From 116d2bba7eeaf25c544bc187e3ad2a8677a9a22c Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Tue, 19 Jun 2001 22:39:12 +0000
Subject: Add IS UNKNOWN, IS NOT UNKNOWN boolean tests, fix the existing
 boolean tests to return the correct results per SQL9x when given NULL inputs.
 Reimplement these tests as well as IS [NOT] NULL to have their own expression
 node types, instead of depending on special functions. From Joe Conway, with
 a little help from Tom Lane.

---
 src/backend/nodes/copyfuncs.c | 44 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 43 insertions(+), 1 deletion(-)

(limited to 'src/backend/nodes/copyfuncs.c')

diff --git a/src/backend/nodes/copyfuncs.c b/src/backend/nodes/copyfuncs.c
index 77ae4fb781a..6cf5b35d266 100644
--- a/src/backend/nodes/copyfuncs.c
+++ b/src/backend/nodes/copyfuncs.c
@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.144 2001/06/09 23:21:54 petere Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.145 2001/06/19 22:39:11 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1017,6 +1017,42 @@ _copyCaseWhen(CaseWhen *from)
 	return newnode;
 }
 
+/* ----------------
+ *		_copyNullTest
+ * ----------------
+ */
+static NullTest *
+_copyNullTest(NullTest *from)
+{
+	NullTest *newnode = makeNode(NullTest);
+
+	/*
+	 * copy remainder of node
+	 */
+	Node_Copy(from, newnode, arg);
+	newnode->nulltesttype = from->nulltesttype;
+
+	return newnode;
+}
+
+/* ----------------
+ *		_copyBooleanTest
+ * ----------------
+ */
+static BooleanTest *
+_copyBooleanTest(BooleanTest *from)
+{
+	BooleanTest *newnode = makeNode(BooleanTest);
+
+	/*
+	 * copy remainder of node
+	 */
+	Node_Copy(from, newnode, arg);
+	newnode->booltesttype = from->booltesttype;
+
+	return newnode;
+}
+
 static ArrayRef *
 _copyArrayRef(ArrayRef *from)
 {
@@ -2954,6 +2990,12 @@ copyObject(void *from)
 		case T_CaseWhen:
 			retval = _copyCaseWhen(from);
 			break;
+		case T_NullTest:
+			retval = _copyNullTest(from);
+			break;
+		case T_BooleanTest:
+			retval = _copyBooleanTest(from);
+			break;
 		case T_FkConstraint:
 			retval = _copyFkConstraint(from);
 			break;
-- 
cgit v1.2.3