Merge upstream/main into rfx-masks-shapes

render: upstream moved the tests_*.rs modules into crates/render/src/tests/; the branch's
tests_mask_feather.rs now lives at tests/mask_feather.rs and is registered in tests.rs.
path: rect() keeps the branch's explicit-outline version with an added NaN guard on the
roundness clamp bound (main's fix for the same panic).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

crates/path/src/boolean.rs

@@ -5,7 +5,7 @@
 //! MIT OR Apache-2.0), reworked to take and return kurbo paths directly.
 //!
 //! Inputs are closed implicitly (a filled open path is painted as if closed). The sweep splits
-//! curves at intersections and y-extrema; [`tidy_segments`] re-joins pieces that came from one
+//! curves at intersections and y-extrema; `tidy_segments` re-joins pieces that came from one
 //! input curve (exactly) or one smooth run (by least-squares refit), so results carry roughly as
 //! few vertices as the inputs. Output contours are simple and consistently oriented (holes wind
 //! opposite to their outer contour), so they fill the same under either fill rule.

crates/path/src/lib.rs

@@ -137,7 +137,9 @@ pub fn from_kurbo(path: &BezPath) -> Vec<ShapePath> {
 pub fn rect(size: [f64; 2], pos: [f64; 2], roundness: f64) -> BezPath {
     let (w, h) = (size[0].abs(), size[1].abs());
     let (x0, y0, x1, y1) = (pos[0] - w / 2.0, pos[1] - h / 2.0, pos[0] + w / 2.0, pos[1] + h / 2.0);
-    let rad = if roundness.is_finite() { roundness.clamp(0.0, w.min(h) / 2.0) } else { 0.0 };
+    let max_rad = w.min(h) / 2.0;
+    // `f64::clamp` panics on a NaN bound (both size components NaN): fall back to no roundness.
+    let rad = if roundness.is_finite() && !max_rad.is_nan() { roundness.clamp(0.0, max_rad) } else { 0.0 };
     let mut p = BezPath::new();
     if rad <= 0.0 {
         p.move_to((x1, y0));
@@ -410,6 +412,11 @@ mod tests {
         assert!(near(a, (80.0, 150.0)) && near(b, (-200.0, -130.0)), "{a:?} {b:?}");
     }
 
+    #[test]
+    fn rect_with_nan_size_does_not_panic() {
+        let _ = rect([f64::NAN, f64::NAN], [0.0, 0.0], 5.0);
+    }
+
     #[test]
     fn roundtrip_vertex_model() {
         let sp = ShapePath::ellipse([10.0, 20.0], 40.0, 30.0);

crates/path/src/trace.rs

@@ -6,7 +6,7 @@
 //!    with "outside" so every contour closes.
 //! 2. **Douglas–Peucker** simplification of each closed loop to the Tolerance (pixels).
 //! 3. **Bezier fitting**: each simplified span is fitted with one cubic (least squares with fixed
-//!    end tangents, Newton reparameterisation; [`crate::fit`]). The tangent at each vertex is the
+//!    end tangents, Newton reparameterisation; `crate::fit`). The tangent at each vertex is the
 //!    chord direction at Corner Roundness 0 (straight segments, sharp corners) and the smooth
 //!    (Catmull–Rom) direction at 100 %, blended between.
 //!