From: Jeroen van Vianen <jeroenv@design.nl>

This patch solves the problem with multiple order by columns, with the
first one having NULL values.

src/backend/utils/sort/psort.c

@@ -7,7 +7,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/utils/sort/Attic/psort.c,v 1.33 1998/01/25 05:14:49 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/utils/sort/Attic/psort.c,v 1.34 1998/01/25 05:18:34 scrappy Exp $
  *
  * NOTES
  *		Sorts the first relation into the second relation.
@@ -1094,7 +1094,7 @@ _psort_cmp (HeapTuple *ltup, HeapTuple *rtup)
     int		result = 0;
     bool	isnull1, isnull2;
     
-    while ( nkey < PsortNkeys && !result )
+    for (nkey = 0; nkey < PsortNkeys && !result; nkey++ )
     {
 		lattr = heap_getattr(*ltup, InvalidBuffer,
 				     PsortKeys[nkey].sk_attno, 
@@ -1106,14 +1106,13 @@ _psort_cmp (HeapTuple *ltup, HeapTuple *rtup)
 				     &isnull2);
 		if ( isnull1 )
 		{
-	    	if ( isnull2 )
-	    		return (0);
-		    return(1);
+			if ( !isnull2 )
+				result = 1;
 		}
 		else if ( isnull2 )
-		    return (-1);
+		    result = -1;
 		
-		if (PsortKeys[nkey].sk_flags & SK_COMMUTE)
+		else if (PsortKeys[nkey].sk_flags & SK_COMMUTE)
 		{
 	    	if (!(result = -(long) (*fmgr_faddr(&PsortKeys[nkey].sk_func)) (rattr, lattr)))
 			result = (long) (*fmgr_faddr(&PsortKeys[nkey].sk_func)) (lattr, rattr);