Merge branch 'main' of https://github.com/gorilla/websocket

client.go

@@ -305,9 +305,15 @@ func (d *Dialer) DialContext(ctx context.Context, urlStr string, requestHeader h
 		})
 	}
 
+	// Close the network connection when returning an error. The variable
+	// netConn is set to nil before the success return at the end of the
+	// function.
 	defer func() {
 		if netConn != nil {
-			netConn.Close()
+			// It's safe to ignore the error from Close() because this code is
+			// only executed when returning a more important error to the
+			// application.
+			_ = netConn.Close()
 		}
 	}()
 
@@ -398,8 +404,14 @@ func (d *Dialer) DialContext(ctx context.Context, urlStr string, requestHeader h
 	resp.Body = io.NopCloser(bytes.NewReader([]byte{}))
 	conn.subprotocol = resp.Header.Get("Sec-Websocket-Protocol")
 
-	netConn.SetDeadline(time.Time{})
-	netConn = nil // to avoid close in defer.
+	if err := netConn.SetDeadline(time.Time{}); err != nil {
+		return nil, resp, err
+	}
+
+	// Success! Set netConn to nil to stop the deferred function above from
+	// closing the network connection.
+	netConn = nil
+
 	return conn, resp, nil
 }
 

client_server_test.go

@@ -522,7 +522,7 @@ func TestNoUpgrade(t *testing.T) {
 	}
 	resp.Body.Close()
 	if u := resp.Header.Get("Upgrade"); u != "websocket" {
-		t.Errorf("Uprade response header is %q, want %q", u, "websocket")
+		t.Errorf("Upgrade response header is %q, want %q", u, "websocket")
 	}
 	if resp.StatusCode != http.StatusUpgradeRequired {
 		t.Errorf("Status = %d, want %d", resp.StatusCode, http.StatusUpgradeRequired)
@@ -578,7 +578,7 @@ func TestRespOnBadHandshake(t *testing.T) {
 
 	s := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(expectedStatus)
-		io.WriteString(w, expectedBody)
+		_, _ = io.WriteString(w, expectedBody)
 	}))
 	defer s.Close()
 
@@ -828,7 +828,7 @@ func TestSocksProxyDial(t *testing.T) {
 		}
 		defer c1.Close()
 
-		c1.SetDeadline(time.Now().Add(30 * time.Second))
+		_ = c1.SetDeadline(time.Now().Add(30 * time.Second))
 
 		buf := make([]byte, 32)
 		if _, err := io.ReadFull(c1, buf[:3]); err != nil {
@@ -867,10 +867,10 @@ func TestSocksProxyDial(t *testing.T) {
 		defer c2.Close()
 		done := make(chan struct{})
 		go func() {
-			io.Copy(c1, c2)
+			_, _ = io.Copy(c1, c2)
 			close(done)
 		}()
-		io.Copy(c2, c1)
+		_, _ = io.Copy(c2, c1)
 		<-done
 	}()
 

compression.go

@@ -34,7 +34,11 @@ func decompressNoContextTakeover(r io.Reader) io.ReadCloser {
 		"\x01\x00\x00\xff\xff"
 
 	fr, _ := flateReaderPool.Get().(io.ReadCloser)
-	fr.(flate.Resetter).Reset(io.MultiReader(r, strings.NewReader(tail)), nil)
+	mr := io.MultiReader(r, strings.NewReader(tail))
+	if err := fr.(flate.Resetter).Reset(mr, nil); err != nil {
+		// Reset never fails, but handle error in case that changes.
+		fr = flate.NewReader(mr)
+	}
 	return &flateReadWrapper{fr}
 }
 

