Fix issue in image decoders where the bitmap config was not properly set.

src/images/SkImageDecoder_libpng.cpp

 
 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "SkImageDecoder.h"
@@ skipping 315 matching lines @@
     SkPMColor           theTranspColor = 0; // 0 tells us not to try to match
 
     if (!this->getBitmapConfig(png_ptr, info_ptr, &config, &hasAlpha, &theTranspColor)) {
         return false;
     }
 
     const int sampleSize = this->getSampleSize();
     SkScaledBitmapSampler sampler(origWidth, origHeight, sampleSize);
     decodedBitmap->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight());
 
+    // we should communicate alphaType, even if we early-return in bounds-only-mode.
+    if (this->getRequireUnpremultipliedColors()) {
+        decodedBitmap->setAlphaType(kUnpremul_SkAlphaType);
+    }
+
     if (SkImageDecoder::kDecodeBounds_Mode == mode) {
         return true;
     }
 
     // from here down we are concerned with colortables and pixels
 
     // we track if we actually see a non-opaque pixels, since sometimes a PNG sets its colortype
     // to |= PNG_COLOR_MASK_ALPHA, but all of its pixels are in fact opaque. We care, since we
     // draw lots faster if we can flag the bitmap has being opaque
     bool reallyHasAlpha = false;
@@ skipping 125 matching lines @@
                 return false;
             default: {
                 // Fall through to finish the decode. This config either
                 // supports unpremul or it is irrelevant because it has no
                 // alpha (or only alpha).
                 // These brackets prevent a warning.
             }
         }
     }
 
-    SkAlphaType alphaType = kOpaque_SkAlphaType;
-    if (reallyHasAlpha) {
-        if (this->getRequireUnpremultipliedColors()) {
-            alphaType = kUnpremul_SkAlphaType;
-        } else {
-            alphaType = kPremul_SkAlphaType;
-        }
+    if (!reallyHasAlpha) {
+        decodedBitmap->setAlphaType(kOpaque_SkAlphaType);
     }
-    decodedBitmap->setAlphaType(alphaType);
     return true;
 }
 
 
 
 bool SkPNGImageDecoder::getBitmapConfig(png_structp png_ptr, png_infop info_ptr,
                                         SkBitmap::Config* SK_RESTRICT configp,
                                         bool* SK_RESTRICT hasAlphap,
                                         SkPMColor* SK_RESTRICT theTranspColorp) {
     png_uint_32 origWidth, origHeight;
@@ skipping 788 matching lines @@
     return SkImageDecoder::kUnknown_Format;
 }
 
 SkImageEncoder* sk_libpng_efactory(SkImageEncoder::Type t) {
     return (SkImageEncoder::kPNG_Type == t) ? SkNEW(SkPNGImageEncoder) : NULL;
 }
 
 static SkImageDecoder_DecodeReg gDReg(sk_libpng_dfactory);
 static SkImageDecoder_FormatReg gFormatReg(get_format_png);
 static SkImageEncoder_EncodeReg gEReg(sk_libpng_efactory);