bug#65488: 29.1; Modifiers stack when modifier keys are remapped in x-server

[Po Lu]

Johan Bengtsson <Johan.Bengtsson@iar.com> writes:

> To reproduce:
> * Map  the "windows key" to Meta_L in your x-server. Assuming the Gnome 
> environment this is done using Gnome tweaks. Set Keyboard & Mouse > 
> Additional Layout Options > Alt and Win behavior to "Meta is mapped to Win"
> * Start Emacs
> * Press "windows key + x"
>
> Emacs will then complain that "M-s-x" is unmapped.

This is a bug in GNOME we've already been appraised of several times.

Emacs now uses the XKB extension to establish the relationship between
virtual modifiers and real modifier bits within an X server, which is
capable of detecting when multiple virtual modifiers are associated with
the same modifier bit.

You probably need to run:

  $ xmodmap

ascertain which modifier bit is bound to Super, and remove the
extraneous virtual modifier from that bit.