Comment 2 for bug 1718632

Yep, theory confirmed. Adding

auto* key_state = new struct wl_array;
wl_array_init(key_state);
wl_keyboard_send_enter(resource, serial, target, key_state);
wl_array_release(key_state);

to WlKeyboard::handle_event() does restore key input. That's obviously a nasty hack, need to tie keyboard focus in to the window manager.