Merge to M47: Fix extraction of colour components in CPDF_DIBSource::DownSampleScanline32Bit

core/src/fpdfapi/fpdf_render/fpdf_render_loadimage_embeddertest.cpp

Index: core/src/fpdfapi/fpdf_render/fpdf_render_loadimage_embeddertest.cpp
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage_embeddertest.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage_embeddertest.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..1633249d0d33e09ddbbf923e7a8015f39f347788
--- /dev/null
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage_embeddertest.cpp
@@ -0,0 +1,19 @@
+// Copyright 2015 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "testing/embedder_test.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+class FPDFRenderLoadImageEmbeddertest : public EmbedderTest {};
+
+TEST_F(FPDFRenderLoadImageEmbeddertest, Bug_554151) {
+  // Test scanline downsampling with a BitsPerComponent of 4.
+  // Should not crash.
+  EXPECT_TRUE(OpenDocument("bug_554151.pdf"));
+  FPDF_PAGE page = LoadPage(0);
+  EXPECT_NE(nullptr, page);
+  FPDF_BITMAP bitmap = RenderPage(page);
+  FPDFBitmap_Destroy(bitmap);
+  UnloadPage(page);
+}