2 files changed, 14 insertions, 6 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b5a4857f9f8..2554bd6d83a 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,10 @@
+2013-08-29  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * emacs-lisp/cl-macs.el (cl-defsubst): Make it clear that args
+        are immutable.  Don't use `unsafe' any more.
+        (cl--defsubst-expand): Don't substitute at the same time as keeping
+        a residual unused let-binding.  Don't use `unsafe' any more.
+
 2013-08-29  Glenn Morris  <rgm@gnu.org>
 
         * calendar/cal-china.el (calendar-chinese-year-cache):
diff --git a/lisp/emacs-lisp/cl-macs.el b/lisp/emacs-lisp/cl-macs.el
index d9d6658811f..af7c41d5c4c 100644
--- a/lisp/emacs-lisp/cl-macs.el
+++ b/lisp/emacs-lisp/cl-macs.el
@@ -2693,15 +2693,16 @@ macro that returns its `&whole' argument."
 ;;;###autoload
 (defmacro cl-defsubst (name args &rest body)
   "Define NAME as a function.
-Like `defun', except the function is automatically declared `inline',
+Like `defun', except the function is automatically declared `inline' and
+the arguments are immutable.
 ARGLIST allows full Common Lisp conventions, and BODY is implicitly
 surrounded by (cl-block NAME ...).
+The function's arguments should be treated as immutable.
 
 \(fn NAME ARGLIST [DOCSTRING] BODY...)"
   (declare (debug cl-defun) (indent 2))
   (let* ((argns (cl--arglist-args args)) (p argns)
-         (pbody (cons 'progn body))
-         (unsafe (not (cl--safe-expr-p pbody))))
+         (pbody (cons 'progn body)))
     (while (and p (eq (cl--expr-contains args (car p)) 1)) (pop p))
     `(progn
        ,(if p nil   ; give up if defaults refer to earlier args
@@ -2717,10 +2718,10 @@ surrounded by (cl-block NAME ...).
               ;; does not pay attention to the argvs (and
               ;; cl-expr-access-order itself is also too naive).
               nil
-              ,(and (memq '&key args) 'cl-whole) ,unsafe ,@argns)))
+              ,(and (memq '&key args) 'cl-whole) nil ,@argns)))
        (cl-defun ,name ,args ,@body))))
 
-(defun cl--defsubst-expand (argns body simple whole unsafe &rest argvs)
+(defun cl--defsubst-expand (argns body simple whole _unsafe &rest argvs)
   (if (and whole (not (cl--safe-expr-p (cons 'progn argvs)))) whole
     (if (cl--simple-exprs-p argvs) (setq simple t))
     (let* ((substs ())
@@ -2728,7 +2729,7 @@ surrounded by (cl-block NAME ...).
                        (cl-mapcar (lambda (argn argv)
                                     (if (or simple (macroexp-const-p argv))
                                         (progn (push (cons argn argv) substs)
-                                               (and unsafe (list argn argv)))
+                                               nil)
                                       (list argn argv)))
                                   argns argvs))))
       ;; FIXME: `sublis/subst' will happily substitute the symbol