Submitted By: Andrew Benton <b3nton@gmail.com>
Date: 2011-12-20
Initial Package Version: 1
Upstream Status: From Mozilla Bugzilla bug #682677
Origin: https://bug682677.bugzilla.mozilla.org/attachment.cgi?id=558454
Description: Fixes compiling firefox-9.0 with libpng-1.5.6 installed

diff -Naur mozilla-release~/modules/libpr0n/decoders/nsICODecoder.cpp mozilla-release/modules/libpr0n/decoders/nsICODecoder.cpp
--- mozilla-release~/modules/libpr0n/decoders/nsICODecoder.cpp	2011-12-16 20:29:37.000000000 +0000
+++ mozilla-release/modules/libpr0n/decoders/nsICODecoder.cpp	2011-12-20 19:42:00.529798093 +0000
@@ -385,8 +385,7 @@
 
     // Raymond Chen says that 32bpp only are valid PNG ICOs
     // http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
-    if (static_cast<nsPNGDecoder*>(mContainedDecoder.get())->HasValidInfo() && 
-        static_cast<nsPNGDecoder*>(mContainedDecoder.get())->GetPixelDepth() != 32) {
+    if (!static_cast<nsPNGDecoder*>(mContainedDecoder.get())->IsValidICO()) {
       PostDataError();
     }
     return;
diff -Naur mozilla-release~/modules/libpr0n/decoders/nsPNGDecoder.h mozilla-release/modules/libpr0n/decoders/nsPNGDecoder.h
--- mozilla-release~/modules/libpr0n/decoders/nsPNGDecoder.h	2011-12-16 20:29:37.000000000 +0000
+++ mozilla-release/modules/libpr0n/decoders/nsPNGDecoder.h	2011-12-20 19:42:00.529798093 +0000
@@ -73,19 +73,12 @@
 
   void EndImageFrame();
 
-  // Checks if the info header contains valid information
-  bool HasValidInfo() const 
+  // Check if PNG is valid ICO (32bpp RGBA)
+  // http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
+  bool IsValidICO() const
   {
-    return mInfo && mInfo->valid;
-  }
-
-  // Obtain the pixel depth if available or 0 otherwise
-  PRInt32 GetPixelDepth() const
-  {
-    if (!mInfo) {
-      return 0;
-    }
-    return mInfo->pixel_depth;
+    return (png_get_color_type(mPNG, mInfo) == PNG_COLOR_TYPE_RGB_ALPHA &&
+            png_get_bit_depth(mPNG, mInfo) == 8);
   }
 
 public: