bug#58406: 29.0.50; Bars refactoring?

[Po Lu via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

Manuel Giraud <manuel@ledu-giraud.fr> writes:

> I find it useful to have some visual feed back that some text is
> clickable (the mode-line is a good example of this IMO).  What do you
> mean by "no program does that anymore"?  Do you that this is done by the
> widget library?

No, I meant that no other program has highlightable menu items in their
menu bars.

>>> I understand that it is too close to Emacs 29.  Do you think the menu
>>> bar could be made to mimic some feature of the tool bar (like tab bar
>>> did)?  Or do you think it would add to the cargo cult?
>>
>> I'd rather not touch any of the *bar code before Emacs 29 is cut.  Most
>> people do not use the bars, leading to many latent bugs.  Examples:
>> mouse face not being cleared when tooltips are enabled and the mouse
>> moves outside the frame, last_tool_bar_item not being cleared in the
>> same case, and last_tab_bar_item not being cleared, leading to mouse
>> highlight not working after the mouse is released outside a frame.
>>
>> These bugs are particularly nasty because they only happen in rare
>> situations, but can completely ruin the visual appearance of a frame
>> when they do.
>
> Ok, maybe I could look into them as an exercise on xdisp.c

The bugs previously mentioned were fixed, I'm just afraid that trying to
merge the tool bar and tab bar code will introduce more similar, nasty,
bugs.