Determine why transferTo tests fail for Undertow

[poutsma]

With the introduction of the DefaultMultipartParser, two tests started failing when running against Undertow:

1. org.springframework.web.reactive.function.MultipartIntegrationTests#transferTo and
2. org.springframework.web.reactive.result.method.annotation.MultipartIntegrationTests#transferTo.

As temporary workaround the tests were disabled for 5.3 M1, but this needs to be resolved by M2.

[gregw]

I'm working on a Jetty Core integration that is similar to undertow in that it is a fully asynchronous integration without servlets. We are also failing MultipartWebClientIntegrationTests#transferTo, with the data received not being the correct value.

However, if we copy the bytebuffers as we create the DataBuffer wrappers around the jetty buffer abstraction. We see no leaks of either DataBuffer references, nor the underlying jetty RetainableByteBuffer. Thus our current best theory is that this test is accessing the databuffer after it has been released.

So maybe this is a bad test?? How is undertow failing this test?

[gregw]

Strangely enough we are also failing org.springframework.web.reactive.function.MultipartRouterFunctionIntegrationTests#proxy, which undertow also is failing. We fail this one with a leak and read after the channel is complete. Is there an issue for this test as well?