Fix bmp RLE "bug" and add invalid image test to CodexTest

tests/CodexTest.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 "Resources.h"
 #include "SkBitmap.h"
 #include "SkCodec.h"
@@ skipping 248 matching lines @@
 // Ensure that onGetScaledDimensions returns valid image dimensions to use for decodes
 DEF_TEST(Codec_Dimensions, r) {
     // JPG
     test_dimensions(r, "CMYK.jpg");
     test_dimensions(r, "color_wheel.jpg");
     test_dimensions(r, "grayscale.jpg");
     test_dimensions(r, "mandrill_512_q075.jpg");
     test_dimensions(r, "randPixels.jpg");
 }
 
-static void test_empty(skiatest::Reporter* r, const char path[]) {
+static void test_invalid(skiatest::Reporter* r, const char path[]) {
     SkAutoTDelete<SkStream> stream(resource(path));
     if (!stream) {
         SkDebugf("Missing resource '%s'\n", path);
         return;
     }
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromStream(stream.detach()));
     REPORTER_ASSERT(r, NULL == codec);
 }
 
 DEF_TEST(Codec_Empty, r) {
     // Test images that should not be able to create a codec
-    test_empty(r, "empty_images/zero-dims.gif");
-    test_empty(r, "empty_images/zero-embedded.ico");
-    test_empty(r, "empty_images/zero-width.bmp");
-    test_empty(r, "empty_images/zero-height.bmp");
-    test_empty(r, "empty_images/zero-width.jpg");
-    test_empty(r, "empty_images/zero-height.jpg");
-    test_empty(r, "empty_images/zero-width.png");
-    test_empty(r, "empty_images/zero-height.png");
-    test_empty(r, "empty_images/zero-width.wbmp");
-    test_empty(r, "empty_images/zero-height.wbmp");
+    test_invalid(r, "empty_images/zero-dims.gif");
+    test_invalid(r, "empty_images/zero-embedded.ico");
+    test_invalid(r, "empty_images/zero-width.bmp");
+    test_invalid(r, "empty_images/zero-height.bmp");
+    test_invalid(r, "empty_images/zero-width.jpg");
+    test_invalid(r, "empty_images/zero-height.jpg");
+    test_invalid(r, "empty_images/zero-width.png");
+    test_invalid(r, "empty_images/zero-height.png");
+    test_invalid(r, "empty_images/zero-width.wbmp");
+    test_invalid(r, "empty_images/zero-height.wbmp");
+    // This image is an ico with an embedded mask-bmp.  This is illegal.
+    test_invalid(r, "invalid_images/mask-bmp-ico.ico");
 }
 
 static void test_invalid_parameters(skiatest::Reporter* r, const char path[]) {
     SkAutoTDelete<SkStream> stream(resource(path));
     if (!stream) {
         SkDebugf("Missing resource '%s'\n", path);
         return;
     }
     SkAutoTDelete<SkScanlineDecoder> decoder(SkScanlineDecoder::NewFromStream(
         stream.detach()));
@@ skipping 16 matching lines @@
     REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
     result = decoder->start(
         decoder->getInfo().makeColorType(kIndex_8_SkColorType));
     REPORTER_ASSERT(r, SkCodec::kInvalidParameters == result);
 }
 
 DEF_TEST(Codec_Params, r) {
     test_invalid_parameters(r, "index8.png");
     test_invalid_parameters(r, "mandrill.wbmp");
 }