Add an assert that we still have a buffer to readFromBuffer().

sk_free(fBuffer.detach()) means fBuffer will be left as NULL, not a zero-length malloc.

BUG=skia:

Review URL: https://codereview.chromium.org/669813002

1 files changed, 2 insertions, 1 deletions

diff --git a/src/utils/SkFrontBufferedStream.cpp b/src/utils/SkFrontBufferedStream.cpp
index 8cb3931082..9a666dcc7e 100644
--- a/src/utils/SkFrontBufferedStream.cpp
+++ b/src/utils/SkFrontBufferedStream.cpp
@@ -119,6 +119,7 @@ size_t FrontBufferedStream::readFromBuffer(char* dst, size_t size) {
 size_t FrontBufferedStream::bufferAndWriteTo(char* dst, size_t size) {
     SkASSERT(size > 0);
     SkASSERT(fOffset >= fBufferedSoFar);
+    SkASSERT(fBuffer);
     // Data needs to be buffered. Buffer up to the lesser of the size requested
     // and the remainder of the max buffer size.
     const size_t bytesToBuffer = SkTMin(size, fBufferSize - fBufferedSoFar);
@@ -148,7 +149,7 @@ size_t FrontBufferedStream::readDirectlyFromStream(char* dst, size_t size) {
     // If we have read past the end of the buffer, rewinding is no longer
     // supported, so we can go ahead and free the memory.
     if (bytesReadDirectly > 0) {
-        fBuffer.reset(0);
+        sk_free(fBuffer.detach());
     }
 
     return bytesReadDirectly;