Webplanner - Undo/Redo goes wrong after deleting the last point added

Example:

Create route by adding e.g. 4 points.

Delete point 4 by using the itinerary or right click the point and delete it.

Expected : The undo button appears and is enabled, and the redo button appears and is disabled.

Actual: Both undo and redo buttons appear and both are enabled.

Click on Undo.

Expected : Point 4 is re-added (i.e. it undos the last action)

Actual : Point 3 is deleted.

If instead of clicking Undo you click Redo then Point 4 is re-added.

This not how undo/redo usually works. e.g compare with LM android which behaves correctly.

Usually performing an action adds the reverse action to the Undos , and clears the Redos. Redos can only reverse a previous undo, not a user action.

If you add a point in the middle of the route either using the itinerary, or dragging the route marker, then delete that point, the same issue happens.

However if you do the above after doing an undo then redo then it does not happen.

e.g. add 4 points , do undo then redo then delete point 4: only the undo button is enabled, and clicking it does re-add the point.