Oh, I just saw an alternative wandering in the inbox:

http://source.squeak.org/inbox/Morphic-kb.619.diff

Item was added:
+ ----- Method: DockingBarUpdatingMenuMorph>>delete (in category 'as
yet unclassified') -----
+ delete
+
+ 	owner ifNotNil: [
+ 		" When deleted remove my menu items, so I can avoid holding
unwanted references to other objects. They will be updated anyway when
I become visible again. "
+ 		" The owner notNil condition is necessary because MenuItemMorph >>
select: sends delete before I become visible, but after the menu items
are updated. "
+ 		self removeAllMorphs ].
+ 	super delete!

Nicolas

2013/1/22 Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com>:
> Yes I answered too fast without reading your answer !
> Your solution is by far simpler.
> I see that a DockingBarUpdatingMenuMorph always rebuild its menu as
> the name tells
>
> Nicolas
>
> 2013/1/22 Bert Freudenberg <bert at freudenbergs.de>:
>> But it gets rebuilt every time it is shown anyway, so why bother making it weak?
>>
>> - Bert -
>>
>> On 22.01.2013, at 13:58, Nicolas Cellier <nicolas.cellier.aka.nice at gmail.com> wrote:
>>
>>> If the menu points weakly, then it should be OK.
>>> See Morphic-nice.635 in inbox.
>>>
>>> Nicolas
>>>
>>> 2013/1/22 Bert Freudenberg <bert at freudenbergs.de>:
>>>>
>>>> On 22.01.2013, at 13:31, "H. Hirzel" <hannes.hirzel at gmail.com> wrote:
>>>>> What should we do about the 'Windows' subMenu?
>>>>>
>>>>> Rebuild it any time a menu is called? Or rebuild it any time a window is closed?
>>>>
>>>>
>>>> Nil it out as soon as the window is closed. Perhaps like this?
>>>>
>>>> DockingBarUpdatingMenuMorph>>outOfWorld: aWorld
>>>>        self removeAllMorphs.   "forget references held in menu items"
>>>>        ^super outOfWorld: aWorld
>>>>
>>>>
>>>> - Bert -
>>>>
>>>>
>>>>
>>>
>>
>>
>>