render: don't warn when rendering an unmapped sub-surface

src/ifs/wl_surface/cursor.rs

@@ -76,7 +76,15 @@ impl Cursor for CursorSurface {
                 let (hot_x, hot_y) = (Fixed::from_int(hot_x), Fixed::from_int(hot_y));
                 let x = ((x - hot_x).to_f64() * scale).round() as _;
                 let y = ((y - hot_y).to_f64() * scale).round() as _;
-                renderer.render_surface_scaled(&self.surface, x, y, None, i32::MAX, i32::MAX);
+                renderer.render_surface_scaled(
+                    &self.surface,
+                    x,
+                    y,
+                    None,
+                    i32::MAX,
+                    i32::MAX,
+                    false,
+                );
             } else {
                 renderer.render_surface(
                     &self.surface,

src/renderer.rs

@@ -307,7 +307,7 @@ impl Renderer<'_> {
         max_height: i32,
     ) {
         let (x, y) = self.base.scale_point(x, y);
-        self.render_surface_scaled(surface, x, y, None, max_width, max_height);
+        self.render_surface_scaled(surface, x, y, None, max_width, max_height, false);
     }
 
     pub fn render_surface_scaled(
@@ -318,12 +318,13 @@ impl Renderer<'_> {
         pos_rel: Option<(i32, i32)>,
         max_width: i32,
         max_height: i32,
+        is_subsurface: bool,
     ) {
         let children = surface.children.borrow();
         let buffer = match surface.buffer.get() {
             Some(b) => b,
             _ => {
-                if !surface.is_cursor() {
+                if !surface.is_cursor() && !is_subsurface {
                     log::warn!("surface has no buffer attached");
                 }
                 return;
@@ -354,6 +355,7 @@ impl Renderer<'_> {
                             Some((pos.x1(), pos.y1())),
                             max_width,
                             max_height,
+                            true,
                         );
                     }
                 };