Previous to this commit, MockHttpServletRequestBuilder was not binary
compatible as its methods had moved to a parent class with a generic
argument on the return type. MockMultipartHttpServletRequestBuilder
was also not source compatible as it no longed extended from
MockHttpServletRequestBuilder.
Both these changes were introduced to allow the AssertJ support to
expose builders that implement an extra AssertJ interface, without
copying the features the builders provide.
This commit restore compatibility. For MockHttpServletRequestBuilder
we simply override all methods that returns the generic type into
the resolved type.
MockMultipartHttpServletRequestBuilder is more involved. Because we
need to extend from MockHttpServletRequestBuilder, we have no other
choice than duplicating the code. For now, the abstract builder for
multipart is only used by the AssertJ support, but we can revisit this
again in a major release.
Closes gh-33229
265299c790