[release-branch.go1.23] crypto/tls: fix testHandshake close flakes

The flakes were introduced by me in CL 586655. It's unclear why only
FreeBSD seems affected, maybe other TCP stacks handle sending on a
half-closed connection differently, or aren't as quick to propagate the
RST over localhost.

Updates #68155

Change-Id: I32a1b474a7d6531dbab93910c23568b867629e8c
Reviewed-on: https://go-review.googlesource.com/c/go/+/602635
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>

diff --git a/src/crypto/tls/handshake_test.go b/src/crypto/tls/handshake_test.go
index bc3d23d5adc24efcb1afdca9a4674c55bf7bb98f..41c2643f2a8d28333ea643c3744f4646367b7336 100644 (file)
--- a/src/crypto/tls/handshake_test.go
+++ b/src/crypto/tls/handshake_test.go
@@ -491,9 +491,10 @@ func testHandshake(t *testing.T, clientConfig, serverConfig *Config) (serverStat
                if got := string(buf); got != sentinel {
                        t.Errorf("read %q from TLS connection, but expected %q", got, sentinel)
                }
-               if err := cli.Close(); err != nil {
-                       t.Errorf("failed to call cli.Close: %v", err)
-               }
+               // We discard the error because after ReadAll returns the server must
+               // have already closed the connection. Sending data (the closeNotify
+               // alert) can cause a reset, that will make Close return an error.
+               cli.Close()
        }()
        server := Server(s, serverConfig)
        err = server.Handshake()