Sway sends wl_keyboard modifiers event before sending keymap

[tmccombs]

• Sway Version:

  • sway version 1.9

• Description:

See emersion/slurp#123 and emersion/slurp#124

Basically slurp segfaults in some situations because it gets an event about key modifiers (wl_keyboard.modifiers) before it has received a keymap (wl_keyboard.keymap). Since it hasn't received a keymap yet, it doesn't know how to handle the modifiers event.

The following is an exceprt from the WL_DEBUG output for slurp:

[ 132030.182] [email protected](26178, wl_surface@3, array[0])
[ 132030.186] [email protected](26179, 0, 0, 0, 0)
zsh: segmentation fault (core dumped)  WAYLAND_DEBUG=1 slurp

no keymap event is received prior to this.

What should probably happens is sway makes sure that a keymap has been sent to the application before sending the enter event.

[emersion]

Reading the wlroots source code, I don't understand how this can happen.

[emersion]

Hm, I suppose it could happen if wlr_seat_keyboard_notify_modifiers() is called before wlr_seat_set_keyboard()?

The only unguarded call in Sway is in the IME code. Are you using an IME by any chance?

[tmccombs]

I'm using wtype to send keyboard events. Maybe that uses the same API as IME?

[layercak3]

wtype uses virtual keyboard, not text-input (IME). Does it still happen in master? I'm unable to get it to crash on my machine.

[tmccombs]

Yes, I can still reproduce on master. All I have to do to reproduce is run:

$ wtype no && slurp