Handle varalias chains, custom variables in #'user-variable-p. src/ChangeLog addition: 2008-08-23 Aidan Kehoe <kehoea@parhasard.net> * eval.c (Fuser_variable_p): Moved to symbols.c * symbols.c (Fcustom_variable_p): Moved here from custom.el. (user_variable_alias_check_fun): Mapper function used in `user-variable-p'. (Fuser_variable_p): Moved here from eval.c, to allow it to examine the variable alias chain. Expanded to check each entry in the variable alias chain for signs of being a user variable; documentation updated, noting the differences between GNU's behaviour and ours (ours is a little more sensible) (map_varalias_chain): New. Given a C function, call it at least once for each symbol in a symbol's varalias chain, signalling an error if there's a cycle, and returning immediately if the function returns something other than Qzero. (Fdefvaralias): Correct the use of the word "alias" in the docstring and in the argument name. Motivate this in a comment. Add support for a DOCSTRING argument, something GNU has too, and document this * gc.c (vars_of_gc): Start the docstring of `garbage-collection-messages' with an asterisk, to indicate that it's a user variable. lisp/ChangeLog addition: 2008-08-23 Aidan Kehoe <kehoea@parhasard.net> * custom.el: Move #'custom-variable-p to C, since it's now called from #'user-variable-p.

--- a/src/eval.c	Wed Aug 20 17:39:56 2008 +0200
+++ b/src/eval.c	Sat Aug 23 16:38:51 2008 +0200
@@ -1356,29 +1356,8 @@
   return sym;
 }
 
-DEFUN ("user-variable-p", Fuser_variable_p, 1, 1, 0, /*
-Return t if VARIABLE is intended to be set and modified by users.
-\(The alternative is a variable used internally in a Lisp program.)
-Determined by whether the first character of the documentation
-for the variable is `*'.
-*/
-       (variable))
-{
-  Lisp_Object documentation = Fget (variable, Qvariable_documentation, Qnil);
-
-  return
-    ((INTP (documentation) && XINT (documentation) < 0) ||
-
-     (STRINGP (documentation) &&
-      (string_byte (documentation, 0) == '*')) ||
-
-     /* If (STRING . INTEGER), a negative integer means a user variable. */
-     (CONSP (documentation)
-      && STRINGP (XCAR (documentation))
-      && INTP (XCDR (documentation))
-      && XINT (XCDR (documentation)) < 0)) ?
-    Qt : Qnil;
-}
+/* XEmacs: user-variable-p is in symbols.c, since it needs to mess around
+   with the symbol variable aliases. */
 
 DEFUN ("macroexpand-internal", Fmacroexpand_internal, 1, 2, 0, /*
 Return result of expanding macros at top level of FORM.
@@ -6582,7 +6561,6 @@
   DEFSUBR (Fdefmacro);
   DEFSUBR (Fdefvar);
   DEFSUBR (Fdefconst);
-  DEFSUBR (Fuser_variable_p);
   DEFSUBR (Flet);
   DEFSUBR (FletX);
   DEFSUBR (Fwhile);