bug#22000: Patch addressing the menu-bar frame-resize interaction

[Stephen Berman]

On Fri, 19 Oct 2018 10:34:08 +0200 martin rudalics <rudalics@gmx.at> wrote:

>> Something very strange is going on: menu-bar-scrollbar-mode is nil by
>> default, so why am I seeing a scrollbar at all?
>
> Can you please describe the steps you performed?  Is this with -Q or
> in a session where you turned the menu bar on later?
>
>> Even stranger: with KDE I see the scrollbar, but running the same
>> emacs binary under GNOME I donʼt (and the menubar is truncated when
>> the frame is too narrow, so the functionality is fine).
>
> Is there no way to turn the scroll bar off under KDE?  Can you turn
> the scroll bar on under GNOME?
>
>> Yes. Iʼm thinking there should be no scrollbar at all.
>>
>> <Coffee kicks in>
>>
>> Iʼm seeing a *vertical* scroll bar. So probably this is just a slight
>> miscalculation of the menubar height (but then why is it different
>> under KDE than GNOME?). Would it make sense to start playing with
>> gtkutil.c:MENUBAR_STYLESHEET ?
>
> I think so.  But I'd like to see at least one or two other persons
> with sufficiently new GTKs kick in (Stephen, pretty please) so we get
> a more complete picture of which problems may occur.

I've applied the patches in
https://lists.gnu.org/archive/html/bug-gnu-emacs/2018-10/msg00514.html
to current master and everything seems to be working as it should.  This
is with GTK+ 3.22.30 and Openbox using several GNOME libraries; I don't
have a complete GNOME DE but I may be able to try with KDE over the
weekend.

There are a couple of visual oddities: when the `menu-bar-scrollbar'
frame parameter has the value nil or `forced-resize' (or when the item
"Menu Bar Scroll/Truncate" of the Options->Show/Hide menu is set to
"Truncate" or "Resize Frame"), then there is no thin dividing line
between the menu bar and the tool bar (in contrast to Emacs built
without this patchset), and in addition, when a menu bar menu is open,
the dividing lines in the menu are rather thick; but when the
`menu-bar-scrollbar' frame parameter has the value `automatic', the thin
dividing line between the menu bar and the tool bar is displayed (and
the menu bar itself is noticeably thicker than in Emacs built without
this patchset), and the dividing lines in an open menu are thinner,
though not as thin as the line between the menu and tool bars (in Emacs
built without this patchset the menu dividers are just as thin as the
the divider between the menu and tool bars); with the parameter value
`always' the scroll bar replaces the dividing line between the menu and
tool bars, and the menu dividers have the same thickness as with the
`automatic' setting.

Steve Berman