Fix IS NULL and IS NOT NULL tests on row-valued expressions to conform to

the SQL spec, viz IS NULL is true if all the row's fields are null, IS NOT
NULL is true if all the row's fields are not null.  The former coding got
this right for a limited number of cases with IS NULL (ie, those where it
could disassemble a ROW constructor at parse time), but was entirely wrong
for IS NOT NULL.  Per report from Teodor.

I desisted from changing the behavior for arrays, since on closer inspection
it's not clear that there's any support for that in the SQL spec.  This
probably needs more consideration.

1 files changed, 13 insertions, 1 deletions

diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 769206e02c8..53e3a5bf552 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/cache/lsyscache.c,v 1.136 2006/08/15 22:36:17 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/lsyscache.c,v 1.137 2006/09/28 20:51:42 tgl Exp $
  *
  * NOTES
  *	  Eventually, the index information should go through here, too.
@@ -1717,6 +1717,18 @@ get_typtype(Oid typid)
 }
 
 /*
+ * type_is_rowtype
+ *
+ *		Convenience function to determine whether a type OID represents
+ *		a "rowtype" type --- either RECORD or a named composite type.
+ */
+bool
+type_is_rowtype(Oid typid)
+{
+	return (typid == RECORDOID || get_typtype(typid) == 'c');
+}
+
+/*
  * get_typ_typrelid
  *
  *		Given the type OID, get the typrelid (InvalidOid if not a complex