From f237a091abf3690bc308c8ba7fbbf58dcf938dd9 Mon Sep 17 00:00:00 2001
From: javimixet <javibato@hotmail.com>
Date: Mon, 4 May 2026 19:25:57 +0200
Subject: [PATCH] fix issue 1296

Addresses [#1296](https://github.com/gumyr/build123d/issues/1296) by reducing radius by 1e-11 to avoid ChFi2dFilletAlgo failure when split vertex equals adjacent edge vertex.
---
 src/build123d/topology/one_d.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/build123d/topology/one_d.py b/src/build123d/topology/one_d.py
index 08e2600d..35fec1f6 100644
--- a/src/build123d/topology/one_d.py
+++ b/src/build123d/topology/one_d.py
@@ -307,6 +307,9 @@ def _solve_wire_fillet_corner_chfi2d(
         corner.connected_edges[1].wrapped,
         Plane.XY.wrapped,
     )
+  
+    if not fillet_builder.Perform(radius):
+        radius -= 1e-11
 
     vertex_point = BRep_Tool.Pnt_s(corner.vertex.wrapped)
     if (