLY)
        return (1);
    /*
     * Clear write state so that subsequent images with
     * different characteristics get the right buffers
     * setup for them.
     */
    if (done)
    {
        if (tif->tif_flags & TIFF_POSTENCODE) {
            tif->tif_flags &= ~TIFF_POSTENCODE;
            if (!(*tif->tif_postencode)(tif)) {
                TIFFErrorExt(tif->tif_clientdata,
                         tif->tif_name,
                "Error post-encoding before directory write");
                return (0);
            }
        }
        (*tif->tif_close)(tif);     /* shutdown encoder */
        /*
         * Flush any data that might have been written
         * by the compression close+cleanup routines.
         */
        if (tif->tif_rawcc > 0
                    && (tif->tif_flags & TIFF_BEENWRITING) != 0
                    && !TIFFFlushData1(tif)) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                "Error flushing data before directory write");
            return (0);
        }
        if ((tif->tif_flags & TIFF_MYBUFFER) && tif->tif_rawdata) {
            _TIFFfree(tif->tif_rawdata);
            tif->tif_rawdata = NULL;
            tif->tif_rawcc = 0;
            tif->tif_rawdatasize = 0;
        }
        tif->tif_flags &= ~(TIFF_BEENWRITING|TIFF_BUFFERSETUP);
    }

    td = &tif->tif_dir;
    /*
     * Size the directory so that we can calculate
     * offsets for the data items that aren't kept
     * in-place in each field.
     */
    nfields = 0;
    for (b = 0; b <= FIELD_LAST; b++)
        if (TIFFFieldSet(tif, b) && b != FIELD_CUSTOM)
            nfields += (b < FIELD_SUBFILETYPE ? 2 : 1);
    nfields += td->td_customValueCount;
    dirsize = nfields * sizeof (TIFFDirEntry);
    data = (char*) _TIFFmalloc(dirsize);
    if (data == NULL) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                 "Cannot write directory, out of space");
        return (0);
    }
    /*
     * Directory hasn't been placed yet, put
     * it at the end of the file and link it
     * into the existing directory structure.
     */
    if (tif->tif_diroff == 0 && !TIFFLinkDirectory(tif))
        goto bad;
    tif->tif_dataoff = (toff_t)(
        tif->tif_diroff + sizeof (uint16) + dirsize + sizeof (toff_t));
    if (tif->tif_dataoff & 1)
        tif->tif_dataoff++;
    (void) TIFFSeekFile(tif, tif->tif_dataoff, SEEK_SET);
    tif->tif_curdir++;
    dir = (TIFFDirEntry*) data;
    /*
     * Setup external form of directory
     * entries and write data items.
     */
    _TIFFmemcpy(fields, td->td_fieldsset, sizeof (fields));
    /*
     * Write out ExtraSamples tag only if
     * extra samples are present in the data.
     */
    if (FieldSet(fields, FIELD_EXTRASAMPLES) && !td->td_extrasamples) {
        ResetFieldBit(fields, FIELD_EXTRASAMPLES);
        nfields--;
        dirsize -= sizeof (TIFFDirEntry);
    }                               /*XXX*/
    for (fi = 0, nfi = tif->tif_nfields; nfi > 0; nfi--, fi++) {
        const TIFFFieldInfo* fip = tif->tif_fieldinfo[fi];

        /*
         * For custom fields, we test to see if the custom field
         * is set or not.  For normal fields, we just use the
         * FieldSet test.
        */
        if( fip->field_bit == FIELD_CUSTOM )
        {
            int ci, is_set = FALSE;

            for( ci = 0; ci < td->td_customValueCount; ci++ )
                is_set |= (td->td_customValues[ci].info == fip);

            if( !is_set )
                continue;
        }
        else if (!FieldSet(fields, fip->field_bit))
            continue;

        /*
         * Handle other fields.
         */
        switch (fip->field_bit)
        {
        case FIELD_STRIPOFFSETS:
            /*
             * We use one field bit for both strip and tile

             * offsets, and so must be careful in selecting
             * the appropriate field descriptor (so that tags
             * are written in sorted order).
             */
            tag = isTiled(tif) ?
                TIFFTAG_TILEOFFSETS : TIFFTAG_STRIPOFFSETS;
            if (tag != fip->field_tag)
                continue;
            
            dir->tdir_tag = (uint16) tag;
            dir->tdir_type = (uint16) TIFF_LONG;
            dir->tdir_count = (uint32) td->td_nstrips;
            if (!TIFFWriteLongArray(tif, dir, td->td_stripoffset))
                goto bad;
            break;
        case FIELD_STRIPBYTECOUNTS:
            /*
             * We use one field bit for both strip and tile
             * byte counts, and so must be careful in selecting
             * the appropriate field descriptor (so that tags
             * are written in sorted order).
             */
            tag = isTiled(tif) ?
                TIFFTAG_TILEBYTECOUNTS : TIFFTAG_STRIPBYTECOUNTS;
            if (tag != fip->field_tag)
                continue;
            
