Use @extschema:name@ notation in contrib transform modules.

Harden hstore_plperl, hstore_plpython, and ltree_plpython
against search-path-based attacks by using @extschema:name@
notation to refer to the underlying hstore or ltree data type.

This allows removal of the previous documentation warning
suggesting that they must be installed in the same schema as
the underlying data type.  In passing, also improve a para in
extend.sgml to suggest using @extschema:name@ for such purposes.

Discussion: https://postgr.es/m/692480.1736021695@sss.pgh.pa.us

1 files changed, 3 insertions, 3 deletions

diff --git a/contrib/hstore_plpython/hstore_plpython3u--1.0.sql b/contrib/hstore_plpython/hstore_plpython3u--1.0.sql
index 0b410ab1835..35082322416 100644
--- a/contrib/hstore_plpython/hstore_plpython3u--1.0.sql
+++ b/contrib/hstore_plpython/hstore_plpython3u--1.0.sql
@@ -7,13 +7,13 @@ CREATE FUNCTION hstore_to_plpython3(val internal) RETURNS internal
 LANGUAGE C STRICT IMMUTABLE
 AS 'MODULE_PATHNAME', 'hstore_to_plpython';
 
-CREATE FUNCTION plpython3_to_hstore(val internal) RETURNS hstore
+CREATE FUNCTION plpython3_to_hstore(val internal) RETURNS @extschema:hstore@.hstore
 LANGUAGE C STRICT IMMUTABLE
 AS 'MODULE_PATHNAME', 'plpython_to_hstore';
 
-CREATE TRANSFORM FOR hstore LANGUAGE plpython3u (
+CREATE TRANSFORM FOR @extschema:hstore@.hstore LANGUAGE plpython3u (
     FROM SQL WITH FUNCTION hstore_to_plpython3(internal),
     TO SQL WITH FUNCTION plpython3_to_hstore(internal)
 );
 
-COMMENT ON TRANSFORM FOR hstore LANGUAGE plpython3u IS 'transform between hstore and Python dict';
+COMMENT ON TRANSFORM FOR @extschema:hstore@.hstore LANGUAGE plpython3u IS 'transform between hstore and Python dict';