From: Lars Magne Ingebrigtsen <larsi@gnus.org>
Date: Thu, 15 Aug 2013 17:20:06 +0000 (+0200)
Subject: (imagemagick_compute_animated_image): Respect the GIF disposal methods.
X-Git-Tag: emacs-24.3.90~173^2^2~42^2~45^2~387^2~1686^2~226
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=a5b5f73f32a8af8a45a252ed13a381d7526ad1b7;p=emacs.git

(imagemagick_compute_animated_image): Respect the GIF disposal methods.
---

diff --git a/src/ChangeLog b/src/ChangeLog
index c12b32ebc71..028c33848a4 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,8 @@
+2013-08-15  Lars Magne Ingebrigtsen  <larsi@gnus.org>
+
+	* image.c (imagemagick_compute_animated_image): Respect the GIF
+	disposal methods.
+
 2013-08-15  Ken Brown  <kbrown@cornell.edu>
 
 	* emacs.c (main): Update comment about G_SLICE_ALWAYS_MALLOC.
diff --git a/src/image.c b/src/image.c
index 3cab72edf74..3c5ee4ce66f 100644
--- a/src/image.c
+++ b/src/image.c
@@ -7887,17 +7887,20 @@ imagemagick_compute_animated_image (MagickWand *super_wand, int ino)
   else
     composite_wand = animation_cache;
 
-  for (i = max (1, animation_index); i <= ino; i++)
+  for (i = max (1, animation_index + 1); i <= ino; i++)
     {
       MagickWand *sub_wand;
       PixelIterator *source_iterator, *dest_iterator;
       PixelWand **source, **dest;
       size_t source_width, dest_width;
       MagickPixelPacket pixel;
+      DisposeType dispose;
 
       MagickSetIteratorIndex (super_wand, i);
       sub_wand = MagickGetImage (super_wand);
 
+      dispose = MagickGetImageDispose (sub_wand);
+
       source_iterator = NewPixelIterator (sub_wand);
       if (! source_iterator)
 	{
@@ -7926,12 +7929,20 @@ imagemagick_compute_animated_image (MagickWand *super_wand, int ino)
 	  dest = PixelGetNextIteratorRow (dest_iterator, &dest_width);
 	  for (x = 0; x < source_width; x++)
 	    {
-	      /* Copy over non-transparent pixels. */
-	      if (PixelGetAlpha (source[x]))
+	      if (dispose == BackgroundDispose)
 		{
 		  PixelGetMagickColor (source[x], &pixel);
 		  PixelSetMagickColor (dest[x], &pixel);
 		}
+	      else
+		{
+		  /* Copy over non-transparent pixels. */
+		  if (PixelGetAlpha (source[x]))
+		    {
+		      PixelGetMagickColor (source[x], &pixel);
+		      PixelSetMagickColor (dest[x], &pixel);
+		    }
+		}
 	    }
 	  PixelSyncIterator(dest_iterator);
 	}