Fixes for piping bitmaps with encoded data.

src/core/SkOrderedReadBuffer.cpp

 
 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
+#include "SkErrorInternals.h"
 #include "SkOrderedReadBuffer.h"
 #include "SkStream.h"
 #include "SkTypeface.h"
 
 SkOrderedReadBuffer::SkOrderedReadBuffer() : INHERITED() {
     fMemoryPtr = NULL;
 
     fBitmapStorage = NULL;
     fTFArray = NULL;
     fTFCount = 0;
@@ skipping 141 matching lines @@
     const uint32_t byteLength = count * sizeof(SkScalar);
     memcpy(values, fReader.skip(SkAlign4(byteLength)), byteLength);
     return count;
 }
 
 uint32_t SkOrderedReadBuffer::getArrayCount() {
     return *(uint32_t*)fReader.peek();
 }
 
 void SkOrderedReadBuffer::readBitmap(SkBitmap* bitmap) {
+    const int width = this->readInt();
+    const int height = this->readInt();
     const size_t length = this->readUInt();
     if (length > 0) {
         // Bitmap was encoded.
         const void* data = this->skip(length);
-        const int width = this->readInt();
-        const int height = this->readInt();
         if (fBitmapDecoder != NULL && fBitmapDecoder(data, length, bitmap)) {
             SkASSERT(bitmap->width() == width && bitmap->height() == height);
-        } else {
-            // This bitmap was encoded when written, but we are unable to decode, possibly due to
-            // not having a decoder. Use a placeholder bitmap.
-            SkDebugf("Could not decode bitmap. Resulting bitmap will be red.\n");
-            bitmap->setConfig(SkBitmap::kARGB_8888_Config, width, height);
-            bitmap->allocPixels();
-            bitmap->eraseColor(SK_ColorRED);
+            return;
         }
+        // This bitmap was encoded when written, but we are unable to decode, possibly due to
+        // not having a decoder.
+        SkDebugf("Could not decode bitmap. Resulting bitmap will be red.\n");
     } else {
-        if (fBitmapStorage) {
+        // The writer stored a boolean value to determine whether an SkBitmapHeap was used during
+        // writing.
+        if (this->readBool()) {
             const uint32_t index = fReader.readU32();
             fReader.readU32(); // bitmap generation ID (see SkOrderedWriteBuffer::writeBitmap)
-            *bitmap = *fBitmapStorage->getBitmap(index);
-            fBitmapStorage->releaseRef(index);
+            if (fBitmapStorage) {
+                *bitmap = *fBitmapStorage->getBitmap(index);
+                fBitmapStorage->releaseRef(index);
+                return;
+            } else {
+                // Throw an error.
+                SkErrorInternals::SetError(kParseError_SkError, "SkOrderedWriteBuffer::writeBitmap "
+                                           "stored the SkBitmap in an SkBitmapHeap, but "
+                                           "SkOrderedReadBuffer has no SkBitmapHeapReader to "
+                                           "retrieve the SkBitmap.");
+            }
         } else {
+            // The SkBitmap was simply flattened.
             bitmap->unflatten(*this);
+            return;
         }
     }
+    // Could not read the SkBitmap. Use a placeholder bitmap.
+    bitmap->setConfig(SkBitmap::kARGB_8888_Config, width, height);
+    bitmap->allocPixels();
+    bitmap->eraseColor(SK_ColorRED);
 }
 
 SkTypeface* SkOrderedReadBuffer::readTypeface() {
 
     uint32_t index = fReader.readU32();
     if (0 == index || index > (unsigned)fTFCount) {
         if (index) {
             SkDebugf("====== typeface index %d\n", index);
         }
         return NULL;
@@ skipping 40 matching lines @@
         if (sizeRecorded != sizeRead) {
             // we could try to fix up the offset...
             sk_throw();
         }
     } else {
         // we must skip the remaining data
         fReader.skip(sizeRecorded);
     }
     return obj;
 }