[josm-dev] Another 66 relations bite the dust

[Matthias Julius]

Sebastian Klein <bastikln at googlemail.com> writes:

> Roland Olbricht wrote:
>>> [1] http://trac.openstreetmap.org/ticket/2652
>> 
>> You can get an approximate solution: 
>> http://78.46.81.38/api/rels-extended?id=34631 This points to the
>> OSM3S server and returns the desired relation-ids for the given
>> relation id.
>
>> But still this would be a great step from deleting relations
>> accidentally.
>
> No, this particular problem generally does *not* cause accidental
> deletion of relations!
>
> The worst that can happen is someone splits a way and does not add the
> new part into the relation (because he does not know about it). Then a
> multipolygon is no longer closed and does not render ... something like
> that.
>
> Also, if the user operates inside the downloaded bbox, everything is
> fine. The issue comes into play when editing boundaries and other large
> scale objects.

A while ago I was toying with the idea of having JOSM track for each
primitive whether or not it knows about its parents.  AFAICT it should
only know with some certainty if the primitive was downloaded inside the
bounding box of a map call or if it has asked the API explicitly.  Then
it could show a message like:

This object might have parents that have not been downloaded from the
server and that might be affected by this operation. How do you want to
proceed?

<Cancel>  <Ignore>  <Download parents>

Optionally JOSM could also check the server automatically for parents.

Matthias