Merge pull request #5373 from storytold/fix/sec-dash-period-overflow

Dashes: a pattern whose period overflows to infinity draws solid

crates/effects/src/stroke/dash.rs

@@ -57,6 +57,10 @@ pub fn dash(bp: &BezPath, d: &Dash) -> Option<Dashed> {
         pat.extend_from_within(..);
     }
     let period: f64 = pat.iter().sum();
+    // Finite entries can still sum to infinity, which would never leave the phase loop below.
+    if !period.is_finite() {
+        return None;
+    }
     let plans: Vec<Plan> = subpaths(bp)
         .into_iter()
         .map(|(r, closed)| {

crates/effects/src/stroke/tests.rs

@@ -21,6 +21,11 @@ fn stroke(width: f64, f: impl FnOnce(&mut StrokeLayer)) -> StrokeLayer {
     st
 }
 
+#[test]
+fn dash_period_overflowing_to_infinity_is_solid() {
+    assert!(dash(&line(0.0, 60.0), &dashed(&[f64::MAX, f64::MAX], -1.0)).is_none());
+}
+
 fn dashed(pattern: &[f64], offset: f64) -> Dash {
     Dash { pattern: pattern.to_vec(), offset, align_corners: false }
 }