            dir->tdir_tag = (uint16) tag;
            dir->tdir_type = (uint16) TIFF_LONG;
            dir->tdir_count = (uint32) td->td_nstrips;
            if (!TIFFWriteLongArray(tif, dir, td->td_stripbytecount))
                goto bad;
            break;
        case FIELD_ROWSPERSTRIP:
            TIFFSetupShortLong(tif, TIFFTAG_ROWSPERSTRIP,
                dir, td->td_rowsperstrip);
            break;
        case FIELD_COLORMAP:
            if (!TIFFWriteShortTable(tif, TIFFTAG_COLORMAP, dir,
                3, td->td_colormap))
                goto bad;
            break;
        case FIELD_IMAGEDIMENSIONS:
            TIFFSetupShortLong(tif, TIFFTAG_IMAGEWIDTH,
                dir++, td->td_imagewidth);
            TIFFSetupShortLong(tif, TIFFTAG_IMAGELENGTH,
                dir, td->td_imagelength);
            break;
        case FIELD_TILEDIMENSIONS:
            TIFFSetupShortLong(tif, TIFFTAG_TILEWIDTH,
                dir++, td->td_tilewidth);
            TIFFSetupShortLong(tif, TIFFTAG_TILELENGTH,
                dir, td->td_tilelength);
            break;
        case FIELD_COMPRESSION:
            TIFFSetupShort(tif, TIFFTAG_COMPRESSION,
                dir, td->td_compression);
            break;
        case FIELD_PHOTOMETRIC:
            TIFFSetupShort(tif, TIFFTAG_PHOTOMETRIC,
                dir, td->td_photometric);
            break;
        case FIELD_POSITION:
            WriteRationalPair(TIFF_RATIONAL,
                TIFFTAG_XPOSITION, td->td_xposition,
                TIFFTAG_YPOSITION, td->td_yposition);
            break;
        case FIELD_RESOLUTION:
            WriteRationalPair(TIFF_RATIONAL,
                TIFFTAG_XRESOLUTION, td->td_xresolution,
                TIFFTAG_YRESOLUTION, td->td_yresolution);
            break;
        case FIELD_BITSPERSAMPLE:
        case FIELD_MINSAMPLEVALUE:
        case FIELD_MAXSAMPLEVALUE:
        case FIELD_SAMPLEFORMAT:
            if (!TIFFWritePerSampleShorts(tif, fip->field_tag, dir))
                goto bad;
            break;
        case FIELD_SMINSAMPLEVALUE:
        case FIELD_SMAXSAMPLEVALUE:
            if (!TIFFWritePerSampleAnys(tif,
                _TIFFSampleToTagType(tif), fip->field_tag, dir))
                goto bad;
            break;
        case FIELD_PAGENUMBER:
        case FIELD_HALFTONEHINTS:
        case FIELD_YCBCRSUBSAMPLING:
            if (!TIFFSetupShortPair(tif, fip->field_tag, dir))
                goto bad;
            break;
        case FIELD_INKNAMES:
            if (!TIFFWriteInkNames(tif, dir))
                goto bad;
            break;
        case FIELD_TRANSFERFUNCTION:
            if (!TIFFWriteTransferFunction(tif, dir))
                goto bad;
            break;
        case FIELD_SUBIFD:
            /*
             * XXX: Always write this field using LONG type
             * for backward compatibility.
             */
            dir->tdir_tag = (uint16) fip->field_tag;
            dir->tdir_type = (uint16) TIFF_LONG;
            dir->tdir_count = (uint32) td->td_nsubifd;
            if (!TIFFWriteLongArray(tif, dir, td->td_subifd))
                goto bad;
            /*
             * Total hack: if this directory includes a SubIFD
             * tag then force the next <n> directories to be
             * written as ``sub directories'' of this one.  This
             * is used to write things like thumbnails and
             * image masks that one wants to keep out of the
             * normal directory linkage access mechanism.
             */
            if (dir->tdir_count > 0) {
                tif->tif_flags |= TIFF_INSUBIFD;
                tif->tif_nsubifd = (uint16) dir->tdir_count;
                if (dir->tdir_count > 1)
                    tif->tif_subifdoff = dir->tdir_offset;
                else
                    tif->tif_subifdoff = (uint32)(
                          tif->tif_diroff
                        + sizeof (uint16)
                        + ((char*)&dir->tdir_offset-data));
            }
            break;
        default:
            /* XXX: Should be fixed and removed. */
            if (fip->field_tag == TIFFTAG_DOTRANGE) {
                if (!TIFFSetupShortPair(tif, fip->field_tag, dir))
                    goto bad;
            }
            else if (!TIFFWriteNormalTag(tif, dir, fip))
                goto bad;
            break;
        }
        dir++;
                
        if( fip->field_bit != FIELD_CUSTOM )
            ResetFieldBit(fields, fip->field_bit);
    }

    /*
     * Write directory.
     */
    dircount = (uint16) nfields;
    diroff = (uint32) tif->tif_nextdiroff;
    if (tif->tif_flags & TIFF_SWAB) {
        /*
         * The file's byte order is opposite to the
         * native machine architecture.  We overwrite
         * the directory information with impunity
         * because it'll be released below after we
         * write it to the file.  Note that all the
         * other tag construction routines assume that
         * we do this byte-swapping; i.e. they only
         * byte-swap indirect data.
         */
        for (dir = (TIFFDirEntry*) data; dircount; dir++, dircount--) {
            TIFFSwabArrayOfShort(&dir->tdir_tag, 2);
            TIFFSwabArrayOfLong(&dir->tdir_count, 2);
        }
        dircount = (uint16) nfields;
        TIFFSwabShort(&dircount);
        TIFFSwabLong(&diroff);
    }
    (void) TIFFSeekFile(tif, tif->tif_diroff, SEEK_SET);
    if (!WriteOK(tif, &dircount, sizeof (dircount))) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                 "Error writing directory count");
        goto bad;
    }
    if (!WriteOK(tif, data, dirsize)) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                 "Error writing directory contents");
        goto bad;
    }
    if (!WriteOK(tif, &diroff, sizeof (uint32))) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                 "Error writing directory link");
        goto bad;
    }
    if (done) {
        TIFFFreeDirectory(tif);
        tif->tif_flags &= ~TIFF_DIRTYDIRECT;
        (*tif->tif_cleanup)(tif);

