I somehow managed to break pedestrian rendering in 004ca95842

geom/src/circle.rs

@@ -67,16 +67,17 @@ impl Circle {
 
     /// Returns the ring around the circle.
     fn to_ring(&self) -> Ring {
-        Ring::must_new(
-            (0..=TRIANGLES_PER_CIRCLE)
+        let mut pts: Vec<Pt2D> = (0..=TRIANGLES_PER_CIRCLE)
             .map(|i| {
                 self.center.project_away(
                     self.radius,
                     Angle::degrees((i as f64) / (TRIANGLES_PER_CIRCLE as f64) * 360.0),
                 )
             })
-                .collect(),
-        )
+            .collect();
+        // With some radii, we get duplicate adjacent points
+        pts.dedup();
+        Ring::must_new(pts)
     }
 
     /// Creates an outline around the circle, strictly contained with the circle's original radius.