Provide `char-code-limit', implement the GNU equivalent in terms of it. src/ChangeLog addition: 2015-03-15 Aidan Kehoe <kehoea@parhasard.net> * text.h: Make CHAR_CODE_LIMIT available as a #define. * text.h (valid_ichar_p): Use it. * text.c: Make a fixnum Vchar_code_limit available here. * text.c (non_ascii_valid_ichar_p): Use CHAR_CODE_LIMIT. * text.c (vars_of_text): Make `char-code-limit' available to Lisp. tests/ChangeLog addition: 2015-03-15 Aidan Kehoe <kehoea@parhasard.net> * automated/mule-tests.el (test-chars): Use char-code-limit explicitly here, instead of hardcoding the corresponding values. lisp/ChangeLog addition: 2015-03-16 Aidan Kehoe <kehoea@parhasard.net> * obsolete.el (max-char): Make this available for compatiblity with GNU, implement it in terms of char-code-limit.

--- a/lisp/obsolete.el	Sun Mar 15 21:13:23 2015 +0000
+++ b/lisp/obsolete.el	Mon Mar 16 00:09:46 2015 +0000
@@ -485,5 +485,15 @@
 (make-obsolete 'remrassoc "use delete* with :test #'equal, :key #'cdr")
 (make-obsolete 'remrassq "use delete* with :test #'eq, :key #'cdr")
 
+(defun max-char ()
+  "Return a fixnum one less than `char-code-limit'.
+
+In contrast with GNU Emacs, this is not necessarily a valid character, but it
+is an inclusive upper bound on the possible values returned by `char-int'."
+  (1- char-code-limit))
+(make-compatible
+ 'max-char
+ "consider `char-code-limit', which gives an exclusive upper bound")
+
 (provide 'obsolete)
 ;;; obsolete.el ends here