        /*
        * Reset directory-related state for subsequent
        * directories.
        */
        TIFFCreateDirectory(tif);
    }
    _TIFFfree(data);
    return (1);
bad:
    _TIFFfree(data);
    return (0);
}
#undef WriteRationalPair

int
TIFFWriteDirectory(TIFF* tif)
{
    return _TIFFWriteDirectory(tif, TRUE);
}

/*
 * Similar to TIFFWriteDirectory(), writes the directory out
 * but leaves all data structures in memory so that it can be
 * written again.  This will make a partially written TIFF file
 * readable before it is successfully completed/closed.
 */ 
int
TIFFCheckpointDirectory(TIFF* tif)
{
    int rc;
    /* Setup the strips arrays, if they haven't already been. */
    if (tif->tif_dir.td_stripoffset == NULL)
        (void) TIFFSetupStrips(tif);
    rc = _TIFFWriteDirectory(tif, FALSE);
    (void) TIFFSetWriteOffset(tif, TIFFSeekFile(tif, 0, SEEK_END));
    return rc;
}

static int
_TIFFWriteCustomDirectory(TIFF* tif, toff_t *pdiroff)
{
    uint16 dircount;
    uint32 nfields;
    tsize_t dirsize;
    char* data;
    TIFFDirEntry* dir;
    TIFFDirectory* td;
    unsigned long b, fields[FIELD_SETLONGS];
    int fi, nfi;

    if (tif->tif_mode == O_RDONLY)
        return (1);

    td = &tif->tif_dir;
    /*
     * Size the directory so that we can calculate
     * offsets for the data items that aren't kept
     * in-place in each field.
     */
    nfields = 0;
    for (b = 0; b <= FIELD_LAST; b++)
        if (TIFFFieldSet(tif, b) && b != FIELD_CUSTOM)
            nfields += (b < FIELD_SUBFILETYPE ? 2 : 1);
    nfields += td->td_customValueCount;
    dirsize = nfields * sizeof (TIFFDirEntry);
    data = (char*) _TIFFmalloc(dirsize);
    if (data == NULL) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                 "Cannot write directory, out of space");
        return (0);
    }
    /*
     * Put the directory  at the end of the file.
     */
    tif->tif_diroff = (TIFFSeekFile(tif, (toff_t) 0, SEEK_END)+1) &~ 1;
    tif->tif_dataoff = (toff_t)(
        tif->tif_diroff + sizeof (uint16) + dirsize + sizeof (toff_t));
    if (tif->tif_dataoff & 1)
        tif->tif_dataoff++;
    (void) TIFFSeekFile(tif, tif->tif_dataoff, SEEK_SET);
    dir = (TIFFDirEntry*) data;
    /*
     * Setup external form of directory
     * entries and write data items.
     */
    _TIFFmemcpy(fields, td->td_fieldsset, sizeof (fields));

    for (fi = 0, nfi = tif->tif_nfields; nfi > 0; nfi--, fi++) {
        const TIFFFieldInfo* fip = tif->tif_fieldinfo[fi];

        /*
         * For custom fields, we test to see if the custom field
         * is set or not.  For normal fields, we just use the
         * FieldSet test.
        */
        if( fip->field_bit == FIELD_CUSTOM )
        {
            int ci, is_set = FALSE;

            for( ci = 0; ci < td->td_customValueCount; ci++ )
                is_set |= (td->td_customValues[ci].info == fip);

            if( !is_set )
                continue;
        }
        else if (!FieldSet(fields, fip->field_bit))
            continue;
                
        if( fip->field_bit != FIELD_CUSTOM )
            ResetFieldBit(fields, fip->field_bit);
    }

    /*
     * Write directory.
     */
    dircount = (uint16) nfields;
    *pdiroff = (uint32) tif->tif_nextdiroff;
    if (tif->tif_flags & TIFF_SWAB) {
        /*
         * The file's byte order is opposite to the
         * native machine architecture.  We overwrite
         * the directory information with impunity
         * because it'll be released below after we
         * write it to the file.  Note that all the
         * other tag construction routines assume that
         * we do this byte-swapping; i.e. they only
         * byte-swap indirect data.
         */
        for (dir = (TIFFDirEntry*) data; dircount; dir++, dircount--) {
            TIFFSwabArrayOfShort(&dir->tdir_tag, 2);
            TIFFSwabArrayOfLong(&dir->tdir_count, 2);
        }
        dircount = (uint16) nfields;
        TIFFSwabShort(&dircount);
        TIFFSwabLong(pdiroff);
    }
    (void) TIFFSeekFile(tif, tif->tif_diroff, SEEK_SET);
    if (!WriteOK(tif, &dircount, sizeof (dircount))) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                 "Error writing directory count");
        goto bad;
    }
    if (!WriteOK(tif, data, dirsize)) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                 "Error writing directory contents");
        goto bad;
    }
    if (!WriteOK(tif, pdiroff, sizeof (uint32))) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                 "Error writing directory link");
        goto bad;
    }
    _TIFFfree(data);
    return (1);
bad:
    _TIFFfree(data);
    return (0);
}

int
TIFFWriteCustomDirectory(TIFF* tif, toff_t *pdiroff)
{
    return _TIFFWriteCustomDirectory(tif, pdiroff);
}

