Allow merging line with no tags with multipolygons

[arch0345]

Description

While #8675 in v2.20.2 helps prevent relations from being damaged, it has made it more difficult for me to clean up multipolygon areas sharing the same sides, such as here:

Is it possible to enable the merge operation when merging a line with one that doesn't have any tags or affiliated with any relations, like shown below? As you can see in the image above, I removed the residential area relation from the way selected in the other image and am trying to merge another way in that same residential area with a line I created parallel to the one selected in the other image that has no tags or memberships in any relations.

[DujaOSM]

Try as I may, I cannot understand what you are trying to do. Your screenshot only shows one line selected, and it's unclear what you are trying to merge it with.

[arch0345]

Try as I may, I cannot understand what you are trying to do. Your screenshot only shows one line selected, and it's unclear what you are trying to merge it with.

Thanks for letting me know - I've added another screenshot with an explanation. Let me know if this needs any further clarification.

[1ec5]

Is it possible to enable the merge operation when merging a line with one that doesn't have any tags or affiliated with any relations, like shown below?

That would involve making an exception here, which would be straightforward:

https://github.com/openstreetmap/iD/blob/1457759994c91b2a65922d6bfa478504355e65be/modules/actions/join.js#L145-L147

However, note that #8645 was fixed specifically by disallowing merging with a nonmember way, which can inadvertently introduce a branch in a route relation or a degenerate multipolygon or boundary. Ideally, iD would distinguish the case where the relation was already broken and needs fixing, which may be feasible with some types of relations but more difficult with others (like boundaries: #8286).

As a workaround, you can manually add the nonmember way to the relation.

[rivermont]

(Error is 'These features can't be merged because they belong to conflicting relations' for searchability)

[jjiglesiasg]

I guess this should be the same, I tried to merge a line with a waterway and shows me this message, depite the line have No tags or other values

[sekerob]

Absolutely and totally NNnd this request, severely slowed down the complex mapping I'm doing. Map a line to enlarge an area and first the tag(s) need adding and 9 out of 10 if more than 1 area relation is involved the merge is rejected, then having to remove all but one, merge the line and add the relation tags back. If a tagless line is merged with a tagged line you're 100% sure the correct areas/tags are proliferated, Picture having multiple zones in the area of the same... farmland e.g. Before you know it you pick the wrong one. Goes for areas and highways. Oddly, a single closed tagless line can be merged with any area relation, by shift selecting an existing area, right clicking and hitting the plus sign, Anyway, 2.20.2 sped up work, then took 2 steps back, for me, with removing the select-lines merge feature.