net/smtp: add missing error check in test

Change-Id: Ifcbd9d2961073a18a250f052180248d9bf223e97
GitHub-Last-Rev: 67f97d1ca07665979504264986e25522ed6799f8
GitHub-Pull-Request: golang/go#30018
Reviewed-on: https://go-review.googlesource.com/c/go/+/160442
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/net/smtp/smtp_test.go b/src/net/smtp/smtp_test.go
index 2ad7dd0978fb89a9f4c208fac9527e14c9d0e83d..cfda0790e96398dae52961e0fdb0008c355c07c8 100644 (file)
--- a/src/net/smtp/smtp_test.go
+++ b/src/net/smtp/smtp_test.go
@@ -656,9 +656,16 @@ func TestSendMailWithAuth(t *testing.T) {
                tc := textproto.NewConn(conn)
                tc.PrintfLine("220 hello world")
                msg, err := tc.ReadLine()
-               if msg == "EHLO localhost" {
-                       tc.PrintfLine("250 mx.google.com at your service")
+               if err != nil {
+                       errCh <- fmt.Errorf("ReadLine error: %v", err)
+                       return
+               }
+               const wantMsg = "EHLO localhost"
+               if msg != wantMsg {
+                       errCh <- fmt.Errorf("unexpected response %q; want %q", msg, wantMsg)
+                       return
                }
+               err = tc.PrintfLine("250 mx.google.com at your service")
                if err != nil {
                        errCh <- fmt.Errorf("PrintfLine: %v", err)
                        return