Treat 0 returned from HttpStream::ReadResponseBody correctly.

net/http/http_response_body_drainer_unittest.cc

Index: net/http/http_response_body_drainer_unittest.cc
diff --git a/net/http/http_response_body_drainer_unittest.cc b/net/http/http_response_body_drainer_unittest.cc
index d9b6492a5378ad55986d89375c2a53894e441bc9..23356abc030eec8d719e4bffa5f17b9d79366d3e 100644
--- a/net/http/http_response_body_drainer_unittest.cc
+++ b/net/http/http_response_body_drainer_unittest.cc
@@ -69,6 +69,7 @@ class MockHttpStream : public HttpStream {
         closed_(false),
         stall_reads_forever_(false),
         num_chunks_(0),
+        delay_eof_chunk_(false),
         is_complete_(false),
         ALLOW_THIS_IN_INITIALIZER_LIST(weak_factory_(this)) {}
   virtual ~MockHttpStream() {}
@@ -130,6 +131,8 @@ class MockHttpStream : public HttpStream {
 
   void set_num_chunks(int num_chunks) { num_chunks_ = num_chunks; }
 
+  void DelayEofChunk() { delay_eof_chunk_ = true; }

[mmenke, 2012/10/12 18:55:05]

Think the logic would be a little simpler if you made this
"is_final_chunk_zero_bytes_" and changed behavior accordingly.  Then the program
flow would be a bit more consistent in both cases.

Note that for unknown reasons, the final chunk is read synchronously, so you'd
currently need to put the code in the fall through case (where "return buf_len;"
is).

+
  private:
   void CompleteRead();
 
@@ -141,6 +144,7 @@ class MockHttpStream : public HttpStream {
   bool closed_;
   bool stall_reads_forever_;
   int num_chunks_;
+  bool delay_eof_chunk_;
   bool is_complete_;
   base::WeakPtrFactory<MockHttpStream> weak_factory_;
 };
@@ -154,10 +158,10 @@ int MockHttpStream::ReadResponseBody(
   if (stall_reads_forever_)
     return ERR_IO_PENDING;
 
-  if (num_chunks_ == 0)
+  if (num_chunks_ == 0 && !delay_eof_chunk_)
     return ERR_UNEXPECTED;
 
-  if (buf_len > kMagicChunkSize && num_chunks_ > 1) {
+  if (buf_len > kMagicChunkSize && (num_chunks_ > 1 || delay_eof_chunk_)) {
     user_buf_ = buf;
     callback_ = callback;
     MessageLoop::current()->PostTask(
@@ -178,10 +182,15 @@ void MockHttpStream::CompleteRead() {
   std::memset(user_buf_->data(), 1, kMagicChunkSize);
   user_buf_ = NULL;
   callback_.Reset();
-  num_chunks_--;
-  if (!num_chunks_)
+  if (num_chunks_) {
+    num_chunks_--;
+    if (!num_chunks_ && !delay_eof_chunk_)
+      is_complete_ = true;
+    callback.Run(kMagicChunkSize);
+  } else {
     is_complete_ = true;
-  callback.Run(kMagicChunkSize);
+    callback.Run(0);
+  }
 }
 
 class HttpResponseBodyDrainerTest : public testing::Test {
@@ -225,6 +234,13 @@ TEST_F(HttpResponseBodyDrainerTest, DrainBodyAsyncOK) {
   EXPECT_FALSE(result_waiter_.WaitForResult());
 }
 
+TEST_F(HttpResponseBodyDrainerTest, DrainBodyAsyncDelayedOK) {
+  mock_stream_->set_num_chunks(3);
+  mock_stream_->DelayEofChunk();
+  drainer_->Start(session_);
+  EXPECT_FALSE(result_waiter_.WaitForResult());
+}
+
 TEST_F(HttpResponseBodyDrainerTest, DrainBodySizeEqualsDrainBuffer) {
   mock_stream_->set_num_chunks(
       HttpResponseBodyDrainer::kDrainBodyBufferSize / kMagicChunkSize);