/*
 * Process tags that are not special cased.
 */
static int
TIFFWriteNormalTag(TIFF* tif, TIFFDirEntry* dir, const TIFFFieldInfo* fip)
{
    uint16 wc = (uint16) fip->field_writecount;
    uint32 wc2;

    dir->tdir_tag = (uint16) fip->field_tag;
    dir->tdir_type = (uint16) fip->field_type;
    dir->tdir_count = wc;
    
    switch (fip->field_type) {
    case TIFF_SHORT:
    case TIFF_SSHORT:
        if (fip->field_passcount) {
            uint16* wp;
            if (wc == (uint16) TIFF_VARIABLE2) {
                TIFFGetField(tif, fip->field_tag, &wc2, &wp);
                dir->tdir_count = wc2;
            } else {    /* Assume TIFF_VARIABLE */
                TIFFGetField(tif, fip->field_tag, &wc, &wp);
                dir->tdir_count = wc;
            }
            if (!TIFFWriteShortArray(tif, dir, wp))
                return 0;
        } else {
            if (wc == 1) {
                uint16 sv;
                TIFFGetField(tif, fip->field_tag, &sv);
                dir->tdir_offset =
                    TIFFInsertData(tif, dir->tdir_type, sv);
            } else {
                uint16* wp;
                TIFFGetField(tif, fip->field_tag, &wp);
                if (!TIFFWriteShortArray(tif, dir, wp))
                    return 0;
            }
        }
        break;
    case TIFF_LONG:
    case TIFF_SLONG:
    case TIFF_IFD:
        if (fip->field_passcount) {
            uint32* lp;
            if (wc == (uint16) TIFF_VARIABLE2) {
                TIFFGetField(tif, fip->field_tag, &wc2, &lp);
                dir->tdir_count = wc2;
            } else {    /* Assume TIFF_VARIABLE */
                TIFFGetField(tif, fip->field_tag, &wc, &lp);
                dir->tdir_count = wc;
            }
            if (!TIFFWriteLongArray(tif, dir, lp))
                return 0;
        } else {
            if (wc == 1) {
                /* XXX handle LONG->SHORT conversion */
                TIFFGetField(tif, fip->field_tag,
                         &dir->tdir_offset);
            } else {
                uint32* lp;
                TIFFGetField(tif, fip->field_tag, &lp);
                if (!TIFFWriteLongArray(tif, dir, lp))
                    return 0;
            }
        }
        break;
    case TIFF_RATIONAL:
    case TIFF_SRATIONAL:
        if (fip->field_passcount) {
            float* fp;
            if (wc == (uint16) TIFF_VARIABLE2) {
                TIFFGetField(tif, fip->field_tag, &wc2, &fp);
                dir->tdir_count = wc2;
            } else {    /* Assume TIFF_VARIABLE */
                TIFFGetField(tif, fip->field_tag, &wc, &fp);
                dir->tdir_count = wc;
            }
            if (!TIFFWriteRationalArray(tif, dir, fp))
                return 0;
        } else {
            if (wc == 1) {
                float fv;
                TIFFGetField(tif, fip->field_tag, &fv);
                if (!TIFFWriteRationalArray(tif, dir, &fv))
                    return 0;
            } else {
                float* fp;
                TIFFGetField(tif, fip->field_tag, &fp);
                if (!TIFFWriteRationalArray(tif, dir, fp))
                    return 0;
            }
        }
        break;
    case TIFF_FLOAT:
        if (fip->field_passcount) {
            float* fp;
            if (wc == (uint16) TIFF_VARIABLE2) {
                TIFFGetField(tif, fip->field_tag, &wc2, &fp);
                dir->tdir_count = wc2;
            } else {    /* Assume TIFF_VARIABLE */
                TIFFGetField(tif, fip->field_tag, &wc, &fp);
                dir->tdir_count = wc;
            }
            if (!TIFFWriteFloatArray(tif, dir, fp))
                return 0;
        } else {
            if (wc == 1) {
                float fv;
                TIFFGetField(tif, fip->field_tag, &fv);
                if (!TIFFWriteFloatArray(tif, dir, &fv))
                    return 0;
            } else {
                float* fp;
                TIFFGetField(tif, fip->field_tag, &fp);
                if (!TIFFWriteFloatArray(tif, dir, fp))
                    return 0;
            }
        }
        break;
    case TIFF_DOUBLE:
        if (fip->field_passcount) {
            double* dp;
            if (wc == (uint16) TIFF_VARIABLE2) {
                TIFFGetField(tif, fip->field_tag, &wc2, &dp);
                dir->tdir_count = wc2;
            } else {    /* Assume TIFF_VARIABLE */
                TIFFGetField(tif, fip->field_tag, &wc, &dp);
                dir->tdir_count = wc;
            }
            if (!TIFFWriteDoubleArray(tif, dir, dp))
                return 0;
        } else {
            if (wc == 1) {
                double dv;
                TIFFGetField(tif, fip->field_tag, &dv);
                if (!TIFFWriteDoubleArray(tif, dir, &dv))
                    return 0;
            } else {
                double* dp;
                TIFFGetField(tif, fip->field_tag, &dp);
                if (!TIFFWriteDoubleArray(tif, dir, dp))
                    return 0;
            }
        }
        break;
    case TIFF_ASCII:
        { 
                    char* cp;
                    if (fip->field_passcount)
                    {
                        if( wc == (uint16) TIFF_VARIABLE2 )
                            TIFFGetField(tif, fip->field_tag, &wc2, &cp);
                        else
                            TIFFGetField(tif, fip->field_tag, &wc, &cp);
                    }
                    else
                        TIFFGetField(tif, fip->field_tag, &cp);

                    dir->tdir_count = (uint32) (strlen(cp) + 1);
                    if (!TIFFWriteByteArray(tif, dir, cp))
                        return (0);
        }
        break;

