Tools>create Multipolygon should add ways to existing multipolygon
I can use create multipolygon to automatically create a multipolygon relation and assign the proper roles. However, if there already is a multipolygon relation, I have to manually add any new members, like forest clearings and assign their role. If I re-run the create multipolygon action, I end up with 2 relations.
Expected result: if one of the selected ways is already member of a multipolygon relation, try to add the other selected ways to that relation if possible, otherwise display an error message.
It should be really simple, because all inner-outer logic is identical, it just needs to use the existing relation and prevent duplicated members.