Fill incomplete images in SkCodec parent class

src/codec/SkBmpMaskCodec.cpp

Index: src/codec/SkBmpMaskCodec.cpp
diff --git a/src/codec/SkBmpMaskCodec.cpp b/src/codec/SkBmpMaskCodec.cpp
index 3036f337b7f02b21803c70ff6b4ae3895d20edd0..f18507755fd404b6053aaed93f0445d68993149b 100644
--- a/src/codec/SkBmpMaskCodec.cpp
+++ b/src/codec/SkBmpMaskCodec.cpp
@@ -52,7 +52,12 @@ SkCodec::Result SkBmpMaskCodec::onGetPixels(const SkImageInfo& dstInfo,
         return result;
     }
 
-    return this->decodeRows(dstInfo, dst, dstRowBytes, opts);
+    uint32_t rows = this->decodeRows(dstInfo, dst, dstRowBytes, opts);
+    if (rows != dstInfo.height()) {
+        this->setIncompleteScanlines(dstInfo.height() - rows);
+        return kIncompleteInput;
+    }
+    return kSuccess;
 }
 
 bool SkBmpMaskCodec::initializeSwizzler(const SkImageInfo& dstInfo) {
@@ -81,7 +86,7 @@ SkCodec::Result SkBmpMaskCodec::prepareToDecode(const SkImageInfo& dstInfo,
 /*
  * Performs the decoding
  */
-SkCodec::Result SkBmpMaskCodec::decodeRows(const SkImageInfo& dstInfo,
+uint32_t SkBmpMaskCodec::decodeRows(const SkImageInfo& dstInfo,
                                            void* dst, size_t dstRowBytes,
                                            const Options& opts) {
     // Iterate over rows of the image
@@ -91,12 +96,7 @@ SkCodec::Result SkBmpMaskCodec::decodeRows(const SkImageInfo& dstInfo,
         // 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;

[scroggo, 2015/09/22 18:02:48]

It seems like we could have called Fill here, right? Did you not because this is
also used by scanline decoder?

Wait, I think I follow - getPixels takes care of this for us, right?

[msarett, 2015/09/23 13:22:40]

Yes.  It was my intention to make getPixels() take care of filling, so all of
the subcodecs do not need to have similar code.

         }
 
         // Decode the row in destination format
@@ -106,5 +106,5 @@ SkCodec::Result SkBmpMaskCodec::decodeRows(const SkImageInfo& dstInfo,
     }
 
     // Finished decoding the entire image
-    return kSuccess;
+    return height;
 }