input: Re-pair touch screen when monitor is plugged in

https://bugs.freedesktop.org/show_bug.cgi?id=73442

src/evdev.c

@@ -658,6 +658,7 @@ evdev_device_destroy(struct evdev_device *device)
 	close(device->fd);
 	free(device->devname);
 	free(device->devnode);
+	free(device->output_name);
 	free(device);
 }
 

src/evdev.h

@@ -55,6 +55,7 @@ struct evdev_device {
 	struct evdev_dispatch *dispatch;
 	char *devnode;
 	char *devname;
+	char *output_name;
 	int fd;
 	struct {
 		int min_x, max_x, min_y, max_y;

src/udev-seat.c

@@ -123,8 +123,9 @@ device_added(struct udev_device *udev_device, struct udev_input *input)
 
 	output_name = udev_device_get_property_value(udev_device, "WL_OUTPUT");
 	if (output_name) {
+		device->output_name = strdup(output_name);
 		wl_list_for_each(output, &c->output_list, link)
-			if (strcmp(output->name, output_name) == 0)
+			if (strcmp(output->name, device->output_name) == 0)
 				device->output = output;
 	}
 
@@ -343,6 +344,20 @@ drm_led_update(struct weston_seat *seat_base, enum weston_led leds)
 		evdev_led_update(device, leds);
 }
 
+static void
+notify_output_create(struct wl_listener *listener, void *data)
+{
+	struct udev_seat *seat = container_of(listener, struct udev_seat,
+					      output_create_listener);
+	struct evdev_device *device;
+	struct weston_output *output = data;
+
+	wl_list_for_each(device, &seat->devices_list, link)
+		if (device->output_name &&
+		    strcmp(output->name, device->output_name) == 0)
+			device->output = output;
+}
+
 static struct udev_seat *
 udev_seat_create(struct weston_compositor *c, const char *seat_name)
 {
@@ -355,6 +370,10 @@ udev_seat_create(struct weston_compositor *c, const char *seat_name)
 	weston_seat_init(&seat->base, c, seat_name);
 	seat->base.led_update = drm_led_update;
 
+	seat->output_create_listener.notify = notify_output_create;
+	wl_signal_add(&c->output_created_signal,
+		      &seat->output_create_listener);
+
 	wl_list_init(&seat->devices_list);
 	return seat;
 }
@@ -363,6 +382,7 @@ static void
 udev_seat_destroy(struct udev_seat *seat)
 {
 	weston_seat_release(&seat->base);
+	wl_list_remove(&seat->output_create_listener.link);
 	free(seat);
 }
 

src/udev-seat.h

@@ -32,6 +32,7 @@
 struct udev_seat {
 	struct weston_seat base;
 	struct wl_list devices_list;
+	struct wl_listener output_create_listener;
 };
 
 struct udev_input {
@@ -42,7 +43,6 @@ struct udev_input {
 	int enabled;
 };
 
-
 int udev_input_enable(struct udev_input *input, struct udev *udev);
 void udev_input_disable(struct udev_input *input);
 int udev_input_init(struct udev_input *input,