1 files changed, 37 insertions, 0 deletions
diff --git a/browser/components/customizableui/test/browser_956602_remove_special_widget.js b/browser/components/customizableui/test/browser_956602_remove_special_widget.js
new file mode 100644
index 0000000000..237103b79e
--- /dev/null
+++ b/browser/components/customizableui/test/browser_956602_remove_special_widget.js
@@ -0,0 +1,37 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+// Adding a separator and then dragging it out of the navbar shouldn't throw
+add_task(async function () {
+  try {
+    let navbar = document.getElementById("nav-bar");
+    let separatorSelector =
+      "toolbarseparator[id^=customizableui-special-separator]";
+    ok(
+      !navbar.querySelector(separatorSelector),
+      "Shouldn't be a separator in the navbar"
+    );
+    CustomizableUI.addWidgetToArea("separator", "nav-bar");
+    await startCustomizing();
+    let separator = navbar.querySelector(separatorSelector);
+    ok(separator, "There should be a separator in the navbar now.");
+    let palette = document.getElementById("customization-palette");
+    simulateItemDrag(separator, palette);
+    ok(
+      !palette.querySelector(separatorSelector),
+      "No separator in the palette."
+    );
+  } catch (ex) {
+    console.error(ex);
+    ok(false, "Shouldn't throw an exception moving an item to the navbar.");
+  } finally {
+    await endCustomizing();
+  }
+});
+
+add_task(async function asyncCleanup() {
+  resetCustomization();
+});