The keyboard-state module crashes with SIGSEGV in libinput_device_ref
when a new input device appears in /dev/input/.
Three bugs fixed:
1. Missing NULL check: tryAddDevice() calls libinput_path_add_device()
which returns NULL on failure, then immediately passes the result to
libinput_device_ref() without checking. On laptops, virtual input
devices (power buttons, lid switch, etc.) appear and disappear in
/dev/input/ triggering the hotplug handler; if libinput can't open
one of these, the NULL return causes the segfault.
2. Missing cleanup on device removal: The IN_DELETE handler erased
devices from the map without calling libinput_path_remove_device(),
leaving dangling pointers in the libinput context.
3. Thread safety: libinput_devices_ was accessed from 3 threads
(main/GTK, libinput_thread_, hotplug_thread_) without any mutex.
Fixes#4851
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
13469a8847