Deformed stroke for some length values fix (#3860)

crates/typst/src/visualize/shape.rs

@@ -1108,7 +1108,7 @@ impl ControlPoints {
             + 2.0 * (o.y - c_i.y).to_raw() * (c_i.y - c_o.y).to_raw();
         let c = (c_i.x - c_o.x).to_raw().powi(2) + (c_i.y - c_o.y).to_raw().powi(2)
             - r.to_raw().powi(2);
-        let t = (-b + (b * b - 4.0 * a * c).sqrt()) / (2.0 * a);
+        let t = (-b + (b * b - 4.0 * a * c).max(0.0).sqrt()) / (2.0 * a);
         c_i + t * (o - c_i)
     }
 

tests/typ/bugs/3700-deformed-stroke.typ

@@ -0,0 +1,11 @@
+// Test shape fill & stroke for specific values that used to make the stroke
+// deformed.
+// https://github.com/typst/typst/issues/3700
+
+---
+#rect(
+  radius: 1mm,
+  width: 100%,
+  height: 10pt,
+  stroke: (left: rgb("46b3c2") + 16.0mm),
+)