Minor Description
There is a small issue with the processing order of request metadata in an IPC call. The map is written for transmission before the context is passed to plugins for processing and as a result any changes that client plugins make to the metadata will not get transferred as the empty map has already been written.
Also when the response metadata is read back in it is mistakenly read into the context's request metadata instead of the response metadata. The attached patch has fixes for both of these issues.