Fix bad close handshake logic

This doesn't affect real world applications due to buffering but
the testss would occasionally fail on CI due to the code not handling
an immediate close after writing the close frame while resetting
the write timeout.

Author: nhooyr

close_notjs.go

@@ -44,6 +44,7 @@ func (c *Conn) closeHandshake(code StatusCode, reason string) (err error) {
 	if CloseStatus(closeHandshakeErr) == -1 {
 		return closeHandshakeErr
 	}
+
 	return nil
 }
 
@@ -63,23 +64,28 @@ func (c *Conn) writeClose(code StatusCode, reason string) error {
 		Reason: reason,
 	}
 
-	// TODO one problem with this is that if the connection is actually closed in the meantime, the error returned below will be this one lol.
-	c.setCloseErr(fmt.Errorf("sent close frame: %w", ce))
-
 	var p []byte
-	var err error
+	var marshalErr error
 	if ce.Code != StatusNoStatusRcvd {
-		p, err = ce.bytes()
-		if err != nil {
-			log.Printf("websocket: %v", err)
+		p, marshalErr = ce.bytes()
+		if marshalErr != nil {
+			log.Printf("websocket: %v", marshalErr)
 		}
 	}
 
-	werr := c.writeControl(context.Background(), opClose, p)
-	if err != nil {
-		return err
+	writeErr := c.writeControl(context.Background(), opClose, p)
+	if CloseStatus(writeErr) != -1 {
+		// Not a real error if it's due to a close frame being received.
+		writeErr = nil
+	}
+
+	// We do this after in case there was an error writing the close frame.
+	c.setCloseErr(fmt.Errorf("sent close frame: %w", ce))
+
+	if marshalErr != nil {
+		return marshalErr
 	}
-	return werr
+	return writeErr
 }
 
 func (c *Conn) waitCloseHandshake() error {

go.sum

@@ -4,16 +4,12 @@ github.com/gobwas/pool v0.2.0 h1:QEmUOlnSjWtnpRGHF3SauEiOsy82Cup83Vf2LcMlnc8=
 github.com/gobwas/pool v0.2.0/go.mod h1:q8bcK0KcYlCgd9e7WYLm9LpyS+YeLd8JVDW6WezmKEw=
 github.com/gobwas/ws v1.0.2 h1:CoAavW/wd/kulfZmSIBt6p24n4j7tHgNVCjsfHVNUbo=
 github.com/gobwas/ws v1.0.2/go.mod h1:szmBTxLgaFppYjEmNtny/v3w89xOydFnnZMcgRRu/EM=
-github.com/golang/protobuf v1.3.3 h1:gyjaxf+svBWX08ZjK86iN9geUJF0H6gp2IRKX6Nf6/I=
-github.com/golang/protobuf v1.3.3/go.mod h1:vzj43D7+SQXF/4pzW/hwtAqwc6iTitCiVSaWz5lYuqw=
 github.com/golang/protobuf v1.3.5 h1:F768QJ1E9tib+q5Sc8MkdJi1RxLTbRcTf8LJV56aRls=
 github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
 github.com/google/go-cmp v0.4.0 h1:xsAVV57WRhGj6kEIi8ReJzQlHHqcBYCElAvkovg3B/4=
 github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/gorilla/websocket v1.4.1 h1:q7AeDBpnBk8AogcD4DSag/Ukw/KV+YhzLj2bP5HvKCM=
 github.com/gorilla/websocket v1.4.1/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
-github.com/klauspost/compress v1.10.0 h1:92XGj1AcYzA6UrVdd4qIIBrT8OroryvRvdmg/IfmC7Y=
-github.com/klauspost/compress v1.10.0/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 github.com/klauspost/compress v1.10.3 h1:OP96hzwJVBIHYU52pVTI6CczrxPvrGfgqF9N5eTO0Q8=
 github.com/klauspost/compress v1.10.3/go.mod h1:aoV0uJVorq1K+umq18yTdKaF57EivdYsUV+/s2qKfXs=
 golang.org/x/time v0.0.0-20191024005414-555d28b269f0 h1:/5xXl8Y5W96D+TtHSlonuFqGHIWVuyCkGJLwGh9JJFs=