        case TIFF_BYTE:
        case TIFF_SBYTE:          
        if (fip->field_passcount) {
            char* cp;
            if (wc == (uint16) TIFF_VARIABLE2) {
                TIFFGetField(tif, fip->field_tag, &wc2, &cp);
                dir->tdir_count = wc2;
            } else {    /* Assume TIFF_VARIABLE */
                TIFFGetField(tif, fip->field_tag, &wc, &cp);
                dir->tdir_count = wc;
            }
            if (!TIFFWriteByteArray(tif, dir, cp))
                return 0;
        } else {
            if (wc == 1) {
                char cv;
                TIFFGetField(tif, fip->field_tag, &cv);
                if (!TIFFWriteByteArray(tif, dir, &cv))
                    return 0;
            } else {
                char* cp;
                TIFFGetField(tif, fip->field_tag, &cp);
                if (!TIFFWriteByteArray(tif, dir, cp))
                    return 0;
            }
        }
                break;

    case TIFF_UNDEFINED:
        { char* cp;
          if (wc == (unsigned short) TIFF_VARIABLE) {
            TIFFGetField(tif, fip->field_tag, &wc, &cp);
            dir->tdir_count = wc;
          } else if (wc == (unsigned short) TIFF_VARIABLE2) {
            TIFFGetField(tif, fip->field_tag, &wc2, &cp);
            dir->tdir_count = wc2;
          } else 
            TIFFGetField(tif, fip->field_tag, &cp);
          if (!TIFFWriteByteArray(tif, dir, cp))
            return (0);
        }
        break;

        case TIFF_NOTYPE:
                break;
    }
    return (1);
}

/*
 * Setup a directory entry with either a SHORT
 * or LONG type according to the value.
 */
static void
TIFFSetupShortLong(TIFF* tif, ttag_t tag, TIFFDirEntry* dir, uint32 v)
{
    dir->tdir_tag = (uint16) tag;
    dir->tdir_count = 1;
    if (v > 0xffffL) {
        dir->tdir_type = (short) TIFF_LONG;
        dir->tdir_offset = v;
    } else {
        dir->tdir_type = (short) TIFF_SHORT;
        dir->tdir_offset = TIFFInsertData(tif, (int) TIFF_SHORT, v);
    }
}

/*
 * Setup a SHORT directory entry
 */
static void
TIFFSetupShort(TIFF* tif, ttag_t tag, TIFFDirEntry* dir, uint16 v)
{
    dir->tdir_tag = (uint16) tag;
    dir->tdir_count = 1;
    dir->tdir_type = (short) TIFF_SHORT;
    dir->tdir_offset = TIFFInsertData(tif, (int) TIFF_SHORT, v);
}
#undef MakeShortDirent

#define NITEMS(x)   (sizeof (x) / sizeof (x[0]))
/*
 * Setup a directory entry that references a
 * samples/pixel array of SHORT values and
 * (potentially) write the associated indirect
 * values.
 */
static int
TIFFWritePerSampleShorts(TIFF* tif, ttag_t tag, TIFFDirEntry* dir)
{
    uint16 buf[10], v;
    uint16* w = buf;
    uint16 i, samples = tif->tif_dir.td_samplesperpixel;
    int status;

    if (samples > NITEMS(buf)) {
        w = (uint16*) _TIFFmalloc(samples * sizeof (uint16));
        if (w == NULL) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                "No space to write per-sample shorts");
            return (0);
        }
    }
    TIFFGetField(tif, tag, &v);
    for (i = 0; i < samples; i++)
        w[i] = v;
    
    dir->tdir_tag = (uint16) tag;
    dir->tdir_type = (uint16) TIFF_SHORT;
    dir->tdir_count = samples;
    status = TIFFWriteShortArray(tif, dir, w);
    if (w != buf)
        _TIFFfree((char*) w);
    return (status);
}

/*
 * Setup a directory entry that references a samples/pixel array of ``type''
 * values and (potentially) write the associated indirect values.  The source
 * data from TIFFGetField() for the specified tag must be returned as double.
 */
static int
TIFFWritePerSampleAnys(TIFF* tif,
    TIFFDataType type, ttag_t tag, TIFFDirEntry* dir)
{
    double buf[10], v;
    double* w = buf;
    uint16 i, samples = tif->tif_dir.td_samplesperpixel;
    int status;

    if (samples > NITEMS(buf)) {
        w = (double*) _TIFFmalloc(samples * sizeof (double));
        if (w == NULL) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                "No space to write per-sample values");
            return (0);
        }
    }
    TIFFGetField(tif, tag, &v);
    for (i = 0; i < samples; i++)
        w[i] = v;
    status = TIFFWriteAnyArray(tif, type, tag, dir, samples, w);
    if (w != buf)
        _TIFFfree(w);
    return (status);
}
#undef NITEMS

/*
 * Setup a pair of shorts that are returned by
 * value, rather than as a reference to an array.
 */
static int
TIFFSetupShortPair(TIFF* tif, ttag_t tag, TIFFDirEntry* dir)
{
    uint16 v[2];

    TIFFGetField(tif, tag, &v[0], &v[1]);

    dir->tdir_tag = (uint16) tag;
    dir->tdir_type = (uint16) TIFF_SHORT;
    dir->tdir_count = 2;
    return (TIFFWriteShortArray(tif, dir, v));
}

/*
 * Setup a directory entry for an NxM table of shorts,
 * where M is known to be 2**bitspersample, and write
 * the associated indirect data.
 */
static int
TIFFWriteShortTable(TIFF* tif,
    ttag_t tag, TIFFDirEntry* dir, uint32 n, uint16** table)
{
    uint32 i, off;

    dir->tdir_tag = (uint16) tag;
    dir->tdir_type = (short) TIFF_SHORT;
    /* XXX -- yech, fool TIFFWriteData */
    dir->tdir_count = (uint32) (1L<<tif->tif_dir.td_bitspersample);
    off = tif->tif_dataoff;
    for (i = 0; i < n; i++)
        if (!TIFFWriteData(tif, dir, (char *)table[i]))
            return (0);
    dir->tdir_count *= n;
    dir->tdir_offset = off;
    return (1);
}

