role reversed during combine remains reversed upon canceling/undoing

[NE2]

Create two ways that begin at a common point, tag them oneway=yes, and add them to a relation with role forward. Combine them, clicking 'reverse and combine' and then 'apply selected changes', but then cancel the last window. Open the relation, and note that the way that was reversed now has role=backward, even though it is back to oneway=yes and no command appears in the stack.

This also happens if you apply at the last window and then undo. It does not happen if the way that is reversed does not have a tag that also gets reversed (here the oneway=yes).

[simon04]

In 9439/josm:

fix #8041 - Relation change bypassing undo system during combine way