[OSM-talk] Mappers and apps should focus on relations at the very start

[Paul Norman]

On 6/27/2015 1:14 PM, Fernando Trebien wrote:
> Actually no, the server checks for circular dependencies, and a
> relation pointing to itself is a cycle. Try it, the server returns a
> validation error.
Nothing in the OSM data model prohibits a relation that references 
itself, or relations that form a cycle.

As an example, see https://www.openstreetmap.org/relation/1368401 which 
contains itself twice. Longer cycles are also possible.

I can't imagine a case where a cycle is sensible, and they are often 
difficult to delete, first requiring modifying the relations to remove 
the cycle, then deleting the relations.