Remove png_read_end from SkPngScanlineDecoder

src/codec/SkCodec_libpng.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 "SkCodec_libpng.h"
 #include "SkCodecPriv.h"
 #include "SkColorPriv.h"
@@ skipping 583 matching lines @@
 public:
     SkPngScanlineDecoder(const SkImageInfo& dstInfo, SkPngCodec* codec)
         : INHERITED(dstInfo)
         , fCodec(codec)
         , fHasAlpha(false)
     {
         fStorage.reset(dstInfo.width() * SkSwizzler::BytesPerPixel(fCodec->fSrcConfig));
         fSrcRow = static_cast<uint8_t*>(fStorage.get());
     }
 
-    ~SkPngScanlineDecoder() {
-        fCodec->finish();
-    }
+    ~SkPngScanlineDecoder() {}

[scroggo, 2015/07/20 20:07:25]

nit: I think you can remove this line completely, and the compiler will generate
the same destructor.

(I was wrong on this in one of Matt's CLs, so I may be wrong here as well...)

 
     SkCodec::Result onGetScanlines(void* dst, int count, size_t rowBytes) override {
         if (setjmp(png_jmpbuf(fCodec->fPng_ptr))) {
             SkCodecPrintf("setjmp long jump!\n");
             return SkCodec::kInvalidInput;
         }
 
         for (int i = 0; i < count; i++) {
             png_read_rows(fCodec->fPng_ptr, &fSrcRow, png_bytepp_NULL, 1);
             fCodec->fSwizzler->setDstRow(dst);
@@ skipping 38 matching lines @@
         , fCodec(codec)
         , fHasAlpha(false)
         , fCurrentRow(0)
         , fHeight(dstInfo.height())
     {
         fSrcRowBytes = dstInfo.width() * SkSwizzler::BytesPerPixel(fCodec->fSrcConfig);
         fGarbageRow.reset(fSrcRowBytes);
         fGarbageRowPtr = static_cast<uint8_t*>(fGarbageRow.get());
     }
 
-    ~SkPngInterlacedScanlineDecoder() {
-        fCodec->finish();
-    }
+    ~SkPngInterlacedScanlineDecoder() {}

[scroggo, 2015/07/20 20:07:25]

Again, I *think* the compiler will generate the same destructor without this
line.

 
     SkCodec::Result onGetScanlines(void* dst, int count, size_t dstRowBytes) override {
         //rewind stream if have previously called onGetScanlines, 
         //since we need entire progressive image to get scanlines
         if (!fCodec->handleRewind()) {
             return SkCodec::kCouldNotRewind;
         }
         if (setjmp(png_jmpbuf(fCodec->fPng_ptr))) {
             SkCodecPrintf("setjmp long jump!\n");
             return SkCodec::kInvalidInput;
@@ skipping 82 matching lines @@
 
     SkASSERT(codec->fNumberPasses != INVALID_NUMBER_PASSES);
     if (codec->fNumberPasses > 1) {
         // interlaced image
         return SkNEW_ARGS(SkPngInterlacedScanlineDecoder, (dstInfo, codec.detach()));
     }
 
     return SkNEW_ARGS(SkPngScanlineDecoder, (dstInfo, codec.detach()));
 }