Print polygon that makes the earcutting algo panic

1 files changed, 7 insertions, 4 deletions

diff --git a/src/math/polygon/triangulate.rs b/src/math/polygon/triangulate.rs
index 4c7d952..8a18cd7 100644
--- a/src/math/polygon/triangulate.rs
+++ b/src/math/polygon/triangulate.rs
@@ -75,10 +75,13 @@ where
      */
     while polygon.corners.len() > 3 {
         // Find the ear with the highest index.
-        let ear = flags
-            .iter()
-            .rposition(|&x| (x & FLAG_EAR) != 0)
-            .expect("Polygon has more than three vertices, but no ear.");
+        let ear = match flags.iter().rposition(|&x| (x & FLAG_EAR) != 0) {
+            Some(pos) => pos,
+            None => panic!(
+                "Polygon has more than three vertices, but no ear: {:?}",
+                polygon
+            ),
+        };
 
         // Add the ear's triangle to the list.
         {