1 files changed, 89 insertions, 0 deletions
diff --git a/browser/components/customizableui/test/browser_981305_separator_insertion.js b/browser/components/customizableui/test/browser_981305_separator_insertion.js
new file mode 100644
index 0000000000..cce18f33a2
--- /dev/null
+++ b/browser/components/customizableui/test/browser_981305_separator_insertion.js
@@ -0,0 +1,89 @@
+/* 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";
+
+var tempElements = [];
+
+function insertTempItemsIntoMenu(parentMenu) {
+  // Last element is null to insert at the end:
+  let beforeEls = [
+    parentMenu.firstElementChild,
+    parentMenu.lastElementChild,
+    null,
+  ];
+  for (let i = 0; i < beforeEls.length; i++) {
+    let sep = document.createXULElement("menuseparator");
+    tempElements.push(sep);
+    parentMenu.insertBefore(sep, beforeEls[i]);
+    let menu = document.createXULElement("menu");
+    tempElements.push(menu);
+    parentMenu.insertBefore(menu, beforeEls[i]);
+    // And another separator for good measure:
+    sep = document.createXULElement("menuseparator");
+    tempElements.push(sep);
+    parentMenu.insertBefore(sep, beforeEls[i]);
+  }
+}
+
+async function checkSeparatorInsertion(menuId, buttonId, subviewId) {
+  info("Checking for duplicate separators in " + buttonId + " widget");
+  let menu = document.getElementById(menuId);
+  insertTempItemsIntoMenu(menu);
+
+  CustomizableUI.addWidgetToArea(
+    buttonId,
+    CustomizableUI.AREA_FIXED_OVERFLOW_PANEL
+  );
+
+  await waitForOverflowButtonShown();
+
+  await document.getElementById("nav-bar").overflowable.show();
+
+  let button = document.getElementById(buttonId);
+  button.click();
+  let subview = document.getElementById(subviewId);
+  await BrowserTestUtils.waitForEvent(subview, "ViewShown");
+
+  let subviewBody = subview.firstElementChild;
+  ok(subviewBody.firstElementChild, "Subview should have a kid");
+  is(
+    subviewBody.firstElementChild.localName,
+    "toolbarbutton",
+    "There should be no separators to start with"
+  );
+
+  for (let kid of subviewBody.children) {
+    if (kid.localName == "menuseparator") {
+      ok(
+        kid.previousElementSibling &&
+          kid.previousElementSibling.localName != "menuseparator",
+        "Separators should never have another separator next to them, and should never be the first node."
+      );
+    }
+  }
+
+  let panelHiddenPromise = promiseOverflowHidden(window);
+  PanelUI.overflowPanel.hidePopup();
+  await panelHiddenPromise;
+
+  CustomizableUI.reset();
+}
+
+add_task(async function check_devtools_separator() {
+  const panelviewId = "PanelUI-developer-tools";
+
+  await checkSeparatorInsertion(
+    "menuWebDeveloperPopup",
+    "developer-button",
+    panelviewId
+  );
+});
+
+registerCleanupFunction(function () {
+  for (let el of tempElements) {
+    el.remove();
+  }
+  tempElements = null;
+});