Fill incomplete images in SkCodec parent class

src/codec/SkBmpMaskCodec.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBmpMaskCodec.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 11 matching lines @@
     , fSrcBuffer(new uint8_t [fSrcRowBytes])
 {}
 
 /*
  * Initiates the bitmap decode
  */
 SkCodec::Result SkBmpMaskCodec::onGetPixels(const SkImageInfo& dstInfo,
                                             void* dst, size_t dstRowBytes,
                                             const Options& opts,
                                             SkPMColor* inputColorPtr,
-                                            int* inputColorCount) {
+                                            int* inputColorCount,
+                                            int* rowsDecoded) {
     if (opts.fSubset) {
         // Subsets are not supported.
         return kUnimplemented;
     }
     if (dstInfo.dimensions() != this->getInfo().dimensions()) {
         SkCodecPrintf("Error: scaling not supported.\n");
         return kInvalidScale;
     }
 
     if (!conversion_possible(dstInfo, this->getInfo())) {
         SkCodecPrintf("Error: cannot convert input type to output type.\n");
         return kInvalidConversion;
     }
 
     Result result = this->prepareToDecode(dstInfo, opts, inputColorPtr, inputColorCount);
     if (kSuccess != result) {
         return result;
     }
 
-    return this->decodeRows(dstInfo, dst, dstRowBytes, opts);
+    uint32_t rows = this->decodeRows(dstInfo, dst, dstRowBytes, opts);
+    if (rows != dstInfo.height()) {
+        *rowsDecoded = rows;
+        return kIncompleteInput;
+    }
+    return kSuccess;
 }
 
 bool SkBmpMaskCodec::initializeSwizzler(const SkImageInfo& dstInfo) {
     // Create the swizzler
     fMaskSwizzler.reset(SkMaskSwizzler::CreateMaskSwizzler(
             dstInfo, this->getInfo(), fMasks, this->bitsPerPixel()));
 
     if (nullptr == fMaskSwizzler.get()) {
         return false;
     }
 
     return true;
 }
 
 SkCodec::Result SkBmpMaskCodec::prepareToDecode(const SkImageInfo& dstInfo,
         const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
     // Initialize a the mask swizzler
     if (!this->initializeSwizzler(dstInfo)) {
         SkCodecPrintf("Error: cannot initialize swizzler.\n");
         return SkCodec::kInvalidConversion;
     }
 
     return SkCodec::kSuccess;
 }
 
 /*
  * Performs the decoding
  */
-SkCodec::Result SkBmpMaskCodec::decodeRows(const SkImageInfo& dstInfo,
+int SkBmpMaskCodec::decodeRows(const SkImageInfo& dstInfo,
                                            void* dst, size_t dstRowBytes,
                                            const Options& opts) {
     // Iterate over rows of the image
     uint8_t* srcRow = fSrcBuffer.get();
     const int height = dstInfo.height();
     for (int y = 0; y < height; y++) {
         // Read a row of the input
         if (this->stream()->read(srcRow, fSrcRowBytes) != fSrcRowBytes) {
             SkCodecPrintf("Warning: incomplete input stream.\n");
-            // Fill the destination image on failure
-            void* dstStart = this->getDstStartRow(dst, dstRowBytes, y);
-            uint32_t fillColor = get_fill_color_or_index(dstInfo.alphaType());
-            SkSwizzler::Fill(dstStart, dstInfo, dstRowBytes, height - y,
-                    fillColor, nullptr, opts.fZeroInitialized);
-            return kIncompleteInput;
+            return y;
         }
 
         // Decode the row in destination format
         uint32_t row = this->getDstRow(y, height);
         void* dstRow = SkTAddOffset<void>(dst, row * dstRowBytes);
         fMaskSwizzler->swizzle(dstRow, srcRow);
     }
 
     // Finished decoding the entire image
-    return kSuccess;
+    return height;
 }