From c5b89fa358ab0932d7edb54af82b86bb4164dd5c Mon Sep 17 00:00:00 2001
From: aml <aml@opencascade.com>
Date: Fri, 10 Nov 2017 18:21:21 +0300
Subject: [PATCH] 0025879: result of blend fails the bopcheck

Protection from the zero-length gp_Dir construction is added.
---
 src/ElCLib/ElCLib.cxx        | 6 ++++--
 tests/bugs/modalg_7/bug25879 | 2 --
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/ElCLib/ElCLib.cxx b/src/ElCLib/ElCLib.cxx
index 8801ef8a3b..c16bb6c7dd 100644
--- a/src/ElCLib/ElCLib.cxx
+++ b/src/ElCLib/ElCLib.cxx
@@ -1312,8 +1312,10 @@ Standard_Real ElCLib::LineParameter (const gp_Ax1& L, const gp_Pnt& P)
 Standard_Real ElCLib::CircleParameter (const gp_Ax2& Pos,
 				       const gp_Pnt& P)
 {
-  Standard_Real Teta = (Pos.XDirection()) .AngleWithRef
-    (gp_Vec (Pos.Location(), P), Pos.Direction());
+  gp_Vec aVec(Pos.Location(), P);
+  Standard_Real Teta = 0.0;
+  if (aVec.SquareMagnitude() > gp::Resolution())
+    Teta = (Pos.XDirection()).AngleWithRef(aVec, Pos.Direction());
   if      (Teta < -1.e-16)  Teta += PIPI;
   else if (Teta < 0)        Teta = 0;
   return Teta;
diff --git a/tests/bugs/modalg_7/bug25879 b/tests/bugs/modalg_7/bug25879
index e344c396ab..77ec001125 100755
--- a/tests/bugs/modalg_7/bug25879
+++ b/tests/bugs/modalg_7/bug25879
@@ -1,5 +1,3 @@
-puts "TODO OCC25879 Windows: Error : result of blend fails the bopcheck"
-
 puts "============"
 puts "OCC25879"
 puts "============"