net/http: don't write HEAD response body in ResponseWriter.ReadFrom
Responses to HEAD requests don't have a body.
The ResponseWriter automatically discards writes to the response body
when responding to a HEAD request. ResponseWriter.ReadFrom was failing
to discard writes under some circumstances; fix it to do so.
Fixes #68609
Change-Id: I912f6b2b2a535df28ae37b875fcf15b10da1af2b
Reviewed-on: https://go-review.googlesource.com/c/go/+/601475 Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Auto-Submit: Damien Neil <dneil@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: Michael Knyszek <mknyszek@google.com>