Motivation:
In Netty, currently, the HttpPostRequestEncoder only supports POST, PUT, PATCH and OPTIONS, while the RFC 7231 allows with a warning that GET, HEAD, DELETE and CONNECT use a body too (but not TRACE where it is explicitely not allowed).
The RFC in chapter 4.3 says:
"A payload within a XXX request message has no defined semantics;
sending a payload body on a XXX request might cause some existing
implementations to reject the request."
where XXX can be replaced by one of GET, HEAD, DELETE or CONNECT.
Current usages, on particular in REST mode, tend to use those extra HttpMethods for such queries.
So this PR proposes to remove the current restrictions, leaving only TRACE as explicitely not supported.
Modification:
In the constructor, where the test is done, replacing all by checking only against TRACE, and adding one test to check that all methods are supported or not.
Result:
Fixes#6138.
56ddc47f23