Cannot upgrade: cannot drop function st_summarystats(raster,integer,boolean) because other objects depend on it

[strk]

I cannot upgrade an extension from 2.2.0dev to 2.2.0devnext due to this:

 cannot drop function st_summarystats(raster,integer,boolean) because other objects depend on it

[strk]

These two lines are found in rtpostgis_upgrade_cleanup.sql:

-- remove TYPE summarystats
DROP FUNCTION IF EXISTS st_summarystats(raster,int, boolean);

The datatype was removed as part of #1939

[strk]

Alright, the return datatype changed, which is the reason why the function is dropped. BUT, we should make the drop dependent on source version, driven by postgis_proc_upgrade.pl.

When a function signature changed in an way that is not compatible with "CREATE OR REPLACE FUNCTION", we should note it with a "Last Something" documenting the incompatibility.

See also #2722

[strk]

The function signature changed with version 2.1.0 so there's no reason to drop it when going from 2.2.0dev to 2.2.0devnext

[strk]

I can't reproduce this anymore, so will assume fixed.