[TD]fix uncommanded leader position change

src/Mod/TechDraw/Gui/QGILeaderLine.h

@@ -73,6 +73,9 @@ public:
     void drawBorder() override;
     void updateView(bool update = false) override;
 
+    // leaders are not draggable
+    void dragFinished() override { };
+
     virtual TechDraw::DrawLeaderLine* getLeaderFeature();
 
     void startPathEdit();

src/Mod/TechDraw/Gui/QGIView.cpp

@@ -228,6 +228,10 @@ QVariant QGIView::itemChange(GraphicsItemChange change, const QVariant &value)
 
     return QGraphicsItemGroup::itemChange(change, value);
 }
+
+//! The default behaviour here only applies to views whose (X, Y) describes a position on the page.
+//! Others, like QGILeaderLine whose (X, Y) describes a position within a view's boundary and is not
+//! draggable, should override this method.
 void QGIView::dragFinished()
 {
     if (!viewObj) {

src/Mod/TechDraw/Gui/QGIView.h

@@ -178,7 +178,7 @@ protected:
     QGIView* getQGIVByName(std::string name) const;
 
     QVariant itemChange(GraphicsItemChange change, const QVariant &value) override;
-    void dragFinished();
+    virtual void dragFinished();
 
     // Preselection events:
     void hoverEnterEvent(QGraphicsSceneHoverEvent *event) override;