1 files changed, 42 insertions, 0 deletions
diff --git a/src/test/regress/expected/window.out b/src/test/regress/expected/window.out
index edc93d5729b..d5fd4045f9f 100644
--- a/src/test/regress/expected/window.out
+++ b/src/test/regress/expected/window.out
@@ -3821,3 +3821,45 @@ SELECT i, b, bool_and(b) OVER w, bool_or(b) OVER w
  5 | t | t        | t
 (5 rows)
 
+-- Tests for problems with failure to walk or mutate expressions
+-- within window frame clauses.
+-- test walker (fails with collation error if expressions are not walked)
+SELECT array_agg(i) OVER w
+  FROM generate_series(1,5) i
+WINDOW w AS (ORDER BY i ROWS BETWEEN (('foo' < 'foobar')::integer) PRECEDING AND CURRENT ROW);
+ array_agg 
+-----------
+ {1}
+ {1,2}
+ {2,3}
+ {3,4}
+ {4,5}
+(5 rows)
+
+-- test mutator (fails when inlined if expressions are not mutated)
+CREATE FUNCTION pg_temp.f(group_size BIGINT) RETURNS SETOF integer[]
+AS $$
+    SELECT array_agg(s) OVER w
+      FROM generate_series(1,5) s
+    WINDOW w AS (ORDER BY s ROWS BETWEEN CURRENT ROW AND GROUP_SIZE FOLLOWING)
+$$ LANGUAGE SQL STABLE;
+EXPLAIN (costs off) SELECT * FROM pg_temp.f(2);
+                      QUERY PLAN                      
+------------------------------------------------------
+ Subquery Scan on f
+   ->  WindowAgg
+         ->  Sort
+               Sort Key: s.s
+               ->  Function Scan on generate_series s
+(5 rows)
+
+SELECT * FROM pg_temp.f(2);
+    f    
+---------
+ {1,2,3}
+ {2,3,4}
+ {3,4,5}
+ {4,5}
+ {5}
+(5 rows)
+