Implementing filling for SkBmpCodec

The bmp codec currently returns kIncompleteInput
when the stream is truncated, which we treat as a
partial success.  However, we neglect the fill the
remaining pixels in the image, leaving these
uninitialized.

This CL addresses this problem by initializing the
remaining pixels in the image to default values.

BUG=skia:3257

Review URL: https://codereview.chromium.org/1075243003

1 files changed, 17 insertions, 12 deletions

diff --git a/tests/SwizzlerTest.cpp b/tests/SwizzlerTest.cpp
index f02f86b682..147dfaa83d 100644
--- a/tests/SwizzlerTest.cpp
+++ b/tests/SwizzlerTest.cpp
@@ -15,6 +15,7 @@ static const uint32_t kFillColor = 0x22334455;
 static void check_fill(skiatest::Reporter* r,
                        const SkImageInfo& imageInfo,
                        uint32_t startRow,
+                       uint32_t endRow,
                        size_t rowBytes,
                        uint32_t offset,
                        uint32_t colorOrIndex,
@@ -32,15 +33,17 @@ static void check_fill(skiatest::Reporter* r,
     memset(storage.get(), 0, totalBytes);
     // Adjust the pointer in order to test on different memory alignments
     uint8_t* imageData = storage.get() + offset;
+    uint8_t* imageStart = imageData + rowBytes * startRow;
 
     // Fill image with the fill value starting at the indicated row
-    SkSwizzler::Fill(imageData, imageInfo, rowBytes, startRow, colorOrIndex, colorTable);
+    SkSwizzler::Fill(imageStart, imageInfo, rowBytes, endRow - startRow + 1, colorOrIndex,
+            colorTable);
 
     // Ensure that the pixels are filled properly
     // The bots should catch any memory corruption
     uint8_t* indexPtr = imageData + startRow * rowBytes;
     uint32_t* colorPtr = (uint32_t*) indexPtr;
-    for (int32_t y = startRow; y < imageInfo.height(); y++) {
+    for (uint32_t y = startRow; y <= endRow; y++) {
         for (int32_t x = 0; x < imageInfo.width(); x++) {
             if (kIndex_8_SkColorType == imageInfo.colorType()) {
                 REPORTER_ASSERT(r, kFillIndex == indexPtr[x]);
@@ -90,20 +93,22 @@ DEF_TEST(SwizzlerFill, r) {
                 // If there is padding, we can invent an offset to change the memory alignment
                 for (uint32_t offset = 0; offset <= padding; offset++) {
 
-                    // Test all possible start rows
+                    // Test all possible start rows with all possible end rows
                     for (uint32_t startRow = 0; startRow < height; startRow++) {
+                        for (uint32_t endRow = startRow; endRow < height; endRow++) {
 
-                        // Fill with an index that we use to look up a color
-                        check_fill(r, colorInfo, startRow, colorRowBytes, offset, kFillIndex,
-                               colorTable);
+                            // Fill with an index that we use to look up a color
+                            check_fill(r, colorInfo, startRow, endRow, colorRowBytes, offset,
+                                    kFillIndex, colorTable);
 
-                        // Fill with a color
-                        check_fill(r, colorInfo, startRow, colorRowBytes, offset, kFillColor,
-                                NULL);
+                            // Fill with a color
+                            check_fill(r, colorInfo, startRow, endRow, colorRowBytes, offset,
+                                    kFillColor, NULL);
 
-                        // Fill with an index
-                        check_fill(r, indexInfo, startRow, indexRowBytes, offset, kFillIndex,
-                                NULL);
+                            // Fill with an index
+                            check_fill(r, indexInfo, startRow, endRow, indexRowBytes, offset,
+                                    kFillIndex, NULL);
+                        }
                     }
                 }
             }