no cursor relative position for zero sized nodes

crates/bevy_ui/src/focus.rs

@@ -252,9 +252,13 @@ pub fn ui_focus_system(
  // The mouse position relative to the node
  // (0., 0.) is the top-left corner, (1., 1.) is the bottom-right corner
  // Coordinates are relative to the entire node, not just the visible region.
- let relative_cursor_position = camera_cursor_positions
- .get(&camera_entity)
- .map(|cursor_position| (*cursor_position - node_rect.min) / node_rect.size());
+ let relative_cursor_position =
+ camera_cursor_positions
+ .get(&camera_entity)
+ .and_then(|cursor_position| {
+ (node_rect.size().cmpgt(Vec2::ZERO).all())
+ .then_some((*cursor_position - node_rect.min) / node_rect.size())
+ });
 
  // If the current cursor position is within the bounds of the node's visible area, consider it for
  // clicking