From 81c88369b8540565fb46c0ff9b790c669ed9491b Mon Sep 17 00:00:00 2001
From: azv <azv@opencascade.com>
Date: Tue, 23 May 2017 13:03:10 +0300
Subject: [PATCH] Issue #1918: Unable to create a tangent arc.

Fix crash on tangent arc with infinite radius.
---
 src/SketchPlugin/SketchPlugin_MacroArc.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/SketchPlugin/SketchPlugin_MacroArc.cpp b/src/SketchPlugin/SketchPlugin_MacroArc.cpp
index 5bbb32235..60c0360d3 100644
--- a/src/SketchPlugin/SketchPlugin_MacroArc.cpp
+++ b/src/SketchPlugin/SketchPlugin_MacroArc.cpp
@@ -618,6 +618,8 @@ void SketchPlugin_MacroArc::fillByTangentEdge()
   aCircBuilder.addTangentCurve(aTangentShape);
 
   std::shared_ptr<GeomAPI_Circ2d> aCircle = aCircBuilder.circle();
+  if (!aCircle)
+    return;
   myCenter = aCircle->center();
 
   // rebuild circle to set start point equal to zero parameter
-- 
2.39.2