2 files changed, 35 insertions, 0 deletions
diff --git a/src/test/regress/expected/join.out b/src/test/regress/expected/join.out
index 5e17432198e..6503dd1d2f8 100644
--- a/src/test/regress/expected/join.out
+++ b/src/test/regress/expected/join.out
@@ -3109,6 +3109,32 @@ explain (costs off)
          ->  Function Scan on generate_series g
 (4 rows)
 
+-- lateral with UNION ALL subselect
+explain (costs off)
+  select * from generate_series(100,200) g,
+    lateral (select * from int8_tbl a where g = q1 union all
+             select * from int8_tbl b where g = q2) ss;
+                QUERY PLAN                
+------------------------------------------
+ Nested Loop
+   ->  Function Scan on generate_series g
+   ->  Append
+         ->  Seq Scan on int8_tbl a
+               Filter: (g.g = q1)
+         ->  Seq Scan on int8_tbl b
+               Filter: (g.g = q2)
+(7 rows)
+
+select * from generate_series(100,200) g,
+  lateral (select * from int8_tbl a where g = q1 union all
+           select * from int8_tbl b where g = q2) ss;
+  g  |        q1        |        q2        
+-----+------------------+------------------
+ 123 |              123 |              456
+ 123 |              123 | 4567890123456789
+ 123 | 4567890123456789 |              123
+(3 rows)
+
 -- test some error cases where LATERAL should have been used but wasn't
 select f1,g from int4_tbl a, generate_series(0, f1) g;
 ERROR:  column "f1" does not exist
diff --git a/src/test/regress/sql/join.sql b/src/test/regress/sql/join.sql
index 5de98dc0a72..40db5602dd4 100644
--- a/src/test/regress/sql/join.sql
+++ b/src/test/regress/sql/join.sql
@@ -876,6 +876,15 @@ explain (costs off)
 explain (costs off)
   select count(*) from tenk1 a cross join lateral generate_series(1,two) g;
 
+-- lateral with UNION ALL subselect
+explain (costs off)
+  select * from generate_series(100,200) g,
+    lateral (select * from int8_tbl a where g = q1 union all
+             select * from int8_tbl b where g = q2) ss;
+select * from generate_series(100,200) g,
+  lateral (select * from int8_tbl a where g = q1 union all
+           select * from int8_tbl b where g = q2) ss;
+
 -- test some error cases where LATERAL should have been used but wasn't
 select f1,g from int4_tbl a, generate_series(0, f1) g;
 select f1,g from int4_tbl a, generate_series(0, a.f1) g;