net/http: do not discard body content when closing it within request handlers
(*body).Close() internally tries to discard the content of a request
body up to 256 KB. We rely on this behavior to allow connection re-use,
by calling (*body).Close() when our request handler exits.
Unfortunately, this causes an unfortunate side-effect where we would
prematurely try to discard a body content when (*body).Close() is called
from within a request handler.
There should not be a good reason for (*body).Close() to do this when
called from within a request handler. As such, this CL modifies
(*body).Close() to not discard body contents when called from within a
request handler. Note that when a request handler exits, it will still
try to discard the body content for connection re-use.
For #75933
Change-Id: I71d2431a540579184066dd35d3da49d6c85c3daf
Reviewed-on: https://go-review.googlesource.com/c/go/+/720380
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Nicholas Husin <husin@google.com> Reviewed-by: Damien Neil <dneil@google.com>