desktop-shell: Position maximized surfaces on the correct output.

During a maximize event, a surface was previously always put back to
the primary output after one frame on the correct output, while keeping
its size.  This was caused by the shell surface’s last_{width,height}
not being reset when it was either fullscreen or maximized, leading to
the unmaximize/maximize dance being done at each commit.

This was introduced in 8f9d90a84b.

Changes since v1:
- Fix the actual issue instead of a symptom.

Signed-off-by: Emmanuel Gil Peyrot <emmanuel.peyrot@collabora.com>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>

desktop-shell/shell.c

@@ -2545,9 +2545,6 @@ desktop_surface_committed(struct weston_desktop_surface *desktop_surface,
 		if (shsurf->resize_edges & WL_SHELL_SURFACE_RESIZE_TOP)
 			sy = shsurf->last_height - surface->height;
 
-		shsurf->last_width = surface->width;
-		shsurf->last_height = surface->height;
-
 		weston_view_to_global_float(shsurf->view, 0, 0, &from_x, &from_y);
 		weston_view_to_global_float(shsurf->view, sx, sy, &to_x, &to_y);
 		x = shsurf->view->geometry.x + to_x - from_x;
@@ -2556,6 +2553,9 @@ desktop_surface_committed(struct weston_desktop_surface *desktop_surface,
 		weston_view_set_position(shsurf->view, x, y);
 	}
 
+	shsurf->last_width = surface->width;
+	shsurf->last_height = surface->height;
+
 	/* XXX: would a fullscreen surface need the same handling? */
 	if (surface->output) {
 		wl_list_for_each(view, &surface->views, surface_link)