ui: Remove virtual nodes in depth graph edges when moving nodes (issue #639)

src/lib_gui/qt/view/graphElements/QtGraphEdge.cpp

@@ -492,3 +492,8 @@ void QtGraphEdge::setUseBezier(bool useBezier)
 	m_useBezier = useBezier;
 	m_isHorizontal = true;
 }
+
+void QtGraphEdge::clearPath()
+{
+	m_path.clear();
+}

src/lib_gui/qt/view/graphElements/QtGraphEdge.h

@@ -58,6 +58,7 @@ public:
 	void setIsTrailEdge(std::vector<Vec4i> path, bool horizontal);
 
 	void setUseBezier(bool useBezier);
+	void clearPath();
 
 protected:
 	virtual void mousePressEvent(QGraphicsSceneMouseEvent* event);

src/lib_gui/qt/view/graphElements/QtGraphNode.cpp

@@ -506,6 +506,7 @@ void QtGraphNode::notifyEdgesAfterMove()
 	forEachEdge(
 		[](QtGraphEdge* edge)
 		{
+			edge->clearPath();
 			edge->updateLine();
 		}
 	);