From 19f77300a8c551a093c1a5e3d4089379ddab3754 Mon Sep 17 00:00:00 2001
From: jgv <jgv@opencascade.com>
Date: Wed, 14 Oct 2020 11:54:11 +0300
Subject: [PATCH] Fix of regression in Extrema, improvement in 3D offset.

---
 src/BRepOffset/BRepOffset_Tool.cxx | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/BRepOffset/BRepOffset_Tool.cxx b/src/BRepOffset/BRepOffset_Tool.cxx
index af3ac106e1..fb324f8e10 100644
--- a/src/BRepOffset/BRepOffset_Tool.cxx
+++ b/src/BRepOffset/BRepOffset_Tool.cxx
@@ -3115,12 +3115,23 @@ Standard_Boolean BRepOffset_Tool::EnLargeFace
   }
   else
   {
-    Standard_Real FaceDU = UF2 - UF1;
-    Standard_Real FaceDV = VF2 - VF1;
-    UU1 = UF1 - 10*FaceDU;
-    UU2 = UF2 + 10*FaceDU;
-    VV1 = VF1 - 10*FaceDV;
-    VV2 = VF2 + 10*FaceDV;
+    if (theExtensionMode == 2)
+    {
+      Standard_Real FaceDU = UF2 - UF1;
+      Standard_Real FaceDV = VF2 - VF1;
+      UU1 = UF1 - 10*FaceDU;
+      UU2 = UF2 + 10*FaceDU;
+      VV1 = VF1 - 10*FaceDV;
+      VV2 = VF2 + 10*FaceDV;
+    }
+    else
+    {
+      Standard_Real aSize = theLenBeforeUfirst;
+      UU1 = UF1 - aSize;
+      UU2 = UF2 + aSize;
+      VV1 = VF1 - aSize;
+      VV2 = VF2 + aSize;
+    }
     coeff = 1.;
   }
   
-- 
2.39.5