[Fetch API] Call endRead sooner to avoid recursive invocation

third_party/WebKit/Source/modules/fetch/BodyStreamBuffer.cpp

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "modules/fetch/BodyStreamBuffer.h"
 
 #include "bindings/core/v8/ScriptState.h"
 #include "bindings/core/v8/V8HiddenValue.h"
 #include "bindings/core/v8/WorkerOrWorkletScriptController.h"
 #include "core/dom/DOMArrayBuffer.h"
@@ skipping 214 matching lines @@
     }
     std::unique_ptr<FetchDataConsumerHandle> handle = releaseHandle();
     std::unique_ptr<FetchDataConsumerHandle> handle1, handle2;
     DataConsumerTee::create(m_scriptState->getExecutionContext(), std::move(handle), &handle1, &handle2);
     *branch1 = new BodyStreamBuffer(m_scriptState.get(), std::move(handle1));
     *branch2 = new BodyStreamBuffer(m_scriptState.get(), std::move(handle2));
 }
 
 ScriptPromise BodyStreamBuffer::pull(ScriptState* scriptState)
 {
-    ASSERT(!m_streamNeedsMore);
     ASSERT(scriptState == m_scriptState.get());
+    if (m_streamNeedsMore)
+        return ScriptPromise::castUndefined(scriptState);
     m_streamNeedsMore = true;
     processData();
     return ScriptPromise::castUndefined(scriptState);
 }
 
 ScriptPromise BodyStreamBuffer::cancel(ScriptState* scriptState, ScriptValue reason)
 {
     ASSERT(scriptState == m_scriptState.get());
     close();
     return ScriptPromise::castUndefined(scriptState);
@@ skipping 101 matching lines @@
 void BodyStreamBuffer::processData()
 {
     ASSERT(m_reader);
     while (m_streamNeedsMore) {
         const void* buffer;
         size_t available;
         WebDataConsumerHandle::Result result = m_reader->beginRead(&buffer, WebDataConsumerHandle::FlagNone, &available);
         switch (result) {
         case WebDataConsumerHandle::Ok: {
             DOMUint8Array* array = DOMUint8Array::create(static_cast<const unsigned char*>(buffer), available);
+            m_reader->endRead(available);
+            // Clear m_streamNeedsMore in order to detect a pull call.
+            m_streamNeedsMore = false;
             controller()->enqueue(array);
-            m_streamNeedsMore = controller()->desiredSize() > 0;
-            m_reader->endRead(available);
+            // If m_streamNeedsMore is true, it means that pull is called and
+            // the stream needs more data even if the desired size is not
+            // positive.
+            if (!m_streamNeedsMore)
+                m_streamNeedsMore = controller()->desiredSize() > 0;
             break;
         }
         case WebDataConsumerHandle::Done:
             close();
             return;
 
         case WebDataConsumerHandle::ShouldWait:
             return;
 
         case WebDataConsumerHandle::Busy:
@@ skipping 49 matching lines @@
         return createFetchDataConsumerHandleFromWebHandle(createDoneDataConsumerHandle());
     }
     if (isErrored)
         return createFetchDataConsumerHandleFromWebHandle(createUnexpectedErrorDataConsumerHandle());
 
     DCHECK(handle);
     return handle;
 }
 
 } // namespace blink