Bug#241034: xlibs: Meta key not working in emacs with XkbOptions altwin:left_meta_win

[Felix Kühling <fxkuehl@gmx.de>]

On Sat, 17 Apr 2004 00:50:58 +0200
barbier@linuxfr.org (Denis Barbier) wrote:

> On Wed, Mar 31, 2004 at 01:02:43PM +0200, Felix Kühling wrote:
> [...]
> > If this is a bug in Emacs then I wonder why the Meta-key works correctly
> > with altwin:meta_win but fails with altwin:left_meta_win. How is the
> > left Windows key handled differently between the two options? Should
> > there be any difference? If not then I'd suspect that it's rather a
> > problem in X.
> 
> Erwan David explained (in French) in this thread
>   http://lists.debian.org/debian-user-french-0404/msg00412.html
> and in #234081 that with altwin:left_meta_win, Mod4 is bound to Meta_L
> and Super_R.  But (X)emacs seems not to be XKB-aware, and thus it cannot
> determine whether Meta_L or Super_R is pressed when it received a Mod4
> event, and Mod4 is disabled.
> 
> If (X)emacs used XKB extensions, it could make this distinction, so one
> could argue that this is a limitation in (X)emacs.
> 
> But on the other hand, having 2 keys of distinct types (Meta and Super)
> bound to the same modifier is certainly not a good idea; if these keys
> handle different actions, binding them to different modifiers is
> natural.  This is what Erwan does in #234081 to fix this problem.
> I filed http://bugzilla.xfree86.org/show_bug.cgi?id=1344 but I am afraid
> that mapping a key to another modifier might cause other trouble, so
> let's see what upstream will propose.

Thanks for the explanation. If I understand you correctly then from the
XFree86 point of view this bug is probably a duplicate of #234081.

> 
> It seems that people use altwin:left_meta_win mostly because
> altwin:meta_win cancels AltGr, see
>   http://bugzilla.xfree86.org/show_bug.cgi?id=1341

Right, that was the reason why I went with left_meta_win.

> But this one can easily be fixed, here is a patch.  All *_win options
> are then handled in a similar manner and do not modify Alt keys.

Thanks a lot! I applied your patch in /etc/X11/xkb and am happily using
altwin:meta_win now.

> 
> Denis
> 

Felix