* emacs-lisp/cl-lib.el (cl-endp): Conform to CL's semantics.

2 files changed, 11 insertions, 1 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index abe240a5ea4..733d060f453 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2014-05-19  Leo Liu  <sdl.web@gmail.com>
+
+        * emacs-lisp/cl-lib.el (cl-endp): Conform to CL's semantics.
+
 2014-05-18  Glenn Morris  <rgm@gnu.org>
 
         * loadup.el:
diff --git a/lisp/emacs-lisp/cl-lib.el b/lisp/emacs-lisp/cl-lib.el
index 929e3dfb2f5..9ca9459987f 100644
--- a/lisp/emacs-lisp/cl-lib.el
+++ b/lisp/emacs-lisp/cl-lib.el
@@ -358,7 +358,13 @@ SEQ, this is like `mapcar'.  With several, it is like the Common Lisp
 (cl--defalias 'cl-first 'car)
 (cl--defalias 'cl-second 'cadr)
 (cl--defalias 'cl-rest 'cdr)
-(cl--defalias 'cl-endp 'null)
+
+(defun cl-endp (x)
+  "Return true if X is the empty list; false if it is a cons.
+Signal an error if X is not a list."
+  (if (listp x)
+      (null x)
+    (signal 'wrong-type-argument (list 'list x 'x))))
 
 (cl--defalias 'cl-third 'cl-caddr "Return the third element of the list X.")
 (cl--defalias 'cl-fourth 'cl-cadddr "Return the fourth element of the list X.")