Motivation
As part of a recent commit for issue
https://github.com/netty/netty/issues/9861 the HttpObjectDecoder was
changed to throw an IllegalArgumentException (and produce a failed
decoder result) when decoding a message with both "Transfer-Encoding:
chunked" and "Content-Length".
While it seems correct for Netty to try to sanitize these types of
messages, the spec explicitly mentions that the Content-Length header
should be *removed* in this scenario.
Both Nginx 1.15.9 and Tomcat 9.0.31 also opt to remove the header:
b693d7c198/java/org/apache/coyote/http11/Http11Processor.java (L747-L755)0ad4393e30/src/http/ngx_http_request.c (L1946-L1953)
Modifications
* Change the default behavior from throwing an IllegalArgumentException
to removing the "Content-Length" header
* Extract the behavior to a new protected method,
handleChunkedEncodingWithContentLength(), that can be overridden to
change this behavior (or capture metrics)
Result
Messages of this nature will now be successfully decoded and have their
"Content-Length" header removed, rather than creating invalid messages
(decoder result failures). Users will be allowed to override and
configure this behavior.
f4d1df9c57