diff -r 000000000000 -r 6474c204b198 image/decoders/nsPNGDecoder.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/image/decoders/nsPNGDecoder.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,136 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsPNGDecoder_h__
+#define nsPNGDecoder_h__
+
+#include "Decoder.h"
+
+#include "gfxTypes.h"
+
+#include "nsCOMPtr.h"
+
+#include "png.h"
+
+#include "qcms.h"
+
+namespace mozilla {
+namespace image {
+class RasterImage;
+
+class nsPNGDecoder : public Decoder
+{
+public:
+  nsPNGDecoder(RasterImage &aImage);
+  virtual ~nsPNGDecoder();
+
+  virtual void InitInternal();
+  virtual void WriteInternal(const char* aBuffer, uint32_t aCount, DecodeStrategy aStrategy);
+  virtual Telemetry::ID SpeedHistogram();
+
+  void CreateFrame(png_uint_32 x_offset, png_uint_32 y_offset,
+                   int32_t width, int32_t height,
+                   gfxImageFormat format);
+  void EndImageFrame();
+
+  // Check if PNG is valid ICO (32bpp RGBA)
+  // http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
+  bool IsValidICO() const
+  {
+    // If there are errors in the call to png_get_IHDR, the error_callback in
+    // nsPNGDecoder.cpp is called.  In this error callback we do a longjmp, so
+    // we need to save the jump buffer here. Oterwise we'll end up without a
+    // proper callstack.
+    if (setjmp(png_jmpbuf(mPNG))) {
+      // We got here from a longjmp call indirectly from png_get_IHDR
+      return false;
+    }
+
+    png_uint_32
+        png_width,  // Unused
+        png_height; // Unused
+
+    int png_bit_depth,
+        png_color_type;
+
+    if (png_get_IHDR(mPNG, mInfo, &png_width, &png_height, &png_bit_depth,
+                     &png_color_type, nullptr, nullptr, nullptr)) {
+
+      return ((png_color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+               png_color_type == PNG_COLOR_TYPE_RGB) &&
+              png_bit_depth == 8);
+    } else {
+      return false;
+    }
+  }
+
+public:
+  png_structp mPNG;
+  png_infop mInfo;
+  nsIntRect mFrameRect;
+  uint8_t *mCMSLine;
+  uint8_t *interlacebuf;
+  qcms_profile *mInProfile;
+  qcms_transform *mTransform;
+
+  gfxImageFormat format;
+
+  // For size decodes
+  uint8_t mSizeBytes[8]; // Space for width and height, both 4 bytes
+  uint32_t mHeaderBytesRead;
+
+  // whether CMS or premultiplied alpha are forced off
+  uint32_t mCMSMode;
+
+  uint8_t mChannels;
+  bool mFrameHasNoAlpha;
+  bool mFrameIsHidden;
+  bool mDisablePremultipliedAlpha;
+
+  struct AnimFrameInfo
+  {
+    AnimFrameInfo();
+#ifdef PNG_APNG_SUPPORTED
+    AnimFrameInfo(png_structp aPNG, png_infop aInfo);
+#endif
+
+    FrameBlender::FrameDisposalMethod mDispose;
+    FrameBlender::FrameBlendMethod mBlend;
+    int32_t mTimeout;
+  };
+
+  AnimFrameInfo mAnimInfo;
+
+  // The number of frames we've finished.
+  uint32_t mNumFrames;
+  
+  /*
+   * libpng callbacks
+   *
+   * We put these in the class so that they can access protected members.
+   */
+  static void PNGAPI info_callback(png_structp png_ptr, png_infop info_ptr);
+  static void PNGAPI row_callback(png_structp png_ptr, png_bytep new_row,
+                                  png_uint_32 row_num, int pass);
+#ifdef PNG_APNG_SUPPORTED
+  static void PNGAPI frame_info_callback(png_structp png_ptr,
+                                         png_uint_32 frame_num);
+#endif
+  static void PNGAPI end_callback(png_structp png_ptr, png_infop info_ptr);
+  static void PNGAPI error_callback(png_structp png_ptr,
+                                    png_const_charp error_msg);
+  static void PNGAPI warning_callback(png_structp png_ptr,
+                                      png_const_charp warning_msg);
+
+  // This is defined in the PNG spec as an invariant. We use it to
+  // do manual validation without libpng.
+  static const uint8_t pngSignatureBytes[];
+};
+
+} // namespace image
+} // namespace mozilla
+
+#endif // nsPNGDecoder_h__