Read incoming start element explicit part of sending outgoing start element.

src/xmpp/client.go

@@ -85,12 +85,12 @@ func startClient(stream *Stream, jid JID) error {
 		},
 	}
 
-	if err := stream.SendStart(&start); err != nil {
-		return err
-	}
-
-	if _, err := stream.Next(&xml.Name{nsStream, "stream"}); err != nil {
+	if rstart, err := stream.SendStart(&start); err != nil {
 		return err
+	} else {
+		if rstart.Name != (xml.Name{nsStream, "stream"}) {
+			return fmt.Errorf("unexpected start element: %s", rstart.Name)
+		}
 	}
 
 	return nil

src/xmpp/component.go

@@ -33,24 +33,25 @@ func startComponent(stream *Stream, jid JID) (string, error) {
 		},
 	}
 
-	if err := stream.SendStart(&start); err != nil {
-		return "", err
-	}
+	var streamId string
 
-	streamId := ""
-	if e, err := stream.Next(&xml.Name{nsStream, "stream"}); err != nil {
+	if rstart, err := stream.SendStart(&start); err != nil {
 		return "", err
 	} else {
+		if rstart.Name != (xml.Name{nsStream, "stream"}) {
+			return "", fmt.Errorf("unexpected start element: %s", rstart.Name)
+		}
 		// Find the stream id.
-		for _, attr := range e.Attr {
+		for _, attr := range rstart.Attr {
 			if attr.Name.Local == "id" {
 				streamId = attr.Value
 				break
 			}
 		}
-		if streamId == "" {
-			return "", errors.New("Missing stream id")
-		}
+	}
+
+	if streamId == "" {
+		return "", errors.New("Missing stream id")
 	}
 
 	return streamId, nil

src/xmpp/stream.go

@@ -55,12 +55,19 @@ func (stream *Stream) UpgradeTLS(config *tls.Config) error {
 }
 
 // Send the element's start tag. Typically used to open the stream's document.
-func (stream *Stream) SendStart(start *xml.StartElement) error {
+func (stream *Stream) SendStart(start *xml.StartElement) (*xml.StartElement, error) {
+
+	// Write start of outgoing doc.
 	buf := new(bytes.Buffer)
 	if err := writeXMLStartElement(buf, start); err != nil {
-		return err
+		return nil, err
 	}
-	return stream.send(buf.Bytes())
+	if err := stream.send(buf.Bytes()); err != nil {
+		return nil, err
+	}
+
+	// Read and return start of incoming doc.
+	return nextStartElement(stream.dec)
 }
 
 // Send a stanza. Used to write a complete, top-level element.
@@ -85,8 +92,19 @@ func (stream *Stream) send(b []byte) error {
 // Bad things are very likely to happen if a call to Next() is successful but
 // you don't actually decode or skip the element.
 func (stream *Stream) Next(match *xml.Name) (*xml.StartElement, error) {
+	start, err := nextStartElement(stream.dec)
+	if err != nil {
+		return nil, err
+	}
+	if match != nil && start.Name != *match {
+		return nil, fmt.Errorf("Expected %s, got %s", *match, start.Name)
+	}
+	return start, nil
+}
+
+func nextStartElement(dec *xml.Decoder) (*xml.StartElement, error) {
 	for {
-		t, err := stream.dec.Token()
+		t, err := dec.Token()
 		if err != nil {
 			if err == io.EOF {
 				err = io.ErrUnexpectedEOF
@@ -95,9 +113,6 @@ func (stream *Stream) Next(match *xml.Name) (*xml.StartElement, error) {
 		}
 		switch e := t.(type) {
 		case xml.StartElement:
-			if match != nil && e.Name != *match {
-				return nil, fmt.Errorf("Expected %s, got %s", *match, e.Name)
-			}
 			return &e, nil
 		case xml.EndElement:
 			log.Printf("EOF due to %s\n", e.Name)