Call rewindIfNeeded in SkCodec

src/codec/SkCodec.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 "SkBmpCodec.h"
 #include "SkCodec.h"
 #include "SkData.h"
@@ skipping 69 matching lines @@
     , fStream(stream)
     , fNeedsRewind(false)
     , fDstInfo()
     , fOptions()
     , fCurrScanline(-1)
 {}
 
 SkCodec::~SkCodec() {}
 
 bool SkCodec::rewindIfNeeded() {
+    if (!fStream) {
+        // Some codecs do not have a stream, but they hold others that do. They
+        // must handle rewinding themselves.
+        return true;
+    }
+
     // Store the value of fNeedsRewind so we can update it. Next read will
     // require a rewind.
     const bool needsRewind = fNeedsRewind;
     fNeedsRewind = true;
     if (!needsRewind) {
         return true;
     }
 
     // startScanlineDecode will need to be called before decoding scanlines.
     fCurrScanline = -1;
@@ skipping 31 matching lines @@
 
     {
         SkAlphaType canonical;
         if (!SkColorTypeValidateAlphaType(info.colorType(), info.alphaType(), &canonical)
             || canonical != info.alphaType())
         {
             return kInvalidConversion;
         }
     }
 
+    if (!this->rewindIfNeeded()) {
+        return kCouldNotRewind;
+    }
+
     // Default options.
     Options optsStorage;
     if (nullptr == options) {
         options = &optsStorage;
     }
     const Result result = this->onGetPixels(info, pixels, rowBytes, *options, ctable, ctableCount);
 
     if ((kIncompleteInput == result || kSuccess == result) && ctableCount) {
         SkASSERT(*ctableCount >= 0 && *ctableCount <= 256);
     }
@@ skipping 14 matching lines @@
             return SkCodec::kInvalidParameters;
         }
     } else {
         if (ctableCount) {
             *ctableCount = 0;
         }
         ctableCount = nullptr;
         ctable = nullptr;
     }
 
+    if (!this->rewindIfNeeded()) {
+        return kCouldNotRewind;
+    }
+
     // Set options.
     Options optsStorage;
     if (nullptr == options) {
         options = &optsStorage;
     }
 
     const Result result = this->onStartScanlineDecode(dstInfo, *options, ctable, ctableCount);
     if (result != SkCodec::kSuccess) {
         return result;
     }
@@ skipping 34 matching lines @@
         // Arguably, we could just skip the scanlines which are remaining,
         // and return kSuccess. We choose to return invalid so the client
         // can catch their bug.
         return SkCodec::kInvalidParameters;
     }
 
     const Result result = this->onSkipScanlines(countLines);
     fCurrScanline += countLines;
     return result;
 }