From: glennrp <glennrp@git.imagemagick.org>
Date: Fri, 11 Mar 2011 18:03:44 +0000 (+0000)
Subject: Don't store background color in the colormap if there are already 256
X-Git-Tag: 7.0.1-0~7995
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=a080bc32a4a8b2ffec83fd836a28753959175363;p=imagemagick

Don't store background color in the colormap if there are already 256

colors present and we are writing a PNG8.
---

diff --git a/ChangeLog b/ChangeLog
index ce1827131..aa1985536 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2011-03-11  6.6.8-4 Glenn Randers-Pehrson <glennrp@image...>
+  * Don't try to store a bKGD chunk in a PNG8 when there are already
+    256 colors in the palette and the background colors is not in that
+    palette (reference
+    http://www.imagemagick.org/discourse-server/viewtopic.php?f=3&t=18199);
+
 2011-03-10  6.6.8-4 Cristy  <quetzlzacatenango@image...>
   * Fx is a mathematicals function.  Do not treat transparency as black.
 
diff --git a/coders/png.c b/coders/png.c
index b4eb16cf0..cd66d0dc7 100644
--- a/coders/png.c
+++ b/coders/png.c
@@ -7189,8 +7189,7 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
           */
           for (i=0; i<number_opaque; i++)
           {
-             if (IsColorEqual(opaque+i,
-                &image->background_color))
+             if (IsColorEqual(opaque+i, &image->background_color))
              break;
           }
 
@@ -7200,10 +7199,20 @@ static MagickBooleanType WriteOnePNGImage(MngInfo *mng_info,
                opaque[i].opacity = OpaqueOpacity;
                number_opaque++;
             }
+          else if (logging != MagickFalse)
+              (void) LogMagickEvent(CoderEvent,GetMagickModule(),
+                  "      No room in the colormap to add background color");
        }
 
      image_colors=number_opaque+number_transparent+number_semitransparent;
 
+     if (mng_info->write_png8 != MagickFalse && image_colors > 256)
+       {
+         /* No room for the background color; remove it. */
+         number_opaque--;
+         image_colors--;
+       }
+
      if (logging != MagickFalse)
        {
          if (image_colors > 256)