[OSM-talk] Help with reverting a changeset (somebody deleted weeks and weeks of work)

[Andy Townsend]

On 09/04/2023 12:55, Bjoern Hassler wrote:
> Hello everybody!
>
> I hope you're having a good weekend. I'm looking for help with 
> reverting a changeset 
> https://www.openstreetmap.org/changeset/54488428?way_page=6#map=14/51.5273/-0.1224. 
> (Kings Cross, London)
>
> The changeset is labeled "Large correction of outdated information", 
> and while the 'correction' was large, the information wasn't outdated 
> at all. The editor mistook an extensive set underground paths (labeled 
> correctly with level, leading to underground railways) for obsolete 
> footpaths and stripped them all out - removing the entire underground 
> structure. They hadn't noticed that the same user (me, bjohas) had put 
> them all in only a year or so earlier (which took me weeks and weeks 
> to do, sigh).
>
> Obviously a few edits have happened since, but the underground 
> footpaths haven't been restored/re-added. I'd like to 'cautiously' 
> revert/merge those edits. However, it does involve many many paths, 
> nodes etc etc. While I'm a fairly experienced mapper / josm user 
> (https://www.openstreetmap.org/user/bjohas), I feel that I'd best do 
> this with support from somebody, to make sure that the initial 
> destruction doesn't lead to more destruction...
>
>
Given that it's 5 years ago that these were deleted, you're not going to 
be able to do a simple revert.

What you could do is, where particular things are still missing, 
"undelete" the deleted paths one by one and then join up to any current 
features (checking for problems with the JOSM validator as you go).

For "undelete" functionality you could use JOSM's "undelete" plugin or 
the perl revert scripts' "undo.pl".  There may be other options too.

You're going to have to do it one object at a time anyway, so perhaps do 
a couple first and then ask again to see if anyone can see any problems 
with what you've done?

Best Regards,

Andy