From b7461ae97fedced0be8380591b6bc9b47e9e110b Mon Sep 17 00:00:00 2001
From: Mickael Remond <mremond@process-one.net>
Date: Sat, 8 Jun 2019 11:15:51 +0200
Subject: [PATCH] Do not reconnect on "connection replaced" stream errors

Fix #45
---
 client.go         | 20 +++++++++++++++++++-
 client_manager.go | 10 +++++++---
 stream.go         |  1 +
 3 files changed, 27 insertions(+), 4 deletions(-)

diff --git a/client.go b/client.go
index ca6c95a..c3a2802 100644
--- a/client.go
+++ b/client.go
@@ -21,6 +21,7 @@ const (
 	StateDisconnected ConnState = iota
 	StateConnected
 	StateSessionEstablished
+	StateStreamError
 )
 
 // Event is a structure use to convey event changes related to client state. This
@@ -28,6 +29,7 @@ const (
 type Event struct {
 	State       ConnState
 	Description string
+	StreamError string
 }
 
 // EventHandler is use to pass events about state of the connection to
@@ -49,6 +51,13 @@ func (em EventManager) updateState(state ConnState) {
 	}
 }
 
+func (em EventManager) streamError(error, desc string) {
+	em.CurrentState = StateStreamError
+	if em.Handler != nil {
+		em.Handler(Event{State: em.CurrentState, StreamError: error, Description: desc})
+	}
+}
+
 // Client
 // ============================================================================
 
@@ -164,8 +173,17 @@ func (c *Client) recv() (err error) {
 			c.updateState(StateDisconnected)
 			return err
 		}
+
+		// Handle stream errors
+		switch packet := val.(type) {
+		case StreamError:
+			c.RecvChannel <- val
+			close(c.RecvChannel)
+			c.streamError(packet.Error.Local, packet.Text)
+			return errors.New("stream error: " + packet.Error.Local)
+		}
+
 		c.RecvChannel <- val
-		val = nil
 	}
 }
 
diff --git a/client_manager.go b/client_manager.go
index 662aad4..75599be 100644
--- a/client_manager.go
+++ b/client_manager.go
@@ -40,6 +40,12 @@ func (cm *ClientManager) Start() error {
 		case StateDisconnected:
 			// Reconnect on disconnection
 			cm.connect()
+		case StateStreamError:
+			cm.Client.Disconnect()
+			// Only try reconnecting if we have not been kicked by another session to avoid connection loop.
+			if e.StreamError != "conflict" {
+				cm.connect()
+			}
 		}
 	}
 
@@ -62,8 +68,6 @@ func (cm *ClientManager) connect() error {
 		// TODO: Make it possible to define logger to log disconnect and reconnection attempts
 		cm.Metrics = initMetrics()
 
-		// TODO: Test for non recoverable errors (invalid username and password) and return an error
-		//   to start caller. We do not want to retry on non recoverable errors.
 		if cm.Client.Session, err = cm.Client.Connect(); err != nil {
 			var actualErr ConnError
 			if xerrors.As(err, &actualErr) {
@@ -72,7 +76,7 @@ func (cm *ClientManager) connect() error {
 				}
 			}
 			backoff.Wait()
-		} else {
+		} else { // We are connected, we can leave the retry loop
 			break
 		}
 	}
diff --git a/stream.go b/stream.go
index 1e0df97..a66ac85 100644
--- a/stream.go
+++ b/stream.go
@@ -37,6 +37,7 @@ func (streamFeatureDecoder) decode(p *xml.Decoder, se xml.StartElement) (StreamF
 type StreamError struct {
 	XMLName xml.Name `xml:"http://etherx.jabber.org/streams error"`
 	Error   xml.Name `xml:",any"`
+	Text    string   `xml:"urn:ietf:params:xml:ns:xmpp-streams text"`
 }
 
 func (StreamError) Name() string {