fix window integration test

Author: kai-ion

src/aws-cpp-sdk-core/source/http/interceptor/ChunkingInterceptor.cpp

@@ -5,6 +5,7 @@
 
 #include <aws/core/http/interceptor/ChunkingInterceptor.h>
 #include <aws/core/utils/stream/AwsChunkedStream.h>
+#include <aws/core/utils/UnreferencedParam.h>
 #include <smithy/client/common/AwsSmithyClientUtils.h>
 
 namespace Aws {
@@ -18,12 +19,17 @@ class AwsChunkedIOStream : public Aws::IOStream {
 private:
     class ChunkedStreamBuf : public std::streambuf {
     public:
-        ChunkedStreamBuf(Aws::Utils::Stream::AwsChunkedStream<>& chunkStream) : m_chunkStream(chunkStream) {}
+        ChunkedStreamBuf(Aws::Utils::Stream::AwsChunkedStream<>& chunkStream) : m_chunkStream(chunkStream), m_finished(false) {}
 
     protected:
         int_type underflow() override {
+            if (m_finished) return traits_type::eof();
+            
             size_t bytesRead = m_chunkStream.BufferedRead(m_buffer, sizeof(m_buffer));
-            if (bytesRead == 0) return traits_type::eof();
+            if (bytesRead == 0) {
+                m_finished = true;
+                return traits_type::eof();
+            }
 
             setg(m_buffer, m_buffer, m_buffer + bytesRead);
             return traits_type::to_int_type(*gptr());
@@ -32,6 +38,7 @@ class AwsChunkedIOStream : public Aws::IOStream {
     private:
         Aws::Utils::Stream::AwsChunkedStream<>& m_chunkStream;
         char m_buffer[8192];
+        bool m_finished;
     };
 
     Aws::Utils::Stream::AwsChunkedStream<> m_chunkStream;