Mon Jan 25 07:03:27 UTC 2010  pix@kepibu.org
  * (cond (a b) (c d) nil) isn't really valid
diff -rN -u old-cl-unification/match-block.lisp new-cl-unification/match-block.lisp
--- old-cl-unification/match-block.lisp	2016-01-25 08:34:14.000000000 +0000
+++ new-cl-unification/match-block.lisp	2016-01-25 08:34:14.000000000 +0000
@@ -205,7 +205,7 @@
                  (,errorp
                   (error 'unification-non-exhaustive
                          :format-control "Non exhaustive matching."))
-                 ,(when default-clause (cons t (cdr default-clause)))))))
+                 ,@(when default-clause `((t ,@(cdr default-clause))))))))
     ))