Fix the problem is tangent segments are not intersected.

diff --git a/src/SketcherPrs/SketcherPrs_Tangent.cpp b/src/SketcherPrs/SketcherPrs_Tangent.cpp
index 70c96ac102f1c7965a87f81425df625e2316e7ac..bf998d8120b5e8fe1c17ed3d932ab56567ee012c 100644 (file)
--- a/src/SketcherPrs/SketcherPrs_Tangent.cpp
+++ b/src/SketcherPrs/SketcherPrs_Tangent.cpp
@@ -80,7 +80,7 @@ bool SketcherPrs_Tangent::updateIfReadyToDisplay(double theStep, bool withColor)
 
   GeomPointPtr aPnt;
   GeomShapePtr aIntPnt = aShp1->intersect(aShp2);
-  if (aIntPnt->isVertex()) {
+  if (aIntPnt.get() && aIntPnt->isVertex()) {
     GeomVertexPtr aVetrex(new GeomAPI_Vertex(aIntPnt));
     aPnt = aVetrex->point();
   }