GraphicsMagick: PNG: Fixes for writing/reading EXIF. Especially...

changeset 60b132017fce in /hg/GraphicsMagick
details: http://hg.GraphicsMagick.org/hg/GraphicsMagick?cmd=changeset;node=60b132017fce
summary: PNG: Fixes for writing/reading EXIF.  Especially for libpng 1.6.31 or later.

diffstat:

 ChangeLog          |  5 +++++
 coders/png.c       |  9 ++++++---
 www/Changelog.html |  7 +++++++
 3 files changed, 18 insertions(+), 3 deletions(-)

diffs (62 lines):

diff -r ce1d625ff845 -r 60b132017fce ChangeLog
--- a/ChangeLog	Sat Mar 18 10:12:16 2023 -0500
+++ b/ChangeLog	Sat Mar 18 18:16:06 2023 -0500
@@ -1,3 +1,8 @@
+2023-03-18  Fojtik Jaroslav  <[email protected]>
+
+	* coders/png.c There were 2 defects that prevented eXIf chunk
+        to be read.
+
 2023-03-18  Fojtik Jaroslav  <[email protected]>
 
 	* coders/png.c Variable "png_byte unused_chunks" should be const
diff -r ce1d625ff845 -r 60b132017fce coders/png.c
--- a/coders/png.c	Sat Mar 18 10:12:16 2023 -0500
+++ b/coders/png.c	Sat Mar 18 18:16:06 2023 -0500
@@ -1396,8 +1396,8 @@
       s=chunk->data;
 
       if (chunk->size > 6 &&
-          (s[0] == 'E' || s[1] == 'x' || s[2] == 'i' ||
-           s[3] == 'f' || s[4] == '\0' || s[5] == '\0'))
+          (s[0] == 'E' && s[1] == 'x' && s[2] == 'i' &&
+           s[3] == 'f' && s[4] == '\0' && s[5] == '\0'))
         {
           /*
             Skip over "Exif\0\0" if already present
@@ -1577,6 +1577,9 @@
       115,  67,  65,  76, '\0',   /* sCAL */
       115,  80,  76,  84, '\0',   /* sPLT */
       116,  73,  77,  69, '\0',   /* tIME */
+#ifdef PNG_READ_eXIf_SUPPORTED /* Enforce custom eXIf processing to override default one. */
+      101,  88,  73, 102, '\0',   /* eXIf*/
+#endif
 #ifdef PNG_APNG_SUPPORTED /* libpng was built with APNG patch; */
                           /* ignore the APNG chunks */
        97,  99,  84,  76, '\0',   /* acTL */
@@ -1959,7 +1962,7 @@
                                 intent+1);
       }
   }
-#endif
+#endif /* if defined(PNG_READ_sRGB_SUPPORTED) */
   {
     double
       file_gamma;
diff -r ce1d625ff845 -r 60b132017fce www/Changelog.html
--- a/www/Changelog.html	Sat Mar 18 10:12:16 2023 -0500
+++ b/www/Changelog.html	Sat Mar 18 18:16:06 2023 -0500
@@ -40,6 +40,13 @@
 <p>2023-03-18  Fojtik Jaroslav  &lt;<a class="reference external" href="mailto:JaFojtik&#37;&#52;&#48;yandex&#46;com">JaFojtik<span>&#64;</span>yandex<span>&#46;</span>com</a>&gt;</p>
 <blockquote>
 <ul class="simple">
+<li><p>coders/png.c There were 2 defects that prevented eXIf chunk
+to be read.</p></li>
+</ul>
+</blockquote>
+<p>2023-03-18  Fojtik Jaroslav  &lt;<a class="reference external" href="mailto:JaFojtik&#37;&#52;&#48;yandex&#46;com">JaFojtik<span>&#64;</span>yandex<span>&#46;</span>com</a>&gt;</p>
+<blockquote>
+<ul class="simple">
 <li><p>coders/png.c Variable &quot;png_byte unused_chunks&quot; should be const
 and not be placed on a stack.</p></li>
 </ul>