From 61e6fdf9f7dcc69d9e097c7d95aa0abd0966953c Mon Sep 17 00:00:00 2001
From: me-it-is <188520719+me-it-is@users.noreply.github.com>
Date: Mon, 27 Jul 2026 19:47:51 -0700
Subject: [PATCH] fix: Ensure neither point of an arc is at the center before
 trying to add an arc Fixes: https://github.com/dimforge/rapier/issues/969

---
 src/transformation/utils.rs | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/transformation/utils.rs b/src/transformation/utils.rs
index 62dfc41f..ee379ac4 100644
--- a/src/transformation/utils.rs
+++ b/src/transformation/utils.rs
@@ -646,13 +646,14 @@ pub fn push_arc_and_idx(
     out_idx: &mut Vec<[u32; 2]>,
 ) {
     let base = out_vtx.len() as u32;
-    push_arc(
-        center,
-        out_vtx[start as usize],
-        out_vtx[end as usize],
-        nsubdivs,
-        out_vtx,
-    );
+    let start_point = out_vtx[start as usize];
+    let end_point = out_vtx[end as usize];
+    // This check is already performed inside of push_arc
+    // but cant be performed inside of push_arc_idx because it doesnt have access to the actual vertices
+    if start_point == center || end_point == center {
+        return;
+    }
+    push_arc(center, start_point, end_point, nsubdivs, out_vtx);
     push_arc_idx(start, base..base + nsubdivs - 1, end, out_idx);
 }