[release-branch.go1.16] net/http: do not cancel request context on response body read

When sending a Request with a non-context deadline, we create a
context with a timeout. This context is canceled when closing the
response body, and also if a read from the response body returns
an error (including io.EOF).

Cancelling the context in Response.Body.Read interferes with the
HTTP/2 client cleaning up after a request is completed, and is
unnecessary: The user should always close the body, the impact
from not canceling the context is minor (the context timer leaks
until it fires).

For #49366.
Fixes #49558.

Change-Id: Ieaed866116916261d9079f71d8fea7a7b303b8fb
Reviewed-on: https://go-review.googlesource.com/c/go/+/361919
Trust: Damien Neil <dneil@google.com>
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
(cherry picked from commit 76fbd6167364fb98e3ebe946cfc16b5b84d4240e)
Reviewed-on: https://go-review.googlesource.com/c/go/+/368084
Reviewed-by: Michael Knyszek <mknyszek@google.com>

1 files changed, 0 insertions, 1 deletions

diff --git a/src/net/http/client.go b/src/net/http/client.go
index 88e2028bc3..5cb39f1c9a 100644
--- a/src/net/http/client.go
+++ b/src/net/http/client.go
@@ -940,7 +940,6 @@ func (b *cancelTimerBody) Read(p []byte) (n int, err error) {
 	if err == nil {
 		return n, nil
 	}
-	b.stop()
 	if err == io.EOF {
 		return n, err
 	}