fix(core): Prevent resource binding if we already have a resource

packages/moxxmpp/lib/src/connection.dart

@@ -270,6 +270,7 @@ class XmppConnection {
       negotiator.register(
         NegotiatorAttributes(
           sendRawXML,
+          () => this,
           () => _connectionSettings,
           _sendEvent,
           getNegotiatorById,

packages/moxxmpp/lib/src/negotiators/negotiator.dart

@@ -1,5 +1,6 @@
 import 'package:meta/meta.dart';
 import 'package:moxlib/moxlib.dart';
+import 'package:moxxmpp/src/connection.dart';
 import 'package:moxxmpp/src/errors.dart';
 import 'package:moxxmpp/src/events.dart';
 import 'package:moxxmpp/src/jid.dart';
@@ -28,6 +29,7 @@ abstract class NegotiatorError extends XmppError {}
 class NegotiatorAttributes {
   const NegotiatorAttributes(
     this.sendNonza,
+    this.getConnection,
     this.getConnectionSettings,
     this.sendEvent,
     this.getNegotiatorById,
@@ -46,7 +48,10 @@ class NegotiatorAttributes {
   /// Returns the connection settings.
   final ConnectionSettings Function() getConnectionSettings;
 
-  /// Send an event event to the connection's event bus
+  /// Returns the connection object.
+  final XmppConnection Function() getConnection;
+
+  /// Send an event event to the connection's event bus.
   final Future<void> Function(XmppEvent event) sendEvent;
 
   /// Returns the negotiator with id id of the connection or null.

packages/moxxmpp/lib/src/negotiators/resource_binding.dart

@@ -30,10 +30,13 @@ class ResourceBindingNegotiator extends XmppFeatureNegotiatorBase {
     if (sm != null) {
       return super.matchesFeature(features) &&
           !sm.streamResumed &&
-          attributes.isAuthenticated();
+          attributes.isAuthenticated() &&
+          attributes.getConnection().resource.isEmpty;
     }
 
-    return super.matchesFeature(features) && attributes.isAuthenticated();
+    return super.matchesFeature(features) &&
+        attributes.isAuthenticated() &&
+        attributes.getConnection().resource.isEmpty;
   }
 
   @override

packages/moxxmpp/test/sasl/scram_test.dart

@@ -46,6 +46,11 @@ void main() {
     )..register(
         NegotiatorAttributes(
           (XMLNode _, {String? redact}) {},
+          () => XmppConnection(
+            TestingReconnectionPolicy(),
+            AlwaysConnectedConnectivityManager(),
+            fakeSocket,
+          ),
           () => ConnectionSettings(
             jid: JID.fromString('user@server'),
             password: 'pencil',
@@ -142,6 +147,11 @@ void main() {
     )..register(
         NegotiatorAttributes(
           (XMLNode n, {String? redact}) => lastMessage = n.innerText(),
+          () => XmppConnection(
+            TestingReconnectionPolicy(),
+            AlwaysConnectedConnectivityManager(),
+            StubTCPSocket([]),
+          ),
           () => ConnectionSettings(
             jid: JID.fromString('user@server'),
             password: 'pencil',
@@ -193,6 +203,11 @@ void main() {
     )..register(
         NegotiatorAttributes(
           (XMLNode _, {String? redact}) {},
+          () => XmppConnection(
+            TestingReconnectionPolicy(),
+            AlwaysConnectedConnectivityManager(),
+            StubTCPSocket([]),
+          ),
           () => ConnectionSettings(
             jid: JID.fromString('user@server'),
             password: 'pencil',
@@ -234,6 +249,11 @@ void main() {
     )..register(
         NegotiatorAttributes(
           (XMLNode _, {String? redact}) {},
+          () => XmppConnection(
+            TestingReconnectionPolicy(),
+            AlwaysConnectedConnectivityManager(),
+            StubTCPSocket([]),
+          ),
           () => ConnectionSettings(
             jid: JID.fromString('user@server'),
             password: 'pencil',
@@ -278,6 +298,11 @@ void main() {
     )..register(
         NegotiatorAttributes(
           (XMLNode _, {String? redact}) {},
+          () => XmppConnection(
+            TestingReconnectionPolicy(),
+            AlwaysConnectedConnectivityManager(),
+            StubTCPSocket([]),
+          ),
           () => ConnectionSettings(
             jid: JID.fromString('user@server'),
             password: 'pencil',