With Caps remapped, after emulating escape two times, it stops working

[dmedvinsky]

Hello. I'm having some weird issue with xcape and Caps mapped to Control. The thing is, it works only for the first two presses, and then stops. It still works with normal Control key, but not with Caps, until restarted.

Here's how I map Caps to Control:

dmedvinsky at zeus in ~
><((°> cat /etc/X11/xorg.conf.d/20-keyboard.conf 
Section "InputClass"
    Identifier "keyboard defaults"
    MatchIsKeyboard "on"
    Option "XkbLayout" "us,ru,"
    Option "XkbOptions" "grp:alt_space_toggle,compose:menu,ctrl:nocaps"
EndSection

Here's the output of xcape --debug:

dmedvinsky at zeus in ~
><((°> pgrep xcape

dmedvinsky at zeus in ~
[1] ><((ˣ> xcape --debug
sig_handler running...
Intercepted key event 3, key code 36
Intercepted key event 2, key code 66
Control pressed!
Intercepted key event 3, key code 66
Control released!
Generating ESC!
Intercepted key event 2, key code 9
Intercepted key event 3, key code 9
^[Intercepted key event 2, key code 66
Control pressed!
Intercepted key event 3, key code 66
Control released!
Generating ESC!
Intercepted key event 2, key code 9
Intercepted key event 3, key code 9
^[Intercepted key event 2, key code 66
Intercepted key event 3, key code 66

That is me running it and pressing Caps key three times in a row with a couple of seconds in between key presses and no other keys pressed.

[dmedvinsky]

Oh, I'm running latest master.

[benarmston]

As you are probably aware, the option ctrl:nocaps results in two Control_L keys. It is this duplicated key which seem to be the problem. As proof of that the following xmodmap commands also produce this problem:

remove Lock = Caps_Lock keysym Caps_Lock = Control_L

I have been able to work around this issue by using a different XkbOption, namely, caps:ctrl_modifier. This results in the caps key using the Caps_Lock keysym, but being treated as a control key. xcape can then be run with ``xcape -e 'Caps_Lock=Escape' to get the desired behaviour.

Unfortunately, it is not possible to then map the escape key to become a caps lock. As doing so results in two keys using the Caps_Lock keysym, and the crashing occurs once again.

Is support for multiple keys using the same keysym something that could be added to xcape? If so, I may take a look at doing so when time permits.

[alols]

I have been remapping Caps Lock to Control using the GUI in GNOME and that always worked. I'm not sure how to reproduce the problem on my machine running Linux Mint.

[dmedvinsky]

@benarmston Thanks for the info, I'm using caps:ctrl_modifier now in my X config, as I don't really care about remapping Esc to Caps. This way it seems to work fine.

@alols I believe you can do setxkbmap -option 'ctrl:nocaps' to try to reproduce. Although, after updating to latest master I can't reproduce it by myself anymore.

[alols]

@dmedvinsky I assume this means I can close the issue now.