Fix rewinding bug in SkJpegCodec

tests/CodecTest.cpp

Index: tests/CodecTest.cpp
diff --git a/tests/CodecTest.cpp b/tests/CodecTest.cpp
index 12d6ac8d3d2997a164da8219a4bd39f7923e349b..b8b957fe55cf7f6dca6640ac334ca2870a3c0b89 100644
--- a/tests/CodecTest.cpp
+++ b/tests/CodecTest.cpp
@@ -1012,3 +1012,32 @@ 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);
+}