fix data buffer of wasm filter

source/extensions/common/wasm/context.cc

@@ -1934,6 +1934,17 @@ Http::FilterDataStatus Context::decodeData(::Envoy::Buffer::Instance& data, bool
 #endif
     return Http::FilterDataStatus::Continue;
   }
+  if (buffering_request_body_) {
+    decoder_callbacks_->addDecodedData(data, false);
+    if (destroyed_) {
+      // The data adding have triggered a local reply (413) and we needn't to continue to
+      // call the VM.
+      // Note this is not perfect way. If the local reply processing is stopped by other
+      // filters, this filter will still try to call the VM. But at least we can ensure
+      // the VM has valid context.
+      return Http::FilterDataStatus::StopIterationAndBuffer;
+    }
+  }
   request_body_buffer_ = &data;
   end_of_stream_ = end_stream;
   const auto buffer = getBuffer(WasmBufferType::HttpRequestBody);
@@ -2020,6 +2031,17 @@ Http::FilterDataStatus Context::encodeData(::Envoy::Buffer::Instance& data, bool
 #endif
     return Http::FilterDataStatus::Continue;
   }
+  if (buffering_response_body_) {
+    encoder_callbacks_->addEncodedData(data, false);
+    if (destroyed_) {
+      // The data adding have triggered a local reply (413) and we needn't to continue to
+      // call the VM.
+      // Note this is not perfect way. If the local reply processing is stopped by other
+      // filters, this filter will still try to call the VM. But at least we can ensure
+      // the VM has valid context.
+      return Http::FilterDataStatus::StopIterationAndBuffer;
+    }
+  }
   response_body_buffer_ = &data;
   end_of_stream_ = end_stream;
   const auto buffer = getBuffer(WasmBufferType::HttpResponseBody);
@@ -2028,7 +2050,7 @@ Http::FilterDataStatus Context::encodeData(::Envoy::Buffer::Instance& data, bool
   buffering_response_body_ = false;
   switch (result) {
   case Http::FilterDataStatus::Continue:
-    request_body_buffer_ = nullptr;
+    response_body_buffer_ = nullptr;
     break;
   case Http::FilterDataStatus::StopIterationAndBuffer:
     buffering_response_body_ = true;