Bug 1404999, force command updating to be enabled when a menu is opened, r=mconley

browser/components/places/tests/browser/browser_click_bookmarks_on_toolbar.js

@@ -128,3 +128,36 @@ add_task(async function clickWithPrefSet() {
 
   await SpecialPowers.popPrefEnv();
 });
+
+// Open a tab, then quickly open the context menu to ensure that the command
+// enabled state of the menuitems is updated properly.
+add_task(async function quickContextMenu() {
+  await SpecialPowers.pushPrefEnv({set: [
+    [PREF_LOAD_BOOKMARKS_IN_TABS, true]
+  ]});
+
+  let tabPromise = BrowserTestUtils.waitForNewTab(gBrowser, TEST_PAGES[0]);
+
+  EventUtils.synthesizeMouseAtCenter(gBookmarkElements[0], {
+    button: 0
+  });
+  let newTab = await tabPromise;
+
+  let placesContext = document.getElementById("placesContext");
+  let promise = BrowserTestUtils.waitForEvent(placesContext, "popupshown");
+  EventUtils.synthesizeMouseAtCenter(gBookmarkElements[1], {
+    button: 2,
+    type: "contextmenu"
+  });
+  await promise;
+
+  Assert.ok(!document.getElementById("placesContext_open").disabled,
+            "Commands in context menu are enabled");
+
+  promise = BrowserTestUtils.waitForEvent(placesContext, "popuphidden");
+  placesContext.hidePopup();
+  await promise;
+  await BrowserTestUtils.removeTab(newTab);
+
+  await SpecialPowers.popPrefEnv();
+});

layout/xul/nsXULPopupManager.cpp

@@ -15,6 +15,8 @@
 #include "nsXULElement.h"
 #include "nsIDOMXULMenuListElement.h"
 #include "nsIXULDocument.h"
+#include "nsIDOMXULDocument.h"
+#include "nsIDOMXULCommandDispatcher.h"
 #include "nsIXULTemplateBuilder.h"
 #include "nsCSSFrameConstructor.h"
 #include "nsGlobalWindow.h"
@@ -1974,6 +1976,16 @@ nsXULPopupManager::UpdateMenuItems(nsIContent* aPopup)
     return;
   }
 
+  // When a menu is opened, make sure that command updating is unlocked first.
+  nsCOMPtr<nsIDOMXULDocument> xulDoc = do_QueryInterface(document);
+  if (xulDoc) {
+    nsCOMPtr<nsIDOMXULCommandDispatcher> xulCommandDispatcher;
+    xulDoc->GetCommandDispatcher(getter_AddRefs(xulCommandDispatcher));
+    if (xulCommandDispatcher) {
+      xulCommandDispatcher->Unlock();
+    }
+  }
+
   for (nsCOMPtr<nsIContent> grandChild = aPopup->GetFirstChild();
        grandChild;
        grandChild = grandChild->GetNextSibling()) {