Add a regression test case to catch breakage of GROUP BY

and aggregate functions in queries that use inheritance.

src/test/regress/input/misc.source

@@ -100,6 +100,13 @@ SELECT class, c FROM e_star* x WHERE x.c NOTNULL;
 
 SELECT * FROM f_star* x WHERE x.c ISNULL;
 
+-- grouping and aggregation on inherited sets have been busted in the past...
+
+SELECT sum(a) FROM a_star*;
+
+SELECT class, sum(a) FROM a_star* GROUP BY class;
+
+
 ALTER TABLE f_star RENAME COLUMN f TO ff;
 
 ALTER TABLE e_star* RENAME COLUMN e TO ee;

src/test/regress/output/misc.source

@@ -178,6 +178,23 @@ f    |  | |   |((11111111,33333333),(22222222,44444444))
 f    |  | |   |                                         
 (8 rows)
 
+QUERY: SELECT sum(a) FROM a_star*;
+sum
+---
+355
+(1 row)
+
+QUERY: SELECT class, sum(a) FROM a_star* GROUP BY class;
+class|sum
+-----+---
+a    |  3
+b    |  7
+c    | 11
+d    | 84
+e    | 66
+f    |184
+(6 rows)
+
 QUERY: ALTER TABLE f_star RENAME COLUMN f TO ff;
 QUERY: ALTER TABLE e_star* RENAME COLUMN e TO ee;
 QUERY: ALTER TABLE d_star* RENAME COLUMN d TO dd;