SRID of geography is lost during ST_Buffer(geography..) operation

[robe]

I tested this on a PostGIS 3.1.7 RDS system as well as my POSTGIS="3.3.2 3.3.2" [EXTENSION] PGSQL="150" GEOS="3.11.1-CAPI-1.17.1" PROJ="7.2.1" LIBXML="2.9.9" LIBJSON="0.12" LIBPROTOBUF="1.2.1" WAGYU="0.5.0 (Internal)"

and the behavior is the same:

SELECT ST_SRID( ST_Buffer(ST_GeomFromText('POINT(-94 29.53)', 4269)::geography, 12)::geometry )

The answer here is 4326 instead of the expected 4269. This works fine

SELECT ST_SRID(ST_GeomFromText('POINT(-94 29.53)', 4269)::geography::geometry)

the SRID returned is 4269, so seems to be something going on in the ST_Buffer geography function that is losing the original SRID

[darkblueb]

osgeolive ol16 alpha returns 4326

 POSTGIS="3.3.2 4975da8" [EXTENSION] PGSQL="140" GEOS="3.11.1-CAPI-1.17.1" PROJ="9.1.1" LIBXML="2.9.13" LIBJSON="0.15" LIBPROTOBUF="1.3.3" WAGYU="0.5.0 (Internal)"

[Paul Ramsey <pramsey@…>]

In bef103b/git:

Preserve input SRID in SQL wrapper to synthetic buffer, closes #5378

[robe]

I think we need to backport this fix to at least PostGIS 3.3.3. Given the amount of changes, not sure it makes sense to backport any further than that. I'll close this out once I've backported.

[Paul Ramsey <pramsey@…>]

In 15a1827/git:

Retain SRID through ST_Buffer(geography) call, references #5378

[Paul Ramsey <pramsey@…>]

In 36b162b/git:

Retain SRID through ST_Buffer(geography) call, references #5378

[robe]

Now all we need is a test and then we can close this out

[robe]

Added test for 3.2.4 at [4a97397ea5d0b9a77b13f58f69c7b2d3b3961ba4/git]

[Regina Obe <lr@…>]

In c5f2076/git:

Add test for PostGIS 3.3.3
References #5378

[Regina Obe <lr@…>]

In 0919b134/git:

Add test for PostGIS 3.4.0
Closes #5378