[postgis-devel] liblwgeom symbols exported by postgis module

[Paragon Corporation]

>> I want to make sure the PostGIS 2.2.0 is not fed by liblwgeom... 
>> distributed by PostGIS 2.3.0  because that would introduce possibly 
>> breaking changes or enhancements the user does not want.

> Oh, I see now. And I correct myself saying that liblwgeom SONAME is really
only defined by the Major version, excluding Minor, so a dynamically-linked
2.2.0 would be indeed served by the liblwgeom version shipped with 2.3.0. 

> Breaking changes we should not introduce if not changing the Major version
of the liblwgeom library. Of course this might mean separating versioning of
liblwgeom from versioning of PostGIS.

> Or, we include Minor in the SONAME of liblwgeom, but then would you be ok
with 2.2.0 being fed by liblwgeom distributed by 2.2.1 ?

> --strk;


Yes 2.2.0 being fed by 2.2.1 is fine and expected.  2.2.1 being fed by 2.3.0
is not.


Our minor releases are just as major as PostgreSQL releases with the
exception that you don't need to do a dump/restore or pg_upgrade to use
them.  But they have internal things even within the liblwgeom lib that I'd
feel uncomfortable pushing on someone expecting say a 2.2.1.

Not to mention -- if someone complains about an issue -- then we need to ask
are they using liblwgeom shipped with 2.3.0 on a 2.2.1 install.  We don't
even release these things necessarily in sequence like PostgreSQL group
does.

e.g.

Our PostGIS 2.1.9 release might have bug fixes in the liblwgeom not in
PostGIS 2.2.0.  So which liblwgeom do you use -- the one in the 2.2 trunk or
2.1 trunk?

So our liblwgeom versioning should ideally follow our minor versioning as I
had originally asked for.

I thought we didn't go with that because sometimes the liblwgeom API may
change between 2.2.0 to 2.2.1 for some reason (like an internal need that
doesn't change the PostGIS SQL API).  In that case we'd have to have a
liblwgeom-3.so to go with 2.2.1,
But normally liblwgeom-2.so would always be what you get with 2.2.x


Thanks,
Regina