compression_test.go

@@ -22,7 +22,7 @@ func TestTruncWriter(t *testing.T) {
 			if m > n {
 				m = n
 			}
-			w.Write(p[:m])
+			_, _ = w.Write(p[:m])
 			p = p[m:]
 		}
 		if b.String() != data[:len(data)-len(w.p)] {
@@ -46,7 +46,7 @@ func BenchmarkWriteNoCompression(b *testing.B) {
 	messages := textMessages(100)
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		c.WriteMessage(TextMessage, messages[i%len(messages)])
+		_ = c.WriteMessage(TextMessage, messages[i%len(messages)])
 	}
 	b.ReportAllocs()
 }
@@ -59,7 +59,7 @@ func BenchmarkWriteWithCompression(b *testing.B) {
 	c.newCompressionWriter = compressNoContextTakeover
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		c.WriteMessage(TextMessage, messages[i%len(messages)])
+		_ = c.WriteMessage(TextMessage, messages[i%len(messages)])
 	}
 	b.ReportAllocs()
 }

conn.go

@@ -391,7 +391,9 @@ func (c *Conn) read(n int) ([]byte, error) {
 	if err == io.EOF {
 		err = errUnexpectedEOF
 	}
-	c.br.Discard(len(p))
+	// Discard is guaranteed to succeed because the number of bytes to discard
+	// is less than or equal to the number of bytes buffered.
+	_, _ = c.br.Discard(len(p))
 	return p, err
 }
 
@@ -412,7 +414,9 @@ func (c *Conn) write(frameType int, deadline time.Time, buf0, buf1 []byte) error
 		return ErrNilNetConn
 	}
 
-	c.conn.SetWriteDeadline(deadline)
+	if err := c.conn.SetWriteDeadline(deadline); err != nil {
+		return c.writeFatal(err)
+	}
 	if len(buf1) == 0 {
 		_, err = c.conn.Write(buf0)
 	} else {
@@ -422,7 +426,7 @@ func (c *Conn) write(frameType int, deadline time.Time, buf0, buf1 []byte) error
 		return c.writeFatal(err)
 	}
 	if frameType == CloseMessage {
-		c.writeFatal(ErrCloseSent)
+		_ = c.writeFatal(ErrCloseSent)
 	}
 	return nil
 }
@@ -464,21 +468,27 @@ func (c *Conn) WriteControl(messageType int, data []byte, deadline time.Time) er
 		maskBytes(key, 0, buf[6:])
 	}
 
-	d := 1000 * time.Hour
-	if !deadline.IsZero() {
-		d = deadline.Sub(time.Now())
+	if deadline.IsZero() {
+		// No timeout for zero time.
+		<-c.mu
+	} else {
+		d := time.Until(deadline)
 		if d < 0 {
 			return errWriteTimeout
 		}
+		select {
+		case <-c.mu:
+		default:
+			timer := time.NewTimer(d)
+			select {
+			case <-c.mu:
+				timer.Stop()
+			case <-timer.C:
+				return errWriteTimeout
+			}
+		}
 	}
 
-	timer := time.NewTimer(d)
-	select {
-	case <-c.mu:
-		timer.Stop()
-	case <-timer.C:
-		return errWriteTimeout
-	}
 	defer func() { c.mu <- struct{}{} }()
 
 	c.writeErrMu.Lock()
@@ -491,13 +501,14 @@ func (c *Conn) WriteControl(messageType int, data []byte, deadline time.Time) er
 		return ErrNilNetConn
 	}
 
-	c.conn.SetWriteDeadline(deadline)
-	_, err = c.conn.Write(buf)
-	if err != nil {
+	if err := c.conn.SetWriteDeadline(deadline); err != nil {
+		return c.writeFatal(err)
+	}
+	if _, err = c.conn.Write(buf); err != nil {
 		return c.writeFatal(err)
 	}
 	if messageType == CloseMessage {
-		c.writeFatal(ErrCloseSent)
+		_ = c.writeFatal(ErrCloseSent)
 	}
 	return err
 }
@@ -670,7 +681,7 @@ func (w *messageWriter) flushFrame(final bool, extra []byte) error {
 	}
 
 	if final {
-		w.endMessage(errWriteClosed)
+		_ = w.endMessage(errWriteClosed)
 		return nil
 	}
 
