GraphicsMagick: SetImageInfo(): Avoid creating temporary files d...

changeset ed73da6ca2e7 in /hg/GraphicsMagick
details: http://hg.GraphicsMagick.org/hg/GraphicsMagick?cmd=changeset;node=ed73da6ca2e7
summary: SetImageInfo(): Avoid creating temporary files due to compressed input when not necessary.

diffstat:

 ChangeLog          |   5 +++++
 magick/image.c     |  27 ++++++++++++++++++++++++++-
 www/Changelog.html |   4 ++++
 3 files changed, 35 insertions(+), 1 deletions(-)

diffs (87 lines):

diff -r 62cbf900c9ca -r ed73da6ca2e7 ChangeLog
--- a/ChangeLog	Tue Nov 01 11:00:10 2022 -0500
+++ b/ChangeLog	Tue Nov 01 13:45:58 2022 -0500
@@ -1,5 +1,10 @@
 2022-11-01  Bob Friesenhahn  <[email protected]>
 
+	* magick/image.c (SetImageInfo): Avoid creating temporary files
+	when reading files with .bz2, .gz, .svgz, and .Z extensions if the
+	format is non-ambiguous based on the file extension, and the
+	reader does not require seeking.
+
 	* magick/magick.c (MagickToMime): Add MIME mappings for apng,
 	avif, bmp, ico, and webp.
 
diff -r 62cbf900c9ca -r ed73da6ca2e7 magick/image.c
--- a/magick/image.c	Tue Nov 01 11:00:10 2022 -0500
+++ b/magick/image.c	Tue Nov 01 13:45:58 2022 -0500
@@ -3134,14 +3134,21 @@
   */
   if (*magic == '\0')
     {
+      MagickBool
+        compressed_extension = MagickFalse;
+
       /* Restore p to end of modified filename */
       p=image_info->filename+Max((long) strlen(image_info->filename)-1,0);
 
       while ((*p != '.') && (p > (image_info->filename+1)))
         p--;
+
       if ((LocaleCompare(p,".gz") == 0) ||
           (LocaleCompare(p,".Z") == 0) ||
           (LocaleCompare(p,".bz2") == 0))
+        compressed_extension = MagickTrue;
+
+      if (compressed_extension)
         do
           {
             p--;
@@ -3197,7 +3204,22 @@
           magick_info=GetMagickInfo(magic,exception);
           if (magick_info != (const MagickInfo *) NULL)
             {
-              if (magick_info->extension_treatment == IgnoreExtensionTreatment)
+              /*
+                For compressed files with expected extensions
+                (e.g. name.ext.gz) we have already deduced the
+                expected format based on the base file extension, and
+                if the extension is considered to be a good hint, and
+                if seekable_stream is false for that format, use
+                "affirm" in order to avoid using a temporary file.
+              */
+              if (LocaleCompare(magick_info->name,"SVGZ") == 0)
+                compressed_extension = MagickTrue;
+
+              if ((magick_info->extension_treatment == HintExtensionTreatment) &&
+                  (magick_info->seekable_stream == MagickFalse) &&
+                  (compressed_extension))
+                image_info->affirm=MagickTrue;
+              else if (magick_info->extension_treatment == IgnoreExtensionTreatment)
                 exclude=MagickTrue;
               else if (magick_info->extension_treatment == ObeyExtensionTreatment)
                 image_info->affirm=MagickTrue;
@@ -3226,6 +3248,9 @@
           DestroyImage(image);
           return(MagickFail);
         }
+      /*
+        FIXME: Avoid creating temporary files unless absolutely necessary!
+      */
       if (!BlobIsSeekable(image))
         {
           /*
diff -r 62cbf900c9ca -r ed73da6ca2e7 www/Changelog.html
--- a/www/Changelog.html	Tue Nov 01 11:00:10 2022 -0500
+++ b/www/Changelog.html	Tue Nov 01 13:45:58 2022 -0500
@@ -40,6 +40,10 @@
 <p>2022-11-01  Bob Friesenhahn  &lt;<a class="reference external" href="mailto:bfriesen&#37;&#52;&#48;simple&#46;dallas&#46;tx&#46;us">bfriesen<span>&#64;</span>simple<span>&#46;</span>dallas<span>&#46;</span>tx<span>&#46;</span>us</a>&gt;</p>
 <blockquote>
 <ul class="simple">
+<li><p>magick/image.c (SetImageInfo): Avoid creating temporary files
+when reading files with .bz2, .gz, .svgz, and .Z extensions if the
+format is non-ambiguous based on the file extension, and the
+reader does not require seeking.</p></li>
 <li><p>magick/magick.c (MagickToMime): Add MIME mappings for apng,
 avif, bmp, ico, and webp.</p></li>
 </ul>