input: Don't recreate the cursor sprite when only the hotspot changes

Currently we unmap and re-map the cursor when the hotspot changes which
causes spurious enter/leave events.

This changes the pointer_set_cursor() logic to avoid this.

Signed-off-by: Derek Foreman <derekf@osg.samsung.com>
Reviewed-by: Jonas Ådahl <jadahl@gmail.com>
Reviewed-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

src/input.c

@@ -1648,10 +1648,9 @@ pointer_set_cursor(struct wl_client *client, struct wl_resource *resource,
 	if (pointer->focus_serial - serial > UINT32_MAX / 2)
 		return;
 
-	if (surface) {
-		if (weston_surface_set_role(surface, "wl_pointer-cursor",
-					    resource,
-					    WL_POINTER_ERROR_ROLE) < 0)
+	if (!surface) {
+		if (pointer->sprite)
+			pointer_unmap_sprite(pointer);
 		return;
 	}
 
@@ -1659,12 +1658,15 @@ pointer_set_cursor(struct wl_client *client, struct wl_resource *resource,
 	    pointer->hotspot_x == x && pointer->hotspot_y == y)
 		return;
 
+	if (!pointer->sprite || pointer->sprite->surface != surface) {
+		if (weston_surface_set_role(surface, "wl_pointer-cursor",
+					    resource,
+					    WL_POINTER_ERROR_ROLE) < 0)
+			return;
+
 		if (pointer->sprite)
 			pointer_unmap_sprite(pointer);
 
-	if (!surface)
-		return;
-
 		wl_signal_add(&surface->destroy_signal,
 			      &pointer->sprite_destroy_listener);
 
@@ -1673,6 +1675,8 @@ pointer_set_cursor(struct wl_client *client, struct wl_resource *resource,
 		weston_surface_set_label_func(surface,
 					    pointer_cursor_surface_get_label);
 		pointer->sprite = weston_view_create(surface);
+	}
+
 	pointer->hotspot_x = x;
 	pointer->hotspot_y = y;