Verify the full size returned by PIEX

src/codec/SkRawCodec.cpp

 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkCodec.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 497 matching lines @@
         fIsXtransImage = fIsScalable ? (cfaPatternSize.v == 6 && cfaPatternSize.h == 6) : false;
     }
 
     bool initFromPiex() {
         // Does not take the ownership of rawStream.
         SkPiexStream piexStream(fStream.get());
         ::piex::PreviewImageData imageData;
         if (::piex::IsRaw(&piexStream)
             && ::piex::GetPreviewImageData(&piexStream, &imageData) == ::piex::Error::kOk)
         {
+            // Verify the size information, as it is only optional information for PIEX.
+            if (imageData.full_width == 0 || imageData.full_height == 0) {
+                return false;
+            }
+
             dng_point cfaPatternSize(imageData.cfa_pattern_dim[1], imageData.cfa_pattern_dim[0]);
             this->init(static_cast<int>(imageData.full_width),
                        static_cast<int>(imageData.full_height), cfaPatternSize);
             return true;
         }
         return false;
     }
 
     bool readDng() {
         try {
@@ skipping 135 matching lines @@
         }
 
         swizzler->swizzle(dstRow, &srcRow[0]);
         dstRow = SkTAddOffset<void>(dstRow, dstRowBytes);
     }
     return kSuccess;
 }
 
 SkISize SkRawCodec::onGetScaledDimensions(float desiredScale) const {
     SkASSERT(desiredScale <= 1.f);
+
     const SkISize dim = this->getInfo().dimensions();
+    SkASSERT(dim.fWidth != 0 && dim.fHeight != 0);
+
     if (!fDngImage->isScalable()) {
         return dim;
     }
 
     // Limits the minimum size to be 80 on the short edge.
     const float shortEdge = static_cast<float>(SkTMin(dim.fWidth, dim.fHeight));
     if (desiredScale < 80.f / shortEdge) {
         desiredScale = 80.f / shortEdge;
     }
 
@@ skipping 17 matching lines @@
     SkISize sizeFloor = this->onGetScaledDimensions(1.f / std::floor(fullShortEdge / shortEdge));
     SkISize sizeCeil = this->onGetScaledDimensions(1.f / std::ceil(fullShortEdge / shortEdge));
     return sizeFloor == dim || sizeCeil == dim;
 }
 
 SkRawCodec::~SkRawCodec() {}
 
 SkRawCodec::SkRawCodec(SkDngImage* dngImage)
     : INHERITED(dngImage->getImageInfo(), nullptr)
     , fDngImage(dngImage) {}