window.c: Only set input region when we have a decoration

https://bugs.freedesktop.org/show_bug.cgi?id=50490

clients/window.c

@@ -1260,6 +1260,13 @@ frame_resize_handler(struct widget *widget,
 		allocation.width = width - decoration_width;
 		allocation.height = height - decoration_height;
 
+		widget->window->input_region =
+			wl_compositor_create_region(display->compositor);
+		wl_region_add(widget->window->input_region,
+			      t->margin, t->margin,
+			      width - 2 * t->margin,
+			      height - 2 * t->margin);
+
 		opaque_margin = t->margin + t->frame_radius;
 
 		wl_list_for_each(button, &frame->buttons_list, link)
@@ -1290,13 +1297,6 @@ frame_resize_handler(struct widget *widget,
 	width = child->allocation.width + decoration_width;
 	height = child->allocation.height + decoration_height;
 
-	widget->window->input_region =
-		      wl_compositor_create_region(display->compositor);
-	wl_region_add(widget->window->input_region,
-		      t->margin, t->margin,
-		      width - 2 * t->margin,
-		      height - 2 * t->margin);
-
 	widget_set_allocation(widget, 0, 0, width, height);
 
 	if (child->opaque) {