Fix cache reference leak in contrib/sepgsql.

fixup_whole_row_references() did the wrong thing with a dropped column,
resulting in a commit-time warning about a cache reference leak.

I (tgl) added a test case exercising this, but back-patched the test
only as far as v10; the patch didn't apply cleanly to 9.6 and it
didn't seem worth the trouble to adapt it.  The bug is pretty old
though, so apply the code change all the way back.

Michael Luo, with cosmetic improvements by me

Discussion: https://postgr.es/m/BYAPR08MB5606D1453D7F50E2AF4D2FD29AD80@BYAPR08MB5606.namprd08.prod.outlook.com

1 files changed, 14 insertions, 2 deletions

diff --git a/contrib/sepgsql/expected/dml.out b/contrib/sepgsql/expected/dml.out
index 31243c723b..6d5b1c1903 100644
--- a/contrib/sepgsql/expected/dml.out
+++ b/contrib/sepgsql/expected/dml.out
@@ -4,8 +4,9 @@
 --
 -- Setup
 --
-CREATE TABLE t1 (a int, b text);
+CREATE TABLE t1 (a int, junk int, b text);
 SECURITY LABEL ON TABLE t1 IS 'system_u:object_r:sepgsql_table_t:s0';
+ALTER TABLE t1 DROP COLUMN junk;
 INSERT INTO t1 VALUES (1, 'aaa'), (2, 'bbb'), (3, 'ccc');
 CREATE TABLE t2 (x int, y text);
 SECURITY LABEL ON TABLE t2 IS 'system_u:object_r:sepgsql_ro_table_t:s0';
@@ -13,8 +14,9 @@ INSERT INTO t2 VALUES (1, 'xxx'), (2, 'yyy'), (3, 'zzz');
 CREATE TABLE t3 (s int, t text);
 SECURITY LABEL ON TABLE t3 IS 'system_u:object_r:sepgsql_fixed_table_t:s0';
 INSERT INTO t3 VALUES (1, 'sss'), (2, 'ttt'), (3, 'uuu');
-CREATE TABLE t4 (m int, n text);
+CREATE TABLE t4 (m int, junk int, n text);
 SECURITY LABEL ON TABLE t4 IS 'system_u:object_r:sepgsql_secret_table_t:s0';
+ALTER TABLE t4 DROP COLUMN junk;
 INSERT INTO t4 VALUES (1, 'mmm'), (2, 'nnn'), (3, 'ooo');
 CREATE TABLE t5 (e text, f text, g text);
 SECURITY LABEL ON TABLE t5 IS 'system_u:object_r:sepgsql_table_t:s0';
@@ -136,6 +138,16 @@ SELECT e,f FROM t5;			-- ok
 ---+---
 (0 rows)
 
+SELECT (t1.*)::record FROM t1;		-- ok
+   t1    
+---------
+ (1,aaa)
+ (2,bbb)
+ (3,ccc)
+(3 rows)
+
+SELECT (t4.*)::record FROM t4;		-- failed
+ERROR:  SELinux: security policy violation
 ---
 -- partitioned table parent
 SELECT * FROM t1p;			-- failed