Fix a VDBE stack overflow that occurs when the left-hand side of an IN
expression is NULL and the result is stored on the stack rather than used
to control a jump.  Ticket #668. (CVS 1299)

FossilOrigin-Name: fc7a7975b03c144c2db3566facd008d3701c735e
diff --git a/src/expr.c b/src/expr.c
index dca48e3..eafc50c 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -12,7 +12,7 @@
 ** This file contains routines used for analyzing expressions and
 ** for generating VDBE code that evaluates expressions in SQLite.
 **
-** $Id: expr.c,v 1.112 2004/02/25 13:47:31 drh Exp $
+** $Id: expr.c,v 1.113 2004/03/17 23:32:08 drh Exp $
 */
 #include "sqliteInt.h"
 #include <ctype.h>
@@ -1163,7 +1163,7 @@
       sqliteExprCode(pParse, pExpr->pLeft);
       addr = sqliteVdbeCurrentAddr(v);
       sqliteVdbeAddOp(v, OP_NotNull, -1, addr+4);
-      sqliteVdbeAddOp(v, OP_Pop, 1, 0);
+      sqliteVdbeAddOp(v, OP_Pop, 2, 0);
       sqliteVdbeAddOp(v, OP_String, 0, 0);
       sqliteVdbeAddOp(v, OP_Goto, 0, addr+6);
       if( pExpr->pSelect ){