Fixes #1495. Mentions should always include a URI attribute

CHANGES.md

@@ -35,6 +35,7 @@
 - #1330: Missing room name in MUC invitation popup
 - #1445: Participants list uses big font in embedded mode
 - #1465: When highlighting a roster contact, they're incorrectly shown as online
+- #1495: Mentions should always include a URI attribute
 - #1502: Fatal error when using prebind
 - #1532: Converse reloads on enter pressed in the filter box
 - #1538: Allow adding self as contact

src/headless/converse-muc.js

@@ -534,7 +534,9 @@ converse.plugins.add('converse-muc', {
                     'type': 'mention'
                 };
                 if (occupant.get('jid')) {
-                    obj.uri = `xmpp:${occupant.get('jid')}`
+                    obj.uri = `xmpp:${occupant.get('jid')}`;
+                } else {
+                    obj.uri = `xmpp:${this.get('jid')}/${occupant.get('nick')}`;
                 }
                 return obj;
             },