[AD] X11 keyboard driver missing key up events

[Trent Gamblin <trent@xxxxxxxxxx>]

With the attached test program, if I hold space and move the arrows left
and right a bit, then release keys, the left and/or right arrow KEY_UP
events never come. Here's the output I get (notice the missing UP: 83):

DN: 83
UP: 83
DN: 83
DN: 75
DN: 78
UP: 78
DN: 78
UP: 78
DN: 78
UP: 78
DN: 79
UP: 79
DN: 79
UP: 79
DN: 79
UP: 79
UP: 75

#include <allegro5/allegro.h>
#include <cstdio>

ALLEGRO_EVENT_QUEUE *queue;

void *thread(void *data)
{
	while (1) {
		ALLEGRO_EVENT e;
		if (!al_event_queue_is_empty(queue)) {
			al_get_next_event(queue, &e);
			if (e.type == ALLEGRO_EVENT_KEY_DOWN)
				printf("DN: %d\n", e.keyboard.keycode);
			else if (e.type == ALLEGRO_EVENT_KEY_UP)
				printf("UP: %d\n", e.keyboard.keycode);
		}
		al_rest(0.01);
	}
	return NULL;
}

int main(void)
{
	al_init();
	al_install_keyboard();
	ALLEGRO_DISPLAY *d = al_create_display(640, 480);
	queue = al_create_event_queue();
	al_register_event_source(queue, al_get_keyboard_event_source());

	thread(NULL);
//	al_run_detached_thread(thread, NULL);

	al_rest(120);
}