2000-11-08 08:38:30 ShengHuo ZHU <zsh@cs.rochester.edu>

[gnus] / lisp / gnus-util.el

diff --git a/lisp/gnus-util.el b/lisp/gnus-util.el
index df776a7..47c1302 100644 (file)
--- a/lisp/gnus-util.el
+++ b/lisp/gnus-util.el
@@ -974,6 +974,22 @@ Entries without port tokens default to DEFAULTPORT."
       (while (search-backward "\\." nil t)
        (delete-char 1)))))
 
+(if (fboundp 'union)
+    (defalias 'gnus-union 'union)
+  (defun gnus-union (l1 l2)
+    "Set union of lists L1 and L2."
+    (cond ((null l1) l2)
+         ((null l2) l1)
+         ((equal l1 l2) l1)
+         (t
+          (or (>= (length l1) (length l2))
+              (setq l1 (prog1 l2 (setq l2 l1))))
+          (while l2
+            (or (member (car l2) l1)
+                (push (car l2) l1))
+            (pop l2))
+          l1))))
+
 (provide 'gnus-util)
 
 ;;; gnus-util.el ends here