ensure that opaque-only colortypes always report opaque-alphatype

src/core/SkBitmap.cpp

Index: src/core/SkBitmap.cpp
diff --git a/src/core/SkBitmap.cpp b/src/core/SkBitmap.cpp
index 3418fad7f197e1014fe63243a1571ee083178363..951bb6fe9883ba8d02ea7fb921c2e900e0b4d556 100644
--- a/src/core/SkBitmap.cpp
+++ b/src/core/SkBitmap.cpp
@@ -253,7 +253,14 @@ static bool validate_alphaType(SkColorType colorType, SkAlphaType alphaType,
     return true;
 }
 
-bool SkBitmap::setConfig(const SkImageInfo& info, size_t rowBytes) {
+bool SkBitmap::setConfig(const SkImageInfo& origInfo, size_t rowBytes) {
+    SkImageInfo info = origInfo;
+
+    if (!validate_alphaType(info.fColorType, info.fAlphaType,
+                            &info.fAlphaType)) {
+        return reset_return_false(this);
+    }
+    
     // require that rowBytes fit in 31bits
     int64_t mrb = info.minRowBytes64();
     if ((int32_t)mrb != mrb) {
@@ -1619,6 +1626,13 @@ SkBitmap::RLEPixels::~RLEPixels() {
 #ifdef SK_DEBUG
 void SkBitmap::validate() const {
     fInfo.validate();
+
+    // ImageInfo may not require this, but Bitmap ensures that opaque-only
+    // colorTypes report opaque for their alphatype
+    if (kRGB_565_SkColorType == fInfo.colorType()) {
+        SkASSERT(kOpaque_SkAlphaType == fInfo.alphaType());
+    }
+
     SkASSERT(fInfo.validRowBytes(fRowBytes));
     uint8_t allFlags = kImageIsOpaque_Flag | kImageIsVolatile_Flag | kImageIsImmutable_Flag;
 #ifdef SK_BUILD_FOR_ANDROID