1 files changed, 78 insertions, 0 deletions
diff --git a/src/test/regress/expected/transactions.out b/src/test/regress/expected/transactions.out
index 955558d690b..1c8ba64c5c0 100644
--- a/src/test/regress/expected/transactions.out
+++ b/src/test/regress/expected/transactions.out
@@ -374,6 +374,84 @@ ERROR:  portal "c" cannot be run
 	FETCH 10 FROM c;
 ERROR:  portal "c" cannot be run
 COMMIT;
+--
+-- Check that "stable" functions are really stable.  They should not be
+-- able to see the partial results of the calling query.  (Ideally we would
+-- also check that they don't see commits of concurrent transactions, but
+-- that's a mite hard to do within the limitations of pg_regress.)
+--
+select * from xacttest;
+  a  |    b    
+-----+---------
+  56 |     7.8
+ 100 |  99.097
+   0 | 0.09561
+  42 |  324.78
+ 777 | 777.777
+(5 rows)
+
+create or replace function max_xacttest() returns smallint language sql as
+'select max(a) from xacttest' stable;
+begin;
+update xacttest set a = max_xacttest() + 10 where a > 0;
+select * from xacttest;
+  a  |    b    
+-----+---------
+   0 | 0.09561
+ 787 |     7.8
+ 787 |  99.097
+ 787 |  324.78
+ 787 | 777.777
+(5 rows)
+
+rollback;
+-- But a volatile function can see the partial results of the calling query
+create or replace function max_xacttest() returns smallint language sql as
+'select max(a) from xacttest' volatile;
+begin;
+update xacttest set a = max_xacttest() + 10 where a > 0;
+select * from xacttest;
+  a  |    b    
+-----+---------
+   0 | 0.09561
+ 787 |     7.8
+ 797 |  99.097
+ 807 |  324.78
+ 817 | 777.777
+(5 rows)
+
+rollback;
+-- Now the same test with plpgsql (since it depends on SPI which is different)
+create or replace function max_xacttest() returns smallint language plpgsql as
+'begin return max(a) from xacttest; end' stable;
+begin;
+update xacttest set a = max_xacttest() + 10 where a > 0;
+select * from xacttest;
+  a  |    b    
+-----+---------
+   0 | 0.09561
+ 787 |     7.8
+ 787 |  99.097
+ 787 |  324.78
+ 787 | 777.777
+(5 rows)
+
+rollback;
+create or replace function max_xacttest() returns smallint language plpgsql as
+'begin return max(a) from xacttest; end' volatile;
+begin;
+update xacttest set a = max_xacttest() + 10 where a > 0;
+select * from xacttest;
+  a  |    b    
+-----+---------
+   0 | 0.09561
+ 787 |     7.8
+ 797 |  99.097
+ 807 |  324.78
+ 817 | 777.777
+(5 rows)
+
+rollback;
 -- test case for problems with dropping an open relation during abort
 BEGIN;
 	savepoint x;