Allow GRANTED BY clause in normal GRANT and REVOKE statements

The SQL standard allows a GRANTED BY clause on GRANT and
REVOKE (privilege) statements that can specify CURRENT_USER or
CURRENT_ROLE.  In PostgreSQL, both of these are the default behavior.
Since we already have all the parsing support for this for the
GRANT (role) statement, we might as well add basic support for this
for the privilege variant as well.  This allows us to check off SQL
feature T332.  In the future, perhaps more interesting things could be
done with this, too.

Reviewed-by: Simon Riggs <simon@2ndquadrant.com>
Discussion: https://www.postgresql.org/message-id/flat/f2feac44-b4c5-f38f-3699-2851d6a76dc9@2ndquadrant.com

2 files changed, 8 insertions, 4 deletions

diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out
index 8f2fc89851b..ed98fa8376f 100644
--- a/src/test/regress/expected/privileges.out
+++ b/src/test/regress/expected/privileges.out
@@ -70,8 +70,10 @@ SELECT * FROM atest1;
 CREATE TABLE atest2 (col1 varchar(10), col2 boolean);
 GRANT SELECT ON atest2 TO regress_priv_user2;
 GRANT UPDATE ON atest2 TO regress_priv_user3;
-GRANT INSERT ON atest2 TO regress_priv_user4;
-GRANT TRUNCATE ON atest2 TO regress_priv_user5;
+GRANT INSERT ON atest2 TO regress_priv_user4 GRANTED BY CURRENT_USER;
+GRANT TRUNCATE ON atest2 TO regress_priv_user5 GRANTED BY CURRENT_ROLE;
+GRANT TRUNCATE ON atest2 TO regress_priv_user4 GRANTED BY regress_priv_user5;  -- error
+ERROR:  grantor must be current user
 SET SESSION AUTHORIZATION regress_priv_user2;
 SELECT session_user, current_user;
     session_user    |    current_user    
diff --git a/src/test/regress/sql/privileges.sql b/src/test/regress/sql/privileges.sql
index 1c250a11fe1..becbc196713 100644
--- a/src/test/regress/sql/privileges.sql
+++ b/src/test/regress/sql/privileges.sql
@@ -64,8 +64,10 @@ SELECT * FROM atest1;
 CREATE TABLE atest2 (col1 varchar(10), col2 boolean);
 GRANT SELECT ON atest2 TO regress_priv_user2;
 GRANT UPDATE ON atest2 TO regress_priv_user3;
-GRANT INSERT ON atest2 TO regress_priv_user4;
-GRANT TRUNCATE ON atest2 TO regress_priv_user5;
+GRANT INSERT ON atest2 TO regress_priv_user4 GRANTED BY CURRENT_USER;
+GRANT TRUNCATE ON atest2 TO regress_priv_user5 GRANTED BY CURRENT_ROLE;
+
+GRANT TRUNCATE ON atest2 TO regress_priv_user4 GRANTED BY regress_priv_user5;  -- error
 
 
 SET SESSION AUTHORIZATION regress_priv_user2;