Fix for 76230, some GIFs don't display. r=pavlov, sr=hyatt

git-svn-id: svn://10.0.0.236/trunk@93692 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/modules/libpr0n/decoders/gif/GIF2.cpp

@@ -1225,6 +1225,12 @@ int gif_write(gif_struct *gs, const PRUint8 *buf, PRUint32 len)
                 gs->screen_width = width;
                 gs->x_offset = 0;
                 gs->y_offset = 0;
+                
+              (*gs->GIFCallback_BeginGIF)(
+                gs->clientptr,
+                gs->screen_width, 
+                gs->screen_height,
+                gs->screen_bgcolor);
             }
             /* Work around more broken GIF files that have zero image
                width or height */

mozilla/modules/libpr0n/decoders/gif/nsGIFDecoder2.cpp

@@ -235,6 +235,11 @@ int BeginGIF(
   PRUint32 aLogicalScreenHeight,
   PRUint8  aBackgroundRGBIndex)
 {
+  // If we have passed an illogical screen size, bail and hope that we'll get
+  // set later by the first frame's local image header.
+  if(aLogicalScreenWidth == 0 || aLogicalScreenHeight == 0)
+    return 0;
+    
   // copy GIF info into imagelib structs
   nsGIFDecoder2 *decoder = NS_STATIC_CAST(nsGIFDecoder2*, aClientData);