Implementing filling for SkBmpCodec

src/codec/SkCodec_libbmp.cpp

Index: src/codec/SkCodec_libbmp.cpp
diff --git a/src/codec/SkCodec_libbmp.cpp b/src/codec/SkCodec_libbmp.cpp
index b553deae6f8c0b14f669d19ee76aa4f8536f19d4..0ca15be5b54749cfb82adb0f3eeb20c728bf8cb8 100644
--- a/src/codec/SkCodec_libbmp.cpp
+++ b/src/codec/SkCodec_libbmp.cpp
@@ -701,6 +701,9 @@ SkCodec::Result SkBmpCodec::onGetPixels(const SkImageInfo& dstInfo,
         for (; i < maxColors; i++) {
             colorTable[i] = SkPackARGB32NoCheck(0xFF, 0, 0, 0);
         }
+
+        // Set the color table
+        fColorTable.reset(SkNEW_ARGS(SkColorTable, (colorTable, maxColors)));
     }
 
     // Bmp-in-Ico files do not use an offset to indicate where the pixel data
@@ -724,8 +727,7 @@ SkCodec::Result SkBmpCodec::onGetPixels(const SkImageInfo& dstInfo,
         }
     }
 
-    // Set the color table and return true on success
-    fColorTable.reset(SkNEW_ARGS(SkColorTable, (colorTable, maxColors)));
+    // Return true on success
     return true;
 }
 
@@ -757,6 +759,12 @@ SkCodec::Result SkBmpCodec::decodeMask(const SkImageInfo& dstInfo,
         // Read a row of the input
         if (stream()->read(srcRow, rowBytes) != rowBytes) {
             SkCodecPrintf("Warning: incomplete input stream.\n");
+            // Fill the destination image on failure
+            // By using zero as the fill value, we will fill with transparent
+            // pixels for non-opaque images and white for opaque images.
+            // These are arbitrary choices but allow for consistent behavior.
+            SkSwizzler::Fill(dst, dstInfo, dstRowBytes, y, 0, NULL,
+                    fRowOrder == kBottomUp_RowOrder);
             return kIncompleteInput;
         }
 
@@ -1096,9 +1104,12 @@ SkCodec::Result SkBmpCodec::decode(const SkImageInfo& dstInfo,
             return kInvalidInput;
     }
 
+    // Get a pointer to the color table if it exists
+    const SkPMColor* colorPtr = NULL != fColorTable.get() ? fColorTable->readColors() : NULL;
+
     // Create swizzler
     SkAutoTDelete<SkSwizzler> swizzler(SkSwizzler::CreateSwizzler(config,
-            fColorTable->readColors(), dstInfo, dst, dstRowBytes,
+            colorPtr, dstInfo, dst, dstRowBytes,
             SkImageGenerator::kNo_ZeroInitialized));
 
     // Allocate space for a row buffer and a source for the swizzler
@@ -1110,6 +1121,13 @@ SkCodec::Result SkBmpCodec::decode(const SkImageInfo& dstInfo,
         // Read a row of the input
         if (stream()->read(srcBuffer.get(), rowBytes) != rowBytes) {
             SkCodecPrintf("Warning: incomplete input stream.\n");
+            // Fill the destination image on failure
+            // By using zero as the fill value, we will fill with the first
+            // color in the color table for palette images, transparent
+            // pixels for non-opaque images, and white for opaque images.
+            // These are arbitrary choices but allow for consistent behavior.
+            SkSwizzler::Fill(dst, dstInfo, dstRowBytes, y, 0, colorPtr,
+                    fRowOrder == kBottomUp_RowOrder);
             return kIncompleteInput;
         }