[postgis-devel] EXTENSION upgrade scripts are now symlinks

[Sandro Santilli]

On Fri, Oct 06, 2017 at 05:54:50AM -0700, Paul Ramsey wrote:
> Once you're at 'next' there's nowhere to go. You end up with having to
> upgrade from 'next' to 'next2' and so on :)

You might have misse ths part:

> > And then the script would re-set pg_extension version
> > to drop the "next" and keep the "final".

Basically he upgrade script would change the extension version
to NOT be "next" anymore, but the label from which we start,
so that every UPDATE would go from (example) "stable" to "next"
and the record in pg_extension would be marked as being "stable"
again afterwards.

NOTE: I didn't try this, dunno if the PostgreSQL people added
some protection against similar hacks.

--strk;