Fix Reload button in Database editor (#2857)

spinetoolbox/spine_db_manager.py

@@ -561,24 +561,21 @@ def clean_up(self):
         self.deleteLater()
 
     def refresh_session(self, *db_maps):
-        refreshed_db_maps = set()
-        for db_map in db_maps:
-            try:
-                worker = self._get_worker(db_map)
-            except KeyError:
-                continue
-            worker.refresh_session()
-            refreshed_db_maps.add(db_map)
-        self.receive_session_refreshed(refreshed_db_maps)
+        refreshed_db_maps = self.reset_session(*db_maps)
+        if refreshed_db_maps:
+            self.receive_session_refreshed(refreshed_db_maps)
 
     def reset_session(self, *db_maps):
+        reset_db_maps = set()
         for db_map in db_maps:
             try:
                 worker = self._get_worker(db_map)
             except KeyError:
                 continue
             worker.reset_session()
             self.undo_stack[db_map].clear()
+            reset_db_maps.add(db_map)
+        return reset_db_maps
 
     def commit_session(self, commit_msg, *dirty_db_maps, cookie=None):
         """
@@ -641,8 +638,9 @@ def notify_session_committed(self, cookie, *db_maps):
             cookie (Any): commit cookie
             *db_maps: database maps that were committed
         """
-        self.reset_session(*db_maps)
-        self.receive_session_committed(set(db_maps), cookie)
+        reset_db_maps = self.reset_session(*db_maps)
+        if reset_db_maps:
+            self.receive_session_committed(reset_db_maps, cookie)
 
     def rollback_session(self, *dirty_db_maps):
         """Rolls back the current session.