compiler warning

llex.c

@@ -1,5 +1,5 @@
 /*
-** $Id: llex.c,v 2.17 2005/12/22 16:19:56 roberto Exp roberto $
+** $Id: llex.c,v 2.18 2006/01/23 20:06:19 roberto Exp roberto $
 ** Lexical Analyzer
 ** See Copyright Notice in lua.h
 */
@@ -166,7 +166,7 @@ static int check_next (LexState *ls, const char *set) {
 
 
 static void buffreplace (LexState *ls, char from, char to) {
-  int n = luaZ_bufflen(ls->buff);
+  size_t n = luaZ_bufflen(ls->buff);
   char *p = luaZ_buffer(ls->buff);
   while (n--)
     if (p[n] == from) p[n] = to;