Fix rewinding bug in SkJpegCodec (cherry picked from Skia)

am: 63a53c1e4b

Change-Id: I44e6f3c9a988844a90d5f8be0c19e6c4e7cd585a

2 files changed, 35 insertions, 5 deletions

diff --git a/src/codec/SkJpegCodec.cpp b/src/codec/SkJpegCodec.cpp
index d36051511c..77ad5ddb72 100644
--- a/src/codec/SkJpegCodec.cpp
+++ b/src/codec/SkJpegCodec.cpp
@@ -80,6 +80,7 @@ SkJpegCodec::SkJpegCodec(const SkImageInfo& srcInfo, SkStream* stream,
     : INHERITED(srcInfo, stream)
     , fDecoderMgr(decoderMgr)
     , fReadyState(decoderMgr->dinfo()->global_state)
+    , fSrcRow(nullptr)
     , fSwizzlerSubset(SkIRect::MakeEmpty())
 {}
 
@@ -155,6 +156,11 @@ bool SkJpegCodec::onRewind() {
     }
     SkASSERT(nullptr != decoderMgr);
     fDecoderMgr.reset(decoderMgr);
+
+    fSwizzler.reset(nullptr);
+    fSrcRow = nullptr;
+    fStorage.free();
+
     return true;
 }
 
@@ -410,11 +416,6 @@ SkCodec::Result SkJpegCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
         return kInvalidConversion;
     }
 
-    // Remove objects used for sampling.
-    fSwizzler.reset(nullptr);
-    fSrcRow = nullptr;
-    fStorage.free();
-
     // Now, given valid output dimensions, we can start the decompress
     if (!jpeg_start_decompress(fDecoderMgr->dinfo())) {
         SkCodecPrintf("start decompress failed\n");
diff --git a/tests/CodexTest.cpp b/tests/CodexTest.cpp
index 51e41235cb..8ce63029a6 100644
--- a/tests/CodexTest.cpp
+++ b/tests/CodexTest.cpp
@@ -971,3 +971,32 @@ DEF_TEST(Codec_wbmp_max_size, r) {
 
     REPORTER_ASSERT(r, !codec);
 }
+
+DEF_TEST(Codec_jpeg_rewind, r) {
+    const char* path = "mandrill_512_q075.jpg";
+    SkAutoTDelete<SkStream> stream(resource(path));
+    if (!stream) {
+        SkDebugf("Missing resource '%s'\n", path);
+        return;
+    }
+    SkAutoTDelete<SkAndroidCodec> codec(SkAndroidCodec::NewFromStream(stream.release()));
+    if (!codec) {
+        ERRORF(r, "Unable to create codec '%s'.", path);
+        return;
+    }
+
+    const int width = codec->getInfo().width();
+    const int height = codec->getInfo().height();
+    size_t rowBytes = sizeof(SkPMColor) * width;
+    SkAutoMalloc pixelStorage(height * rowBytes);
+
+    // Perform a sampled decode.
+    SkAndroidCodec::AndroidOptions opts;
+    opts.fSampleSize = 12;
+    codec->getAndroidPixels(codec->getInfo().makeWH(width / 12, height / 12), pixelStorage.get(),
+                            rowBytes, &opts);
+
+    // Rewind the codec and perform a full image decode.
+    SkCodec::Result result = codec->getPixels(codec->getInfo(), pixelStorage.get(), rowBytes);
+    REPORTER_ASSERT(r, SkCodec::kSuccess == result);
+}