MWE for another scene/output/damage bug

damagetest2.c

/*
 * Move the (invisible) mouse cursor to generate redraws.
 * Click to exit.
 *
 * BROKEN defined:
 *   1. wlr_output_commit
 *   2. wlr_scene_output_create
 * BROKEN undef'd:
 *   1. wlr_scene_output_create
 *   2. wlr_output_commit
 */
#define BROKEN

#define _POSIX_C_SOURCE 200809L
#include <stdlib.h>
#include <wayland-server-core.h>
#include <wlr/backend.h>
#include <wlr/types/wlr_cursor.h>
#include <wlr/types/wlr_input_device.h>
#include <wlr/types/wlr_output.h>
#include <wlr/types/wlr_output_layout.h>
#include <wlr/types/wlr_pointer.h>
#include <wlr/types/wlr_scene.h>

struct monitor {
	struct wlr_output *wlr_output;
	struct wlr_scene_output *scene_output;
	struct wl_listener frame;
};

/* variables */
static struct wl_display *dpy;
static struct wlr_scene *scene;
static struct wlr_output_layout *output_layout;

static struct wlr_cursor *cursor;

/* function implementations */
static void handle_frame(struct wl_listener *listener, void *data)
{
	struct monitor *m = wl_container_of(listener, m, frame);
	wlr_scene_output_commit(m->scene_output);
}

static void handle_new_output(struct wl_listener *listener, void *data)
{
	struct monitor *m = calloc(1, sizeof(*m));
	m->wlr_output = data;
	m->frame.notify = handle_frame;

	wl_signal_add(&m->wlr_output->events.frame, &m->frame);

	/* Place all outputs at (0, 0) with default mode */
	wlr_output_set_mode(m->wlr_output, wlr_output_preferred_mode(m->wlr_output));
	wlr_output_layout_add(output_layout, m->wlr_output, 0, 0);
	wlr_output_enable(m->wlr_output, 1);

#ifdef BROKEN
	wlr_output_commit(m->wlr_output);
	m->scene_output = wlr_scene_output_create(scene, m->wlr_output);
#else
	m->scene_output = wlr_scene_output_create(scene, m->wlr_output);
	wlr_output_commit(m->wlr_output);
#endif
}

static void handle_new_input(struct wl_listener *listener, void *data)
{
	struct wlr_input_device *device = data;
	if (device->type == WLR_INPUT_DEVICE_POINTER)
		wlr_cursor_attach_input_device(cursor, device);
}

static void handle_cursor_button(struct wl_listener *listener, void *data)
{
	struct wlr_event_pointer_button *event = data;
	if (event->state == WLR_BUTTON_RELEASED)
		wl_display_terminate(dpy);
}

static void handle_cursor_motion_absolute(struct wl_listener *listener, void *data)
{
	struct wlr_event_pointer_motion_absolute *event = data;
	wlr_cursor_warp_absolute(cursor, event->device, event->x, event->y);
}

static void handle_cursor_motion(struct wl_listener *listener, void *data)
{
	struct wlr_event_pointer_motion *event = data;
	wlr_cursor_move(cursor, event->device, event->delta_x, event->delta_y);
}

/* Global listeners */
static struct wl_listener new_output = {.notify = handle_new_output};
static struct wl_listener new_input = {.notify = handle_new_input};
static struct wl_listener cursor_button = {.notify = handle_cursor_button};
static struct wl_listener cursor_motion = {.notify = handle_cursor_motion};
static struct wl_listener cursor_motion_absolute = {.notify = handle_cursor_motion_absolute};

int
main(int argc, char *argv[])
{
	struct wlr_backend *backend;

	dpy = wl_display_create();
	backend = wlr_backend_autocreate(dpy);
	output_layout = wlr_output_layout_create();
	cursor = wlr_cursor_create();
	scene = wlr_scene_create();

	/* Scene: one rectangle */
	wlr_scene_rect_create(&scene->node, 10, 30, (float[]) {.8, .8, 1, 1});

	/* Cursor (easy way to generate some redraws) */
	wlr_cursor_attach_output_layout(cursor, output_layout);

	/* Events */
	wl_signal_add(&backend->events.new_output, &new_output);
	wl_signal_add(&backend->events.new_input, &new_input);
	wl_signal_add(&cursor->events.motion, &cursor_motion);
	wl_signal_add(&cursor->events.motion_absolute, &cursor_motion_absolute);
	wl_signal_add(&cursor->events.button, &cursor_button);

	wlr_backend_start(backend);
	wl_display_run(dpy);

	return EXIT_SUCCESS;
}