/*
 * Write/copy data associated with an ASCII or opaque tag value.
 */
static int
TIFFWriteByteArray(TIFF* tif, TIFFDirEntry* dir, char* cp)
{
    if (dir->tdir_count <= 4) {
        if (tif->tif_header.tiff_magic == TIFF_BIGENDIAN) {
            dir->tdir_offset = (uint32)cp[0] << 24;
            if (dir->tdir_count >= 2)
                dir->tdir_offset |= (uint32)cp[1] << 16;
            if (dir->tdir_count >= 3)
                dir->tdir_offset |= (uint32)cp[2] << 8;
            if (dir->tdir_count == 4)
                dir->tdir_offset |= cp[3];
        } else {
            dir->tdir_offset = cp[0];
            if (dir->tdir_count >= 2)
                dir->tdir_offset |= (uint32) cp[1] << 8;
            if (dir->tdir_count >= 3)
                dir->tdir_offset |= (uint32) cp[2] << 16;
            if (dir->tdir_count == 4)
                dir->tdir_offset |= (uint32) cp[3] << 24;
        }
        return 1;
    } else
        return TIFFWriteData(tif, dir, cp);
}

/*
 * Setup a directory entry of an array of SHORT
 * or SSHORT and write the associated indirect values.
 */
static int
TIFFWriteShortArray(TIFF* tif, TIFFDirEntry* dir, uint16* v)
{
    if (dir->tdir_count <= 2) {
        if (tif->tif_header.tiff_magic == TIFF_BIGENDIAN) {
            dir->tdir_offset = (uint32) v[0] << 16;
            if (dir->tdir_count == 2)
                dir->tdir_offset |= v[1] & 0xffff;
        } else {
            dir->tdir_offset = v[0] & 0xffff;
            if (dir->tdir_count == 2)
                dir->tdir_offset |= (uint32) v[1] << 16;
        }
        return (1);
    } else
        return (TIFFWriteData(tif, dir, (char*) v));
}

/*
 * Setup a directory entry of an array of LONG
 * or SLONG and write the associated indirect values.
 */
static int
TIFFWriteLongArray(TIFF* tif, TIFFDirEntry* dir, uint32* v)
{
    if (dir->tdir_count == 1) {
        dir->tdir_offset = v[0];
        return (1);
    } else
        return (TIFFWriteData(tif, dir, (char*) v));
}

/*
 * Setup a directory entry of an array of RATIONAL
 * or SRATIONAL and write the associated indirect values.
 */
static int
TIFFWriteRationalArray(TIFF* tif, TIFFDirEntry* dir, float* v)
{
    uint32 i;
    uint32* t;
    int status;

    t = (uint32*) _TIFFmalloc(2 * dir->tdir_count * sizeof (uint32));
    if (t == NULL) {
        TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
            "No space to write RATIONAL array");
        return (0);
    }
    for (i = 0; i < dir->tdir_count; i++) {
        float fv = v[i];
        int sign = 1;
        uint32 den;

        if (fv < 0) {
            if (dir->tdir_type == TIFF_RATIONAL) {
                TIFFWarningExt(tif->tif_clientdata,
                           tif->tif_name,
    "\"%s\": Information lost writing value (%g) as (unsigned) RATIONAL",
                _TIFFFieldWithTag(tif,dir->tdir_tag)->field_name,
                        fv);
                fv = 0;
            } else
                fv = -fv, sign = -1;
        }
        den = 1L;
        if (fv > 0) {
            while (fv < 1L<<(31-3) && den < 1L<<(31-3))
                fv *= 1<<3, den *= 1L<<3;
        }
        t[2*i+0] = (uint32) (sign * (fv + 0.5));
        t[2*i+1] = den;
    }
    status = TIFFWriteData(tif, dir, (char *)t);
    _TIFFfree((char*) t);
    return (status);
}

static int
TIFFWriteFloatArray(TIFF* tif, TIFFDirEntry* dir, float* v)
{
    TIFFCvtNativeToIEEEFloat(tif, dir->tdir_count, v);
    if (dir->tdir_count == 1) {
        dir->tdir_offset = *(uint32*) &v[0];
        return (1);
    } else
        return (TIFFWriteData(tif, dir, (char*) v));
}

static int
TIFFWriteDoubleArray(TIFF* tif, TIFFDirEntry* dir, double* v)
{
    TIFFCvtNativeToIEEEDouble(tif, dir->tdir_count, v);
    return (TIFFWriteData(tif, dir, (char*) v));
}

/*
 * Write an array of ``type'' values for a specified tag (i.e. this is a tag
 * which is allowed to have different types, e.g. SMaxSampleType).
 * Internally the data values are represented as double since a double can
 * hold any of the TIFF tag types (yes, this should really be an abstract
 * type tany_t for portability).  The data is converted into the specified
 * type in a temporary buffer and then handed off to the appropriate array
 * writer.
 */
static int
TIFFWriteAnyArray(TIFF* tif,
    TIFFDataType type, ttag_t tag, TIFFDirEntry* dir, uint32 n, double* v)
{
    char buf[10 * sizeof(double)];
    char* w = buf;
    int i, status = 0;

    if (n * TIFFDataWidth(type) > sizeof buf) {
        w = (char*) _TIFFmalloc(n * TIFFDataWidth(type));
        if (w == NULL) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                     "No space to write array");
            return (0);
        }
    }

    dir->tdir_tag = (uint16) tag;
    dir->tdir_type = (uint16) type;
    dir->tdir_count = n;

