From aa410adae884fd5448a5ac94d321cf264e489a91 Mon Sep 17 00:00:00 2001
From: azv <azv@opencascade.com>
Date: Wed, 29 Mar 2017 13:56:21 +0300
Subject: [PATCH] Issue #2058: Fatal error when create split constraint

Fix wrong processing of tangent constraint between line and circle having one coincident point.
---
 src/SketchSolver/SketchSolver_ConstraintTangent.cpp | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/SketchSolver/SketchSolver_ConstraintTangent.cpp b/src/SketchSolver/SketchSolver_ConstraintTangent.cpp
index 709d09185..1c42ac69a 100644
--- a/src/SketchSolver/SketchSolver_ConstraintTangent.cpp
+++ b/src/SketchSolver/SketchSolver_ConstraintTangent.cpp
@@ -307,12 +307,13 @@ ConstraintWrapperPtr createArcLineTangency(EntityWrapperPtr theEntity1,
 
   std::shared_ptr<GCS::Circle> aCirc =
       std::dynamic_pointer_cast<GCS::Circle>(anEntCirc->entity());
+  std::shared_ptr<GCS::Arc> anArc = std::dynamic_pointer_cast<GCS::Arc>(aCirc);
+
   std::shared_ptr<GCS::Line> aLine =
       std::dynamic_pointer_cast<GCS::Line>(anEntLine->entity());
 
   GCSConstraintPtr aNewConstr;
-  if (theSharedPoint) {
-    std::shared_ptr<GCS::Arc> anArc = std::dynamic_pointer_cast<GCS::Arc>(aCirc);
+  if (theSharedPoint && anArc) { // do not process shared point between circle and line
     GCSPointPtr aPoint =
         std::dynamic_pointer_cast<PlaneGCSSolver_PointWrapper>(theSharedPoint)->point();
 
-- 
2.39.2