From 0ef241bf1c718d897274cf95f43712399d45a7ee Mon Sep 17 00:00:00 2001
From: Davide Bazzi <davidebazzi@pcam.com>
Date: Tue, 30 Jun 2026 15:20:19 +0200
Subject: [PATCH] The Clone method of the SphericalSurface didn't copy the
 usedArea. This will cause exception when computing the intersection of a
 spline with a sphere.

---
 CADability/SphericalSurface.cs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CADability/SphericalSurface.cs b/CADability/SphericalSurface.cs
index cc575a4e2..cca3a8404 100644
--- a/CADability/SphericalSurface.cs
+++ b/CADability/SphericalSurface.cs
@@ -516,7 +516,7 @@ public override void GetZMinMax(Projection p, double umin, double umax, double v
 		/// <returns></returns>
 		public override ISurface Clone()
 		{
-			return new SphericalSurface(toSphere);
+			return new SphericalSurface(toSphere, usedArea);
 		}
 		/// <summary>
 		/// Overrides <see cref="CADability.GeoObject.ISurfaceImpl.Modify (ModOp)"/>