DEFTAIL: bugfix when function directly recurses. The return-from in the

generated FLET then references the FLET rather than the surrounding function.
Fixed by introducing anon block as the target of the return instead.

1 files changed, 12 insertions, 10 deletions

diff --git a/tail-recursion.lisp b/tail-recursion.lisp
index 635982e..8381345 100644
--- a/tail-recursion.lisp
+++ b/tail-recursion.lisp
@@ -252,6 +252,7 @@
 (defmacro deftail (name lambda-list &body body)
   (let ((escape (gensym "ESCAPE-"))
         (other-tails `(,name))
+	(anon-block (gensym))
 	(docstring)
         (decls))
     (when (stringp (first body))
@@ -267,13 +268,14 @@
     `(defun ,name (,@lambda-list &aux (,escape *tail-escape*))
        ,@docstring
        ,@decls
-       (flet (,@(loop for other in other-tails
-                      collecting `(,other (&rest args)
-                                    (return-from ,name
-                                       (let ((*tail-escape* ,escape))
-                                         (tail-call #',other args)))))
-               (tail-call (fun args)
-                 (let ((*tail-escape* ,escape))
-                   (tail-call fun args))))
-         (let ((*tail-escape* nil))
-           ,@body)))))
+       (block ,anon-block
+	 (flet (,@(loop for other in other-tails
+			collecting `(,other (&rest args)
+				      (return-from ,anon-block
+					 (let ((*tail-escape* ,escape))
+					   (tail-call #',other args)))))
+		 (tail-call (fun args)
+		   (let ((*tail-escape* ,escape))
+		     (tail-call fun args))))
+	   (let ((*tail-escape* nil))
+	     ,@body))))))