Fix visualization for tool point of intersection line and axis. Case when the axis's point lies on the line.

ChangeLog.txt

@@ -6,6 +6,7 @@
 - [smart-pattern/valentina#136] 2 decimals for entering values in multi measurements tables.
 - New warnings. Warn a user about incorrect cut curve segment length.
 - Fix finding point of intersection curve and axis. Case when the axis's point lies on the curve.
+- Fix visualization for tool point of intersection line and axis. Case when the axis's point lies on the line.
 
 # Valentina 0.7.49 July 1, 2021
 - Fix crash.

src/libs/vtools/visualization/line/vistoollineintersectaxis.cpp

@@ -99,7 +99,10 @@ void VisToolLineIntersectAxis::RefreshGeometry()
                 QPointF p;
                 VToolLineIntersectAxis::FindPoint(axis, base_line, &p);
                 QLineF axis_line(static_cast<QPointF>(*third), p);
-                DrawLine(this, axis_line, mainColor, lineStyle);
+                if (not axis_line.isNull())
+                {
+                    DrawLine(this, axis_line, mainColor, lineStyle);
+                }
 
                 DrawPoint(point, p, mainColor);
                 ShowIntersection(axis_line, base_line);