2 files changed, 40 insertions, 0 deletions
diff --git a/src/test/regress/expected/groupingsets.out b/src/test/regress/expected/groupingsets.out
index 260ccd52c87..091aada0900 100644
--- a/src/test/regress/expected/groupingsets.out
+++ b/src/test/regress/expected/groupingsets.out
@@ -352,6 +352,35 @@ select a, d, grouping(a,b,c)
  2 | 2 |        2
 (4 rows)
 
+-- check that distinct grouping columns are kept separate
+-- even if they are equal()
+explain (costs off)
+select g as alias1, g as alias2
+  from generate_series(1,3) g
+ group by alias1, rollup(alias2);
+                   QUERY PLAN                   
+------------------------------------------------
+ GroupAggregate
+   Group Key: g, g
+   Group Key: g
+   ->  Sort
+         Sort Key: g
+         ->  Function Scan on generate_series g
+(6 rows)
+
+select g as alias1, g as alias2
+  from generate_series(1,3) g
+ group by alias1, rollup(alias2);
+ alias1 | alias2 
+--------+--------
+      1 |      1
+      1 |       
+      2 |      2
+      2 |       
+      3 |      3
+      3 |       
+(6 rows)
+
 -- simple rescan tests
 select a, b, sum(v.x)
   from (values (1),(2)) v(x), gstest_data(v.x)
diff --git a/src/test/regress/sql/groupingsets.sql b/src/test/regress/sql/groupingsets.sql
index 71cc0ec9007..a9938d57b7d 100644
--- a/src/test/regress/sql/groupingsets.sql
+++ b/src/test/regress/sql/groupingsets.sql
@@ -130,6 +130,17 @@ select a, d, grouping(a,b,c)
   from gstest3
  group by grouping sets ((a,b), (a,c));
 
+-- check that distinct grouping columns are kept separate
+-- even if they are equal()
+explain (costs off)
+select g as alias1, g as alias2
+  from generate_series(1,3) g
+ group by alias1, rollup(alias2);
+
+select g as alias1, g as alias2
+  from generate_series(1,3) g
+ group by alias1, rollup(alias2);
+
 -- simple rescan tests
 
 select a, b, sum(v.x)