[postgis-devel] ALTER EXTENSION postgis UPGRADE to '2.1.1'

[Paul Ramsey]

This has been failing for people using packages to manage their
postgis, because upgrading their postgis2 package is removing the old
postgis-2.0.so and installing a postgis-2.1.so file.

I isolated the problem while on the plane, it's the temporary
postgis_major_version_check function, which calls a library function
during installation. I think it'll take a half day of careful thinking
and testing to get a fix that both works on existing installations and
also does the right thing, which I think is to get rid of that routine
entirely. It's very old and pre-dates extensions, and we don't have an
upgrade_15_21 script anyways. We can add a replacement in 10 years
when we do 3.0

P.