diff -uNr readline-4.3.orig/chardefs.h readline-4.3/chardefs.h
--- readline-4.3.orig/chardefs.h	2002-02-14 18:38:18 +0200
+++ readline-4.3/chardefs.h	2005-10-20 11:45:25 +0300
@@ -24,6 +24,7 @@
 #define _CHARDEFS_H_
 
 #include <ctype.h>
+#include "rlmbutil.h"
 
 #if defined (HAVE_CONFIG_H)
 #  if defined (HAVE_STRING_H)
@@ -82,24 +83,24 @@
 /* Some systems define these; we want our definitions. */
 #undef ISPRINT
 
-#define ISALNUM(c)	(IN_CTYPE_DOMAIN (c) && isalnum (c))
-#define ISALPHA(c)	(IN_CTYPE_DOMAIN (c) && isalpha (c))
-#define ISDIGIT(c)	(IN_CTYPE_DOMAIN (c) && isdigit (c))
-#define ISLOWER(c)	(IN_CTYPE_DOMAIN (c) && islower (c))
-#define ISPRINT(c)	(IN_CTYPE_DOMAIN (c) && isprint (c))
-#define ISUPPER(c)	(IN_CTYPE_DOMAIN (c) && isupper (c))
-#define ISXDIGIT(c)	(IN_CTYPE_DOMAIN (c) && isxdigit (c))
+#define ISALNUM(c)     ((MB_CUR_MAX == 1 || IN_CTYPE_DOMAIN (c)) && isalnum ((unsigned char) c))
+#define ISALPHA(c)     ((MB_CUR_MAX == 1 || IN_CTYPE_DOMAIN (c)) && isalpha ((unsigned char) c))
+#define ISDIGIT(c)     ((MB_CUR_MAX == 1 || IN_CTYPE_DOMAIN (c)) && isdigit ((unsigned char) c))
+#define ISLOWER(c)     ((MB_CUR_MAX == 1 || IN_CTYPE_DOMAIN (c)) && islower ((unsigned char) c))
+#define ISPRINT(c)     ((MB_CUR_MAX == 1 || IN_CTYPE_DOMAIN (c)) && isprint ((unsigned char) c))
+#define ISUPPER(c)     ((MB_CUR_MAX == 1 || IN_CTYPE_DOMAIN (c)) && isupper ((unsigned char) c))
+#define ISXDIGIT(c)    ((MB_CUR_MAX == 1 || IN_CTYPE_DOMAIN (c)) && isxdigit ((unsigned char) c))
 
-#define _rl_lowercase_p(c)	(NON_NEGATIVE(c) && ISLOWER(c))
-#define _rl_uppercase_p(c)	(NON_NEGATIVE(c) && ISUPPER(c))
+#define _rl_lowercase_p(c)     (ISLOWER(c))
+#define _rl_uppercase_p(c)     (ISUPPER(c))
 #define _rl_digit_p(c)		((c) >= '0' && (c) <= '9')
 
-#define _rl_pure_alphabetic(c)	(NON_NEGATIVE(c) && ISALPHA(c))
-#define ALPHABETIC(c)		(NON_NEGATIVE(c) && ISALNUM(c))
+#define _rl_pure_alphabetic(c) (ISALPHA(c))
+#define ALPHABETIC(c)          (ISALNUM(c))
 
 #ifndef _rl_to_upper
-#  define _rl_to_upper(c) (_rl_lowercase_p(c) ? toupper((unsigned char)c) : (c))
-#  define _rl_to_lower(c) (_rl_uppercase_p(c) ? tolower((unsigned char)c) : (c))
+#  define _rl_to_upper(c) (_rl_lowercase_p(c) ? toupper((unsigned char)c) : ((unsigned char) c))
+#  define _rl_to_lower(c) (_rl_uppercase_p(c) ? tolower((unsigned char)c) : ((unsigned char) c))
 #endif
 
 #ifndef _rl_digit_value