hotfix: close received after close

waitCloseHandshake waits for client to respond with close frame but handleControl receives it and writes close again which may cause errors for some clients

Author: fogrye

close.go

@@ -214,7 +214,7 @@ func (c *Conn) waitCloseHandshake() error {
 	}
 
 	for {
-		h, err := c.readLoop(ctx)
+		h, err := c.readLoop(ctx, true)
 		if err != nil {
 			return err
 		}

read.go

@@ -180,7 +180,8 @@ func (c *Conn) readRSV1Illegal(h header) bool {
 	return false
 }
 
-func (c *Conn) readLoop(ctx context.Context) (header, error) {
+func (c *Conn) readLoop(ctx context.Context, ignoreControl bool) (header, error) {
+
 	for {
 		h, err := c.readFrameHeader(ctx)
 		if err != nil {
@@ -199,6 +200,9 @@ func (c *Conn) readLoop(ctx context.Context) (header, error) {
 
 		switch h.opcode {
 		case opClose, opPing, opPong:
+			if ignoreControl {
+				return h, nil
+			}
 			err = c.handleControl(ctx, h)
 			if err != nil {
 				// Pass through CloseErrors when receiving a close frame.
@@ -344,7 +348,7 @@ func (c *Conn) reader(ctx context.Context) (_ MessageType, _ io.Reader, err erro
 		return 0, nil, errors.New("previous message not read to completion")
 	}
 
-	h, err := c.readLoop(ctx)
+	h, err := c.readLoop(ctx, false)
 	if err != nil {
 		return 0, nil, err
 	}
@@ -429,7 +433,7 @@ func (mr *msgReader) read(p []byte) (int, error) {
 				return 0, io.EOF
 			}
 
-			h, err := mr.c.readLoop(mr.ctx)
+			h, err := mr.c.readLoop(mr.ctx, false)
 			if err != nil {
 				return 0, err
 			}