--- /dev/null
+## Copyright (C) 2014-2017 CEA/DEN, EDF R&D
+##
+## This library is free software; you can redistribute it and/or
+## modify it under the terms of the GNU Lesser General Public
+## License as published by the Free Software Foundation; either
+## version 2.1 of the License, or (at your option) any later version.
+##
+## This library is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+## Lesser General Public License for more details.
+##
+## You should have received a copy of the GNU Lesser General Public
+## License along with this library; if not, write to the Free Software
+## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+##
+## See http:##www.salome-platform.org/ or
+## email : webmaster.salome@opencascade.com<mailto:webmaster.salome@opencascade.com>
+##
+
+from salome.shaper import model
+
+model.begin()
+partSet = model.moduleDocument()
+Sketch_1 = model.addSketch(partSet, model.defaultPlane("XOZ"))
+SketchLine_1 = Sketch_1.addLine(10, 10, 10, 100)
+SketchLine_2 = Sketch_1.addLine(10, 100, 100, 10)
+SketchConstraintCoincidence_1 = Sketch_1.setCoincident(SketchLine_1.endPoint(), SketchLine_2.startPoint())
+model.do()
+# make non-perpendicular line perpendicular
+SketchConstraintPerpendicular_1 = Sketch_1.setPerpendicular(SketchLine_1.result(), SketchLine_2.result())
+model.do()
+# this moves the line
+assert(SketchLine_1.startPoint().x() != 10)
+model.end()
+model.undo()
+# undo must move the line exactly back
+assert(SketchLine_1.startPoint().x() == 10)