Created attachment 150750 [details]
A user defined shape to see the wrong behavior

Open attached document in PowerPoint. It has a shape with a custGeom, where the path has got w and h attribute, which defines a local coordinate system (a 'viewBox'). The shape has a handle. Drag it to verify that it works.

Open the document in LibreOffice. Notice, that the handle marker is not at the corner of the triangle. Drag the handle. The triangle changes as expected. Release the handle. Notice, that the handle is not shown where you have released it, but at a place left from it.

The reason is, that when LO gets the handle position from the shape, it applies the scaling again, which is needed for fitting the outer to the inner coordinate, although the value of the handle position is already scaled in case of OOXML-shapes.

The "cloudCallout" is the only shape from the preset, that uses a path coordinate system. But because of bug 115813 you cannot use it, for testing this bug.