Allow ico decoder to decode PNG sub-images.

src/images/SkImageDecoder_libico.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkImageDecoder.h"
@@ skipping 134 matching lines @@
     int w = readByte(buf, 6 + choice*16);
     int h = readByte(buf, 7 + choice*16);
     int colorCount = readByte(buf, 8 + choice*16);
     //int reservedToo = readByte(buf, 9 + choice*16);   //0
     //int planes = read2Bytes(buf, 10 + choice*16);       //1 - but often 0
     //int fakeBitCount = read2Bytes(buf, 12 + choice*16); //should be real - usually 0
     int size = read4Bytes(buf, 14 + choice*16);           //matters?
     int offset = read4Bytes(buf, 18 + choice*16);
     if ((size_t)(offset + size) > length)
         return false;
+
+    // Check to see if this is a PNG image inside the ICO
+    {
+        SkMemoryStream subStream(buf + offset, size, false);
+        SkAutoTDelete<SkImageDecoder> otherDecoder(SkImageDecoder::Factory(&subStream));
+        if (otherDecoder.get() != NULL) {
+            // Set fields on the other decoder to be the same as this one.
+            this->copyFieldsToOther(otherDecoder.get());
+            if(otherDecoder->decode(&subStream, bm, this->getDefaultPref(), mode)) {
+                return true;
+            }
+        }
+    }
+
     //int infoSize = read4Bytes(buf, offset);             //40
     //int width = read4Bytes(buf, offset+4);              //should == w
     //int height = read4Bytes(buf, offset+8);             //should == 2*h
     //int planesToo = read2Bytes(buf, offset+12);         //should == 1 (does it?)
     int bitCount = read2Bytes(buf, offset+14);
 
     void (*placePixel)(const int pixelNo, const unsigned char* buf,
         const int xorOffset, int& x, int y, const int w,
         SkBitmap* bm, int alphaByte, int m, int shift, SkPMColor* colors) = NULL;
     switch (bitCount)
@@ skipping 235 matching lines @@
 static SkTRegistry<SkImageDecoder*, SkStream*> gReg(sk_libico_dfactory);
 
 static SkImageDecoder::Format get_format_ico(SkStream* stream) {
     if (is_ico(stream)) {
         return SkImageDecoder::kICO_Format;
     }
     return SkImageDecoder::kUnknown_Format;
 }
 
 static SkTRegistry<SkImageDecoder::Format, SkStream*> gFormatReg(get_format_ico);