net/http/httptest: record failed ResponseWriter writes
CL 709335 changed ResponseWriter.Write to return an error
when trying to write to a response with a status code which
doesn't permit a body, such as 304.
Continue to return an error, but still record the write in
ResponseWriter.Body. This maintains the documented property that
"the data in buf is written to rw.Body".
For #75471
Change-Id: I69139797559fe09d6580c5d25b4458f04263c60e
Reviewed-on: https://go-review.googlesource.com/c/go/+/711940 Reviewed-by: Sean Liao <sean@liao.dev>
TryBot-Bypass: Damien Neil <dneil@google.com>
Auto-Submit: Damien Neil <dneil@google.com> Reviewed-by: Nicholas Husin <nsh@golang.org> Reviewed-by: Nicholas Husin <husin@google.com>