[geos-devel] Ownership of userData

[Paul Ramsey]

I am going through the various tickets and PRs and trying to clean
them up. This one seemed straightforward at first, but the issue of
ownership of userData is pretty ugly in GEOS land.

https://github.com/libgeos/geos/pull/115#issuecomment-458649362

Basically we seem to currently assume that whomever assigned userData
will clean up said userData. But in the case of this ticket, the GEOS
engine itself is assigning it. I think we just cannot do that. It's
not userData any more, it's geosData, and users cannot be expected to
clean it up.

We could further enhance geometry to also have geosData, maybe
something like a python dictionary of extra "stuff" that can be added
to geometry optionally, but in the short term I'd rather just not
follow the contract of including the cell coordinates in the returned
voronoi polygons.

P