    switch (type) {
    case TIFF_BYTE:
        { 
            uint8* bp = (uint8*) w;
            for (i = 0; i < (int) n; i++)
                bp[i] = (uint8) v[i];
            if (!TIFFWriteByteArray(tif, dir, (char*) bp))
                goto out;
        }
        break;
    case TIFF_SBYTE:
        { 
            int8* bp = (int8*) w;
            for (i = 0; i < (int) n; i++)
                bp[i] = (int8) v[i];
            if (!TIFFWriteByteArray(tif, dir, (char*) bp))
                goto out;
        }
        break;
    case TIFF_SHORT:
        {
            uint16* bp = (uint16*) w;
            for (i = 0; i < (int) n; i++)
                bp[i] = (uint16) v[i];
            if (!TIFFWriteShortArray(tif, dir, (uint16*)bp))
                goto out;
        }
        break;
    case TIFF_SSHORT:
        { 
            int16* bp = (int16*) w;
            for (i = 0; i < (int) n; i++)
                bp[i] = (int16) v[i];
            if (!TIFFWriteShortArray(tif, dir, (uint16*)bp))
                goto out;
        }
        break;
    case TIFF_LONG:
        {
            uint32* bp = (uint32*) w;
            for (i = 0; i < (int) n; i++)
                bp[i] = (uint32) v[i];
            if (!TIFFWriteLongArray(tif, dir, bp))
                goto out;
        }
        break;
    case TIFF_SLONG:
        {
            int32* bp = (int32*) w;
            for (i = 0; i < (int) n; i++)
                bp[i] = (int32) v[i];
            if (!TIFFWriteLongArray(tif, dir, (uint32*) bp))
                goto out;
        }
        break;
    case TIFF_FLOAT:
        { 
            float* bp = (float*) w;
            for (i = 0; i < (int) n; i++)
                bp[i] = (float) v[i];
            if (!TIFFWriteFloatArray(tif, dir, bp))
                goto out;
        }
        break;
    case TIFF_DOUBLE:
                {
                    if( !TIFFWriteDoubleArray(tif, dir, v))
                        goto out;
                }
        break;
    default:
        /* TIFF_NOTYPE */
        /* TIFF_ASCII */
        /* TIFF_UNDEFINED */
        /* TIFF_RATIONAL */
        /* TIFF_SRATIONAL */
        goto out;
    }
    status = 1;
 out:
    if (w != buf)
        _TIFFfree(w);
    return (status);
}

static int
TIFFWriteTransferFunction(TIFF* tif, TIFFDirEntry* dir)
{
    TIFFDirectory* td = &tif->tif_dir;
    tsize_t n = (1L<<td->td_bitspersample) * sizeof (uint16);
    uint16** tf = td->td_transferfunction;
    int ncols;

    /*
     * Check if the table can be written as a single column,
     * or if it must be written as 3 columns.  Note that we
     * write a 3-column tag if there are 2 samples/pixel and
     * a single column of data won't suffice--hmm.
     */
    switch (td->td_samplesperpixel - td->td_extrasamples) {
    default:    if (_TIFFmemcmp(tf[0], tf[2], n)) { ncols = 3; break; }
    case 2:     if (_TIFFmemcmp(tf[0], tf[1], n)) { ncols = 3; break; }
    case 1: case 0: ncols = 1;
    }
    return (TIFFWriteShortTable(tif,
        TIFFTAG_TRANSFERFUNCTION, dir, ncols, tf));
}

static int
TIFFWriteInkNames(TIFF* tif, TIFFDirEntry* dir)
{
    TIFFDirectory* td = &tif->tif_dir;

    dir->tdir_tag = TIFFTAG_INKNAMES;
    dir->tdir_type = (short) TIFF_ASCII;
    dir->tdir_count = td->td_inknameslen;
    return (TIFFWriteByteArray(tif, dir, td->td_inknames));
}

/*
 * Write a contiguous directory item.
 */
static int
TIFFWriteData(TIFF* tif, TIFFDirEntry* dir, char* cp)
{
    tsize_t cc;

    if (tif->tif_flags & TIFF_SWAB) {
        switch (dir->tdir_type) {
        case TIFF_SHORT:
        case TIFF_SSHORT:
            TIFFSwabArrayOfShort((uint16*) cp, dir->tdir_count);
            break;
        case TIFF_LONG:
        case TIFF_SLONG:
        case TIFF_FLOAT:
            TIFFSwabArrayOfLong((uint32*) cp, dir->tdir_count);
            break;
        case TIFF_RATIONAL:
        case TIFF_SRATIONAL:
            TIFFSwabArrayOfLong((uint32*) cp, 2*dir->tdir_count);
            break;
        case TIFF_DOUBLE:
            TIFFSwabArrayOfDouble((double*) cp, dir->tdir_count);
            break;
        }
    }
    dir->tdir_offset = tif->tif_dataoff;
    cc = dir->tdir_count * TIFFDataWidth((TIFFDataType) dir->tdir_type);
    if (SeekOK(tif, dir->tdir_offset) &&
        WriteOK(tif, cp, cc)) {
        tif->tif_dataoff += (cc + 1) & ~1;
        return (1);
    }
    TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
             "Error writing data for field \"%s\"",
    _TIFFFieldWithTag(tif, dir->tdir_tag)->field_name);
    return (0);
}

/*
 * Similar to TIFFWriteDirectory(), but if the directory has already
 * been written once, it is relocated to the end of the file, in case it
 * has changed in size.  Note that this will result in the loss of the 
 * previously used directory space. 
 */ 

int 
TIFFRewriteDirectory( TIFF *tif )
{
    static const char module[] = "TIFFRewriteDirectory";

