Remove Rect::default() since there is no sensible default rectangle

egui/src/containers/window.rs

@@ -650,7 +650,7 @@ fn show_title_bar(
             title_label,
             title_galley,
             title_rect,
-            rect: Default::default(), // Will be filled in later
+            rect: Rect::invalid(), // Will be filled in later
         }
     });
 

egui/src/math/rect.rs

@@ -5,7 +5,7 @@ use crate::math::*;
 /// A rectangular region of space.
 ///
 /// Normally given in points, e.g. logical pixels.
-#[derive(Clone, Copy, Default, Eq, PartialEq)]
+#[derive(Clone, Copy, Eq, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Deserialize, serde::Serialize))]
 pub struct Rect {
     pub min: Pos2,
@@ -30,6 +30,14 @@ impl Rect {
         }
     }
 
+    /// invalid, NAN filled Rect.
+    pub fn invalid() -> Self {
+        Self {
+            min: pos2(f32::NAN, f32::NAN),
+            max: pos2(f32::NAN, f32::NAN),
+        }
+    }
+
     pub fn from_min_max(min: Pos2, max: Pos2) -> Self {
         Rect { min, max }
     }

egui/src/widgets/image.rs

@@ -1,6 +1,6 @@
 use crate::*;
 
-#[derive(Clone, Copy, Debug, Default)]
+#[derive(Clone, Copy, Debug)]
 pub struct Image {
     texture_id: TextureId,
     uv: Rect,
@@ -15,8 +15,8 @@ impl Image {
             texture_id,
             uv: Rect::from_min_max(pos2(0.0, 0.0), pos2(1.0, 1.0)),
             desired_size,
+            bg_fill: Default::default(),
             tint: color::WHITE,
-            ..Default::default()
         }
     }