Merge patch for #684

cockatrice/src/chatview.cpp

@@ -130,7 +130,7 @@ void ChatView::appendMessage(QString message, QString sender, UserLevelFlags use
     senderFormat.setAnchor(true);
     senderFormat.setAnchorHref("user://" + QString::number(userLevel) + "_" + sender);
     if (!sameSender) {
-        if (!sender.isEmpty()) {
+        if (!sender.isEmpty() && tabSupervisor->getUserListsTab()) {
             const int pixelSize = QFontInfo(cursor.charFormat().font()).pixelSize();
             QMap<QString, UserListTWI *> buddyList = tabSupervisor->getUserListsTab()->getBuddyList()->getUsers();
             cursor.insertImage(UserLevelPixmapGenerator::generatePixmap(pixelSize, userLevel, buddyList.contains(sender)).toImage());