Fix colorType/alphaType checks in SkCodec

src/codec/SkBmpStandardCodec.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 "SkBmpStandardCodec.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 134 matching lines @@
         if (stream()->skip(fOffset - colorBytes) != fOffset - colorBytes) {
             SkCodecPrintf("Error: unable to skip to image data.\n");
             return false;
         }
     }
 
     // Return true on success
     return true;
 }
 
-bool SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts) {
+void SkBmpStandardCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& opts) {
     // Get swizzler configuration
-    SkSwizzler::SrcConfig config;
+    SkSwizzler::SrcConfig config = SkSwizzler::kUnknown;
     switch (this->bitsPerPixel()) {
         case 1:
             config = SkSwizzler::kIndex1;
             break;
         case 2:
             config = SkSwizzler::kIndex2;
             break;
         case 4:
             config = SkSwizzler::kIndex4;
             break;
         case 8:
             config = SkSwizzler::kIndex;
             break;
         case 24:
             config = SkSwizzler::kBGR;
             break;
         case 32:
             if (kOpaque_SkAlphaType == this->getInfo().alphaType()) {
                 config = SkSwizzler::kBGRX;
             } else {
                 config = SkSwizzler::kBGRA;
             }
             break;
         default:
             SkASSERT(false);
-            return false;
     }
 
     // Get a pointer to the color table if it exists
     const SkPMColor* colorPtr = get_color_ptr(fColorTable.get());
 
     // Create swizzler
     fSwizzler.reset(SkSwizzler::CreateSwizzler(config, colorPtr, dstInfo, opts));
-
-    if (nullptr == fSwizzler.get()) {
-        return false;
-    }
-    return true;
+    SkASSERT(fSwizzler);
 }
 
 SkCodec::Result SkBmpStandardCodec::prepareToDecode(const SkImageInfo& dstInfo,
         const SkCodec::Options& options, SkPMColor inputColorPtr[], int* inputColorCount) {
     // Create the color table if necessary and prepare the stream for decode
     // Note that if it is non-NULL, inputColorCount will be modified
     if (!this->createColorTable(dstInfo.alphaType(), inputColorCount)) {
         SkCodecPrintf("Error: could not create color table.\n");
         return SkCodec::kInvalidInput;
     }
 
     // Copy the color table to the client if necessary
     copy_color_table(dstInfo, this->fColorTable, inputColorPtr, inputColorCount);
 
-    // Initialize a swizzler if necessary
-    if (!this->initializeSwizzler(dstInfo, options)) {
-        SkCodecPrintf("Error: cannot initialize swizzler.\n");
-        return SkCodec::kInvalidConversion;
-    }
+    // Initialize a swizzler
+    this->initializeSwizzler(dstInfo, options);
     return SkCodec::kSuccess;
 }
 
 /*
  * Performs the bitmap decoding for standard input format
  */
 int SkBmpStandardCodec::decodeRows(const SkImageInfo& dstInfo, void* dst, size_t dstRowBytes,
         const Options& opts) {
     // Iterate over rows of the image
     const int height = dstInfo.height();
@@ skipping 102 matching lines @@
     }
 }
 
 uint32_t SkBmpStandardCodec::onGetFillValue(SkColorType colorType) const {
     const SkPMColor* colorPtr = get_color_ptr(fColorTable.get());
     if (colorPtr) {
         return get_color_table_fill_value(colorType, colorPtr, 0);
     }
     return INHERITED::onGetFillValue(colorType);
 }