@@ -865,7 +876,7 @@ func (c *Conn) advanceFrame() (int, error) {
 	rsv2 := p[0]&rsv2Bit != 0
 	rsv3 := p[0]&rsv3Bit != 0
 	mask := p[1]&maskBit != 0
-	c.setReadRemaining(int64(p[1] & 0x7f))
+	_ = c.setReadRemaining(int64(p[1] & 0x7f)) // will not fail because argument is >= 0
 
 	c.readDecompress = false
 	if rsv1 {
@@ -970,7 +981,8 @@ func (c *Conn) advanceFrame() (int, error) {
 		}
 
 		if c.readLimit > 0 && c.readLength > c.readLimit {
-			c.WriteControl(CloseMessage, FormatCloseMessage(CloseMessageTooBig, ""), time.Now().Add(writeWait))
+			// Make a best effort to send a close message describing the problem.
+			_ = c.WriteControl(CloseMessage, FormatCloseMessage(CloseMessageTooBig, ""), time.Now().Add(writeWait))
 			return noFrame, ErrReadLimit
 		}
 
@@ -982,7 +994,7 @@ func (c *Conn) advanceFrame() (int, error) {
 	var payload []byte
 	if c.readRemaining > 0 {
 		payload, err = c.read(int(c.readRemaining))
-		c.setReadRemaining(0)
+		_ = c.setReadRemaining(0) // will not fail because argument is >= 0
 		if err != nil {
 			return noFrame, err
 		}
@@ -1032,7 +1044,8 @@ func (c *Conn) handleProtocolError(message string) error {
 	if len(data) > maxControlFramePayloadSize {
 		data = data[:maxControlFramePayloadSize]
 	}
-	c.WriteControl(CloseMessage, data, time.Now().Add(writeWait))
+	// Make a best effor to send a close message describing the problem.
+	_ = c.WriteControl(CloseMessage, data, time.Now().Add(writeWait))
 	return errors.New("websocket: " + message)
 }
 
@@ -1111,7 +1124,7 @@ func (r *messageReader) Read(b []byte) (int, error) {
 			}
 			rem := c.readRemaining
 			rem -= int64(n)
-			c.setReadRemaining(rem)
+			_ = c.setReadRemaining(rem) // rem is guaranteed to be >= 0
 			if c.readRemaining > 0 && c.readErr == io.EOF {
 				c.readErr = errUnexpectedEOF
 			}
@@ -1211,7 +1224,8 @@ func (c *Conn) SetCloseHandler(h func(code int, text string) error) {
 	if h == nil {
 		h = func(code int, text string) error {
 			message := FormatCloseMessage(code, "")
-			c.WriteControl(CloseMessage, message, time.Now().Add(writeWait))
+			// Make a best effor to send the close message.
+			_ = c.WriteControl(CloseMessage, message, time.Now().Add(writeWait))
 			return nil
 		}
 	}
@@ -1239,7 +1253,7 @@ func (c *Conn) SetPingHandler(h func(appData string) error) {
 	}
 	if h == nil {
 		h = func(message string) error {
-			// Make a best effort to send the pong mesage.
+			// Make a best effort to send the pong message.
 			_ = c.WriteControl(PongMessage, []byte(message), time.Now().Add(writeWait))
 			return nil
 		}

conn_broadcast_test.go

@@ -69,9 +69,9 @@ func (b *broadcastBench) makeConns(numConns int) {
 				select {
 				case msg := <-c.msgCh:
 					if msg.prepared != nil {
-						c.conn.WritePreparedMessage(msg.prepared)
+						_ = c.conn.WritePreparedMessage(msg.prepared)
 					} else {
-						c.conn.WriteMessage(TextMessage, msg.payload)
+						_ = c.conn.WriteMessage(TextMessage, msg.payload)
 					}
 					val := atomic.AddInt32(&b.count, 1)
 					if val%int32(numConns) == 0 {