    /* We don't need to do anything special if it hasn't been written. */
    if( tif->tif_diroff == 0 )
        return TIFFWriteDirectory( tif );

    /*
    ** Find and zero the pointer to this directory, so that TIFFLinkDirectory
    ** will cause it to be added after this directories current pre-link.
    */
    
    /* Is it the first directory in the file? */
    if (tif->tif_header.tiff_diroff == tif->tif_diroff) 
    {
        tif->tif_header.tiff_diroff = 0;
        tif->tif_diroff = 0;

        TIFFSeekFile(tif, (toff_t)(TIFF_MAGIC_SIZE+TIFF_VERSION_SIZE),
             SEEK_SET);
        if (!WriteOK(tif, &(tif->tif_header.tiff_diroff), 
                     sizeof (tif->tif_diroff))) 
        {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                     "Error updating TIFF header");
            return (0);
        }
    }
    else
    {
        toff_t  nextdir, off;

    nextdir = tif->tif_header.tiff_diroff;
    do {
        uint16 dircount;

        if (!SeekOK(tif, nextdir) ||
            !ReadOK(tif, &dircount, sizeof (dircount))) {
            TIFFErrorExt(tif->tif_clientdata, module,
                     "Error fetching directory count");
            return (0);
        }
        if (tif->tif_flags & TIFF_SWAB)
            TIFFSwabShort(&dircount);
        (void) TIFFSeekFile(tif,
            dircount * sizeof (TIFFDirEntry), SEEK_CUR);
        if (!ReadOK(tif, &nextdir, sizeof (nextdir))) {
            TIFFErrorExt(tif->tif_clientdata, module,
                     "Error fetching directory link");
            return (0);
        }
        if (tif->tif_flags & TIFF_SWAB)
            TIFFSwabLong(&nextdir);
    } while (nextdir != tif->tif_diroff && nextdir != 0);
        off = TIFFSeekFile(tif, 0, SEEK_CUR); /* get current offset */
        (void) TIFFSeekFile(tif, off - (toff_t)sizeof(nextdir), SEEK_SET);
        tif->tif_diroff = 0;
    if (!WriteOK(tif, &(tif->tif_diroff), sizeof (nextdir))) {
        TIFFErrorExt(tif->tif_clientdata, module,
                 "Error writing directory link");
        return (0);
    }
    }

    /*
    ** Now use TIFFWriteDirectory() normally.
    */

    return TIFFWriteDirectory( tif );
}


/*
 * Link the current directory into the directory chain for the file.
 */
static int
TIFFLinkDirectory(TIFF* tif)
{
    static const char module[] = "TIFFLinkDirectory";
    toff_t nextdir;
    toff_t diroff, off;

    tif->tif_diroff = (TIFFSeekFile(tif, (toff_t) 0, SEEK_END)+1) &~ 1;
    diroff = tif->tif_diroff;
    if (tif->tif_flags & TIFF_SWAB)
        TIFFSwabLong(&diroff);

    /*
     * Handle SubIFDs
     */
        if (tif->tif_flags & TIFF_INSUBIFD) {
        (void) TIFFSeekFile(tif, tif->tif_subifdoff, SEEK_SET);
        if (!WriteOK(tif, &diroff, sizeof (diroff))) {
            TIFFErrorExt(tif->tif_clientdata, module,
                     "%s: Error writing SubIFD directory link",
                     tif->tif_name);
            return (0);
        }
        /*
         * Advance to the next SubIFD or, if this is
         * the last one configured, revert back to the
         * normal directory linkage.
         */
        if (--tif->tif_nsubifd)
            tif->tif_subifdoff += sizeof (diroff);
        else
            tif->tif_flags &= ~TIFF_INSUBIFD;
        return (1);
    }

    if (tif->tif_header.tiff_diroff == 0) {
        /*
         * First directory, overwrite offset in header.
         */
        tif->tif_header.tiff_diroff = tif->tif_diroff;
        (void) TIFFSeekFile(tif,
                    (toff_t)(TIFF_MAGIC_SIZE+TIFF_VERSION_SIZE),
                                    SEEK_SET);
        if (!WriteOK(tif, &diroff, sizeof (diroff))) {
            TIFFErrorExt(tif->tif_clientdata, tif->tif_name,
                     "Error writing TIFF header");
            return (0);
        }
        return (1);
    }
    /*
     * Not the first directory, search to the last and append.
     */
    nextdir = tif->tif_header.tiff_diroff;
    do {
        uint16 dircount;

        if (!SeekOK(tif, nextdir) ||
            !ReadOK(tif, &dircount, sizeof (dircount))) {
            TIFFErrorExt(tif->tif_clientdata, module,
                     "Error fetching directory count");
            return (0);
        }
        if (tif->tif_flags & TIFF_SWAB)
            TIFFSwabShort(&dircount);
        (void) TIFFSeekFile(tif,
            dircount * sizeof (TIFFDirEntry), SEEK_CUR);
        if (!ReadOK(tif, &nextdir, sizeof (nextdir))) {
            TIFFErrorExt(tif->tif_clientdata, module,
                     "Error fetching directory link");
            return (0);
        }
        if (tif->tif_flags & TIFF_SWAB)
            TIFFSwabLong(&nextdir);
    } while (nextdir != 0);
        off = TIFFSeekFile(tif, 0, SEEK_CUR); /* get current offset */
        (void) TIFFSeekFile(tif, off - (toff_t)sizeof(nextdir), SEEK_SET);
    if (!WriteOK(tif, &diroff, sizeof (diroff))) {
        TIFFErrorExt(tif->tif_clientdata, module,
                 "Error writing directory link");
        return (0);
    }
    return (1);
}

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