Make sure the column name resolver does not try to duplicate Expr.u.zToken
when the Expr.u.iValue union member is the element being used. (CVS 6684)

FossilOrigin-Name: 376ecf0d87e4a2329f5861401f83ed9ceb35d528
diff --git a/src/resolve.c b/src/resolve.c
index 015fe4b..b536dcf 100644
--- a/src/resolve.c
+++ b/src/resolve.c
@@ -14,7 +14,7 @@
 ** resolve all identifiers by associating them with a particular
 ** table and column.
 **
-** $Id: resolve.c,v 1.24 2009/05/28 01:00:55 drh Exp $
+** $Id: resolve.c,v 1.25 2009/05/28 12:49:53 drh Exp $
 */
 #include "sqliteInt.h"
 #include <stdlib.h>
@@ -71,6 +71,8 @@
       pEList->a[iCol].iAlias = (u16)(++pParse->nAlias);
     }
     pDup->iTable = pEList->a[iCol].iAlias;
+  }else if( ExprHasProperty(pOrig, EP_IntValue) || pOrig->u.zToken==0 ){
+    pDup = sqlite3ExprDup(db, pOrig, 0);
   }else{
     char *zToken = pOrig->u.zToken;
     pOrig->u.zToken = 0;