[panel] Help menu item in Firefox invisible

[Michał Sawicz]

Steps to reproduce:
1. run Firefox
2. hover over the top panel
3. click on the "Help" menu
4. switch back to the Firefox window
5. press F10
6. move right to the "Help" menu

Expected result:
post-2. menu shows up, with "Help" menu being there as the last one
post-3. Help menu pops out
post-4. menu hides
post-5. "File" menu opens
post-6. "Help" menu opens

Current result:
post-2. menu shows up, but no "Help" item
post-3. no item to click on
post-6. "Help" menu opens!

Note that I have experienced that on and off recently.

[Michał Sawicz (saviq)]

dbusmenu-dumper from libdbusmenu-tools says:

[...]
      {
        "id": 8,
        "children-display": 'submenu',
        "label": ''
      }
[...]

Looks like the label is empty for some reason, and that's why the menu button isn't there (0-width).

[Michał Sawicz (saviq)]

Executing com.canonical.AppMenu.Registrar.GetMenus() on com.canonical.Unity.Panel.Service fixes the issue until I restart Firefox.

Maybe also helpful: I'm on pl_PL.UTF-8 locale, and the menu shortcut is the very last letter in the label.