fix window integration test

Author: kai-ion

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

@@ -14,7 +14,9 @@ namespace Http {
 class AwsChunkedIOStream : public Aws::IOStream {
 public:
     AwsChunkedIOStream(const std::shared_ptr<Aws::IOStream>& originalBody, Aws::Http::HttpRequest* request)
-        : Aws::IOStream(&m_streambuf), m_chunkStream(request, originalBody) {}
+        : Aws::IOStream(nullptr), m_chunkStream(request, originalBody), m_streambuf(m_chunkStream) {
+        rdbuf(&m_streambuf);
+    }
 
 private:
     class ChunkedStreamBuf : public std::streambuf {
@@ -42,7 +44,7 @@ class AwsChunkedIOStream : public Aws::IOStream {
     };
 
     Aws::Utils::Stream::AwsChunkedStream<> m_chunkStream;
-    ChunkedStreamBuf m_streambuf{m_chunkStream};
+    ChunkedStreamBuf m_streambuf;
 };
 
 ChunkingInterceptor::ModifyRequestOutcome ChunkingInterceptor::ModifyBeforeSigning(
@@ -62,7 +64,14 @@ ChunkingInterceptor::ModifyRequestOutcome ChunkingInterceptor::ModifyBeforeSigni
 
     request->AddContentBody(chunkedBody);
 
-    smithy::client::Utils::AppendHeaderValueToRequest(request, CONTENT_ENCODING_HEADER, AWS_CHUNKED_VALUE);
+    // Only remove Content-Length if it wasn't explicitly set
+    // If Content-Length exists, keep it and don't use Transfer-Encoding: chunked
+    if (!request->HasHeader(Aws::Http::CONTENT_LENGTH_HEADER)) {
+        request->SetHeaderValue("Transfer-Encoding", "chunked");
+    }
+    
+    // Always set aws-chunked content encoding for checksum validation
+    smithy::client::Utils::AppendHeaderValueToRequest(request, Aws::Http::CONTENT_ENCODING_HEADER, Aws::Http::AWS_CHUNKED_VALUE);
 
     return request;
 }
@@ -76,6 +85,9 @@ bool ChunkingInterceptor::ShouldApplyAwsChunking(const std::shared_ptr<Aws::Http
     if (!request || !request->GetContentBody()) {
         return false;
     }
+    
+    // Apply aws-chunked encoding for all requests with checksums
+    // This replaces the aws-chunked logic removed from HTTP clients
     const auto& hashPair = request->GetRequestHash();
     return hashPair.second != nullptr;
 }