As I read the RFC, it says that, when there are both Transfer-Encoding and Content-Length headers, the latter (which means Content-Length, because it is listed last in this sentence) MUST be dropped. It is the only thing that makes sense in this situation.
So keeping Content-Length and dropping Transfer-Encoding is
a) the wrong thing to do and
b) violating this RFC.
As I read the RFC, it says that, when there are both Transfer-Encoding and Content-Length headers, the latter (which means Content-Length, because it is listed last in this sentence) MUST be dropped. It is the only thing that makes sense in this situation.
So keeping Content-Length and dropping Transfer-Encoding is
a) the wrong thing to do and
b) violating this RFC.