diff options
Diffstat (limited to 'lisp/emacs-lisp/cl.el')
| -rw-r--r-- | lisp/emacs-lisp/cl.el | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/lisp/emacs-lisp/cl.el b/lisp/emacs-lisp/cl.el index 222407f86f2..d2d68189230 100644 --- a/lisp/emacs-lisp/cl.el +++ b/lisp/emacs-lisp/cl.el @@ -155,7 +155,11 @@ Like (push X PLACE), except that the list is unmodified if X is `eql' to an element already on the list. \nKeywords supported: :test :test-not :key \n(fn X PLACE [KEYWORD VALUE]...)" - (if (symbolp place) (list 'setq place (list* 'adjoin x place keys)) + (if (symbolp place) + (if (null keys) + `(let ((x ,x)) + (if (memql x ,place) ,place (setq ,place (cons x ,place)))) + (list 'setq place (list* 'adjoin x place keys))) (list* 'callf2 'adjoin x place keys))) (defun cl-set-elt (seq n val) |