Fix things so that you can still do "select foo()" where foo is a SQL

function returning setof record.  This used to work, more or less
accidentally, but I had broken it while extending the code to allow
materialize-mode functions to be called in select lists.  Add a regression
test case so it doesn't get broken again.  Per gripe from Greg Davidson.

src/test/regress/expected/rangefuncs.out

@@ -763,3 +763,70 @@ select t.a, t, t.a from foo1(10000) t limit 1;
 (1 row)
 
 drop function foo1(n integer);
+-- test use of SQL functions returning record
+-- this is supported in some cases where the query doesn't specify
+-- the actual record type ...
+create function array_to_set(anyarray) returns setof record as $$
+  select i AS "index", $1[i] AS "value" from generate_subscripts($1, 1) i
+$$ language sql strict immutable;
+select array_to_set(array['one', 'two']);
+ array_to_set 
+--------------
+ (1,one)
+ (2,two)
+(2 rows)
+
+select * from array_to_set(array['one', 'two']) as t(f1 int,f2 text);
+ f1 | f2  
+----+-----
+  1 | one
+  2 | two
+(2 rows)
+
+select * from array_to_set(array['one', 'two']); -- fail
+ERROR:  a column definition list is required for functions returning "record"
+LINE 1: select * from array_to_set(array['one', 'two']);
+                      ^
+create temp table foo(f1 int8, f2 int8);
+create function testfoo() returns record as $$
+  insert into foo values (1,2) returning *;
+$$ language sql;
+select testfoo();
+ testfoo 
+---------
+ (1,2)
+(1 row)
+
+select * from testfoo() as t(f1 int8,f2 int8);
+ f1 | f2 
+----+----
+  1 |  2
+(1 row)
+
+select * from testfoo(); -- fail
+ERROR:  a column definition list is required for functions returning "record"
+LINE 1: select * from testfoo();
+                      ^
+drop function testfoo();
+create function testfoo() returns setof record as $$
+  insert into foo values (1,2), (3,4) returning *;
+$$ language sql;
+select testfoo();
+ testfoo 
+---------
+ (1,2)
+ (3,4)
+(2 rows)
+
+select * from testfoo() as t(f1 int8,f2 int8);
+ f1 | f2 
+----+----
+  1 |  2
+  3 |  4
+(2 rows)
+
+select * from testfoo(); -- fail
+ERROR:  a column definition list is required for functions returning "record"
+LINE 1: select * from testfoo();
+                      ^
+drop function testfoo();

src/test/regress/sql/rangefuncs.sql

@@ -351,3 +351,37 @@ reset work_mem;
 select t.a, t, t.a from foo1(10000) t limit 1;
 
 drop function foo1(n integer);
+
+-- test use of SQL functions returning record
+-- this is supported in some cases where the query doesn't specify
+-- the actual record type ...
+
+create function array_to_set(anyarray) returns setof record as $$
+  select i AS "index", $1[i] AS "value" from generate_subscripts($1, 1) i
+$$ language sql strict immutable;
+
+select array_to_set(array['one', 'two']);
+select * from array_to_set(array['one', 'two']) as t(f1 int,f2 text);
+select * from array_to_set(array['one', 'two']); -- fail
+
+create temp table foo(f1 int8, f2 int8);
+
+create function testfoo() returns record as $$
+  insert into foo values (1,2) returning *;
+$$ language sql;
+
+select testfoo();
+select * from testfoo() as t(f1 int8,f2 int8);
+select * from testfoo(); -- fail
+
+drop function testfoo();
+
+create function testfoo() returns setof record as $$
+  insert into foo values (1,2), (3,4) returning *;
+$$ language sql;
+
+select testfoo();
+select * from testfoo() as t(f1 int8,f2 int8);
+select * from testfoo(); -- fail
+
+drop function testfoo();