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TIFF and LibTiff Mail List Archive

Thread

2005.03.29 23:08 "[Tiff] [patch] little things", by Ron
2005.03.30 13:48 "Re: [Tiff] [patch] little things", by Andrey Kiselev

2005.03.29 23:08 "[Tiff] [patch] little things", by Ron

Hi,

I've got a couple of little things first off, all re current cvs HEAD. Unless I'm mistaken, we can't just add the exif tags in a neat block to tif_dirinfo.c, we rely on that array being ordered by tag and bsearch it later. The first hunk below fixes that for the exif tags that were added, I've not checked the DNG ones that were also added. The second hunk changes find by name to use lsearch, since the array is ordered by key not name.

I'm also using the following in the TIFFClientOpen replacement I posted previously, (so it won't apply cleanly to HEAD except by hand). The problem it fixes is pathological but potentially real I think. If you try to write a tiff to a filename that already exists, we try to read the header from the file instead of just writing the one we have. If the byte sex of the header on file is different to the tiff you think you are about to write, it would seem things might go pear shaped. That may not be the only way, so its simpler and safer to just not try to read it if we are writing I think, as a minimal patch something like so:

        /*
         * Read in TIFF header.
         */

-       if (!ReadOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {
+       if ( mode[ 0 ] == 'w' ||
+            !ReadOK(tif, &tif->tif_header, sizeof (TIFFHeader))) {

                if (tif->tif_mode == O_RDONLY) {
                        TIFFError(name, "Cannot read TIFF header");
                        goto bad;

Pass by value for the custom tags was a very welcome addition too, thanks Andrey!

Ron

Index: libtiff/tif_dirinfo.c

=================================================================== RCS file: /cvs/maptools/cvsroot/libtiff/libtiff/tif_dirinfo.c,v retrieving revision 1.40

diff -u -r1.40 tif_dirinfo.c

--- libtiff/tif_dirinfo.c       18 Mar 2005 14:27:30 -0000      1.40
+++ libtiff/tif_dirinfo.c       29 Mar 2005 22:33:31 -0000

@@ -247,20 +247,18 @@
 /* end Pixar tags */

     { TIFFTAG_RICHTIFFIPTC, -1, -3, TIFF_LONG,   FIELD_RICHTIFFIPTC, 
       FALSE,    TRUE,   "RichTIFFIPTC" },
-/* begin EXIF tags */
-    { TIFFTAG_EXIFIFD,         1, 1,   TIFF_LONG,      FIELD_CUSTOM,
-      FALSE,   FALSE,  "EXIFIFDOffset" },
-    { TIFFTAG_GPSIFD,          1, 1,   TIFF_LONG,      FIELD_CUSTOM,
-      FALSE,   FALSE,  "GPSIFDOffset" },
-    { TIFFTAG_INTEROPERABILITYIFD,     1, 1,   TIFF_LONG,      FIELD_CUSTOM,
-      FALSE,   FALSE,  "InteroperabilityIFDOffset" },
-/* end EXIF tags */
     { TIFFTAG_PHOTOSHOP,    -1, -3, TIFF_BYTE,   FIELD_PHOTOSHOP, 
       FALSE,    TRUE,   "Photoshop" },
+    { TIFFTAG_EXIFIFD,         1, 1,   TIFF_LONG,      FIELD_CUSTOM,
+      FALSE,   FALSE,  "EXIFIFDOffset" },
     { TIFFTAG_ICCPROFILE,      -1, -3, TIFF_UNDEFINED, FIELD_ICCPROFILE,
       FALSE,   TRUE,   "ICC Profile" },
+    { TIFFTAG_GPSIFD,          1, 1,   TIFF_LONG,      FIELD_CUSTOM,
+      FALSE,   FALSE,  "GPSIFDOffset" },
     { TIFFTAG_STONITS,          1, 1, TIFF_DOUBLE,     FIELD_STONITS,
       FALSE,   FALSE,  "StoNits" },
+    { TIFFTAG_INTEROPERABILITYIFD,     1, 1,   TIFF_LONG,      FIELD_CUSTOM,
+      FALSE,   FALSE,  "InteroperabilityIFDOffset" },

 /* begin DNG tags */

     { TIFFTAG_DNGVERSION,      4, 4,   TIFF_BYTE,      FIELD_CUSTOM, 

       FALSE,   FALSE,  "DNGVersion" },

@@ -604,7 +602,7 @@
             TIFFFieldInfo key = {0, 0, 0, 0, 0, 0, 0, 0};
             key.field_name = (char *)field_name;
             key.field_type = dt;

-            return((const TIFFFieldInfo *) bsearch(&key, 
+            return((const TIFFFieldInfo *) lsearch(&key, 

                                                   tif->tif_fieldinfo,
                                                   tif->tif_nfields,
                                                   sizeof(TIFFFieldInfo),