From: Michael Paquier <michael@paquier.xyz>
Date: Wed, 20 Jan 2021 02:39:24 +0000 (+0900)
Subject: Fix ALTER DEFAULT PRIVILEGES with duplicated objects
X-Git-Tag: REL_10_16~21
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=74ee3abcfefa6e6b0756f85baa31a7ae21bb2fec;p=postgresql.git

Fix ALTER DEFAULT PRIVILEGES with duplicated objects

Specifying duplicated objects in this command would lead to unique
constraint violations in pg_default_acl or "tuple already updated by
self" errors.  Similarly to GRANT/REVOKE, increment the command ID after
each subcommand processing to allow this case to work transparently.

A regression test is added by tweaking one of the existing queries of
privileges.sql to stress this case.

Reported-by: Andrus
Author: Michael Paquier
Reviewed-by: Álvaro Herrera
Discussion: https://postgr.es/m/ae2a7dc1-9d71-8cba-3bb9-e4cb7eb1f44e@hot.ee
Backpatch-through: 9.5
---

diff --git a/src/backend/catalog/aclchk.c b/src/backend/catalog/aclchk.c
index 13785add07f..4befcb797dd 100644
--- a/src/backend/catalog/aclchk.c
+++ b/src/backend/catalog/aclchk.c
@@ -1328,6 +1328,9 @@ SetDefaultACL(InternalDefaultACL *iacls)
 		ReleaseSysCache(tuple);
 
 	heap_close(rel, RowExclusiveLock);
+
+	/* prevent error when processing duplicate objects */
+	CommandCounterIncrement();
 }
 
 
diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out
index 46f11c241ff..ada059244ac 100644
--- a/src/test/regress/expected/privileges.out
+++ b/src/test/regress/expected/privileges.out
@@ -1581,7 +1581,8 @@ SELECT has_table_privilege('regress_user1', 'testns.acltest1', 'INSERT'); -- no
  f
 (1 row)
 
-ALTER DEFAULT PRIVILEGES IN SCHEMA testns GRANT SELECT ON TABLES TO public;
+-- placeholder for test with duplicated schema and role names
+ALTER DEFAULT PRIVILEGES IN SCHEMA testns,testns GRANT SELECT ON TABLES TO public,public;
 SELECT has_table_privilege('regress_user1', 'testns.acltest1', 'SELECT'); -- no
  has_table_privilege 
 ---------------------
diff --git a/src/test/regress/sql/privileges.sql b/src/test/regress/sql/privileges.sql
index 968704a8f55..7edfc28f845 100644
--- a/src/test/regress/sql/privileges.sql
+++ b/src/test/regress/sql/privileges.sql
@@ -942,7 +942,8 @@ CREATE TABLE testns.acltest1 (x int);
 SELECT has_table_privilege('regress_user1', 'testns.acltest1', 'SELECT'); -- no
 SELECT has_table_privilege('regress_user1', 'testns.acltest1', 'INSERT'); -- no
 
-ALTER DEFAULT PRIVILEGES IN SCHEMA testns GRANT SELECT ON TABLES TO public;
+-- placeholder for test with duplicated schema and role names
+ALTER DEFAULT PRIVILEGES IN SCHEMA testns,testns GRANT SELECT ON TABLES TO public,public;
 
 SELECT has_table_privilege('regress_user1', 'testns.acltest1', 'SELECT'); -- no
 SELECT has_table_privilege('regress_user1', 'testns.acltest1', 'INSERT'); -- no