0.8.12.7: Merge package locks, AKA "what can go wrong with a 3783 line patch?"

[sbcl.git] / src / pcl / defcombin.lisp

diff --git a/src/pcl/defcombin.lisp b/src/pcl/defcombin.lisp
index 8b71ed4..060f4a0 100644 (file)
--- a/src/pcl/defcombin.lisp
+++ b/src/pcl/defcombin.lisp
@@ -25,10 +25,13 @@
 \f
 (defmacro define-method-combination (&whole form &rest args)
   (declare (ignore args))
-  (if (and (cddr form)
-          (listp (caddr form)))
-      (expand-long-defcombin form)
-      (expand-short-defcombin form)))
+  `(progn
+     (with-single-package-locked-error
+        (:symbol ',(second form) "defining ~A as a method combination"))
+     ,(if (and (cddr form)
+              (listp (caddr form)))
+         (expand-long-defcombin form)
+         (expand-short-defcombin form))))
 \f
 ;;;; standard method combination