fix: incorrect sprite size for aabb when sprite has rect and no custom_size (#12738)

# Objective

Fixes #12736 

## Solution

Use sprite rect to calculate sprite size for aabb when custom_size is
None

crates/bevy_sprite/src/lib.rs

@@ -194,14 +194,18 @@ pub fn calculate_bounds_2d(
         }
     }
     for (entity, sprite, texture_handle, atlas) in &sprites_to_recalculate_aabb {
-        if let Some(size) = sprite.custom_size.or_else(|| match atlas {
+        if let Some(size) = sprite
+            .custom_size
+            .or_else(|| sprite.rect.map(|rect| rect.size()))
+            .or_else(|| match atlas {
                 // We default to the texture size for regular sprites
                 None => images.get(texture_handle).map(|image| image.size_f32()),
                 // We default to the drawn rect for atlas sprites
                 Some(atlas) => atlas
                     .texture_rect(&atlases)
                     .map(|rect| rect.size().as_vec2()),
-        }) {
+            })
+        {
             let aabb = Aabb {
                 center: (-sprite.anchor.as_vec() * size).extend(0.0).into(),
                 half_extents: (0.5 * size).extend(0.0).into(),
@@ -226,7 +230,7 @@ impl ExtractComponent for SpriteSource {
 #[cfg(test)]
 mod test {
 
-    use bevy_math::Vec2;
+    use bevy_math::{Rect, Vec2, Vec3A};
     use bevy_utils::default;
 
     use super::*;
@@ -336,4 +340,52 @@ mod test {
         // Check that the AABBs are not equal
         assert_ne!(first_aabb, second_aabb);
     }
+
+    #[test]
+    fn calculate_bounds_2d_correct_aabb_for_sprite_with_custom_rect() {
+        // Setup app
+        let mut app = App::new();
+
+        // Add resources and get handle to image
+        let mut image_assets = Assets::<Image>::default();
+        let image_handle = image_assets.add(Image::default());
+        app.insert_resource(image_assets);
+        let mesh_assets = Assets::<Mesh>::default();
+        app.insert_resource(mesh_assets);
+        let texture_atlas_assets = Assets::<TextureAtlasLayout>::default();
+        app.insert_resource(texture_atlas_assets);
+
+        // Add system
+        app.add_systems(Update, calculate_bounds_2d);
+
+        // Add entities
+        let entity = app
+            .world_mut()
+            .spawn((
+                Sprite {
+                    rect: Some(Rect::new(0., 0., 0.5, 1.)),
+                    anchor: Anchor::TopRight,
+                    ..default()
+                },
+                image_handle,
+            ))
+            .id();
+
+        // Create AABB
+        app.update();
+
+        // Get the AABB
+        let aabb = *app
+            .world_mut()
+            .get_entity(entity)
+            .expect("Could not find entity")
+            .get::<Aabb>()
+            .expect("Could not find AABB");
+
+        // Verify that the AABB is at the expected position
+        assert_eq!(aabb.center, Vec3A::new(-0.25, -0.5, 0.));
+
+        // Verify that the AABB has the expected size
+        assert_eq!(aabb.half_extents, Vec3A::new(0.25, 0.5, 0.));
+    }
 }