Tab bar heading fixed

Author: Rahuljagwani

src/component/TabBar.jsx

@@ -16,6 +16,9 @@ const TabBar = ({ superState, dispatcher }) => {
         if (!window.confirm('Do you confirm to close the tab? This action is irreversable.')) return;
         localStorageManager.remove(superState.graphs[i] ? superState.graphs[i].graphID : null);
         dispatcher({ type: T.REMOVE_GRAPH, payload: i });
+        if (!superState.curGraphIndex) {
+            dispatcher({ type: T.SET_CUR_INSTANCE, payload: null });
+        }
     };
     const editCur = (e) => {
         e.stopPropagation();