check if no rendered actions

Author: amunger

src/vs/workbench/contrib/notebook/browser/viewParts/notebookEditorToolbar.ts

@@ -645,15 +645,17 @@ function actionOverflowHelper(initialPrimaryActions: IActionModel[], initialSeco
 		}
 	}
 
-	for (let i = (renderActions.length - 1); i !== 0; i--) {
-		const temp = renderActions[i];
-		if (temp.size === 0) {
-			continue;
-		}
-		if (temp.action instanceof Separator) {
-			renderActions.splice(i, 1);
+	if (renderActions.length) {
+		for (let i = (renderActions.length - 1); i !== 0; i--) {
+			const temp = renderActions[i];
+			if (temp.size === 0) {
+				continue;
+			}
+			if (temp.action instanceof Separator) {
+				renderActions.splice(i, 1);
+			}
+			break;
 		}
-		break;
 	}