Merge pull request #1435 from bhangart/fix/line-pivot-follows-resize

Keep a line's pivot at its centre when one of its ends is dragged

sources/qetgraphicsitem/qetshapeitem.cpp

@@ -2465,6 +2465,10 @@ void QetShapeItem::dragResize(int index, const QPointF &localPos, Qt::KeyboardMo
 	{
 		prepareGeometryChange();
 		(index == 0 ? m_P1 : m_P2) = localPos;
+		// The same rule as setLine() and setRect(): a pivot nobody placed
+		// by hand follows the centre.
+		if (!m_pivotIsCustom)
+			resetPivotToBoundingRectCenter();
 		repositionHandles();
 		emit geometryChanged();
 		return;