Merge from trunk

1 files changed, 10 insertions, 48 deletions

diff --git a/lisp/subr.el b/lisp/subr.el
index d7df38626bd..1503fbab14b 100644
--- a/lisp/subr.el
+++ b/lisp/subr.el
@@ -1,7 +1,8 @@
 ;;; subr.el --- basic lisp subroutines for Emacs
 
 ;; Copyright (C) 1985, 1986, 1992, 1994, 1995, 1999, 2000, 2001, 2002, 2003,
-;;   2004, 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+;;   2004, 2005, 2006, 2007, 2008, 2009, 2010
+;;   Free Software Foundation, Inc.
 
 ;; Maintainer: FSF
 ;; Keywords: internal
@@ -288,14 +289,11 @@ If LIST is nil, return nil.
 If N is non-nil, return the Nth-to-last link of LIST.
 If N is bigger than the length of LIST, return LIST."
   (if n
-      (let ((m 0) (p list))
-	(while (consp p)
-	  (setq m (1+ m) p (cdr p)))
-	(if (<= n 0) p
-	  (if (< n m) (nthcdr (- m n) list) list)))
-    (while (consp (cdr list))
-      (setq list (cdr list)))
-    list))
+      (and (>= n 0)
+           (let ((m (safe-length list)))
+             (if (< n m) (nthcdr (- m n) list) list)))
+    (and list
+         (nthcdr (1- (safe-length list)) list))))
 
 (defun butlast (list &optional n)
   "Return a copy of LIST with the last N elements removed."
@@ -1023,7 +1021,6 @@ and `event-end' functions."
 (define-obsolete-function-alias 'eval-current-buffer 'eval-buffer "22.1")
 (define-obsolete-function-alias 'string-to-int 'string-to-number "22.1")
 
-(make-obsolete 'char-bytes "now always returns 1." "20.4")
 (make-obsolete 'forward-point "use (+ (point) N) instead." "23.1")
 
 (defun insert-string (&rest args)
@@ -1098,11 +1095,6 @@ is converted into a string by expressing it in decimal."
 (make-obsolete 'process-filter-multibyte-p nil "23.1")
 (make-obsolete 'set-process-filter-multibyte nil "23.1")
 
-(defconst directory-sep-char ?/
-  "Directory separator character for built-in functions that return file names.
-The value is always ?/.")
-(make-obsolete-variable 'directory-sep-char "do not use it, just use `/'." "21.1")
-
 (make-obsolete-variable
  'mode-line-inverse-video
  "use the appropriate faces instead."
@@ -1169,37 +1161,6 @@ to reread, so it now uses nil to mean `no event', instead of -1."
 
 ;;;; Hook manipulation functions.
 
-(defun make-local-hook (hook)
-  "Make the hook HOOK local to the current buffer.
-The return value is HOOK.
-
-You never need to call this function now that `add-hook' does it for you
-if its LOCAL argument is non-nil.
-
-When a hook is local, its local and global values
-work in concert: running the hook actually runs all the hook
-functions listed in *either* the local value *or* the global value
-of the hook variable.
-
-This function works by making t a member of the buffer-local value,
-which acts as a flag to run the hook functions in the default value as
-well.  This works for all normal hooks, but does not work for most
-non-normal hooks yet.  We will be changing the callers of non-normal
-hooks so that they can handle localness; this has to be done one by
-one.
-
-This function does nothing if HOOK is already local in the current
-buffer.
-
-Do not use `make-local-variable' to make a hook variable buffer-local."
-  (if (local-variable-p hook)
-      nil
-    (or (boundp hook) (set hook nil))
-    (make-local-variable hook)
-    (set hook (list t)))
-  hook)
-(make-obsolete 'make-local-hook "not necessary any more." "21.1")
-
 (defun add-hook (hook function &optional append local)
   "Add to the value of HOOK the function FUNCTION.
 FUNCTION is not added if already present.
@@ -2426,8 +2387,9 @@ Otherwise, return nil."
   (or (stringp object) (null object)))
 
 (defun booleanp (object)
-  "Return non-nil if OBJECT is one of the two canonical boolean values: t or nil."
-  (memq object '(nil t)))
+  "Return t if OBJECT is one of the two canonical boolean values: t or nil.
+Otherwise, return nil."
+  (and (memq object '(nil t)) t))
 
 (defun field-at-pos (pos)
   "Return the field at position POS, taking stickiness etc into account."