fix bug#39344

* gnus.el (gnus-add-buffer): Use `cl-pushnew' instead of `push' to
  avoid duplicate entries.

diff --git a/lisp/gnus/gnus.el b/lisp/gnus/gnus.el
index 6df26b4af8c1eecba9a3af2aee4eab52826a9f21..caeab7f55af469ac2201a9c39f4b8b4d35a03250 100644 (file)
--- a/lisp/gnus/gnus.el
+++ b/lisp/gnus/gnus.el
@@ -660,7 +660,7 @@ be used directly.")
 (defun gnus-add-buffer ()
   "Add the current buffer to the list of Gnus buffers."
   (gnus-prune-buffers)
-  (push (current-buffer) gnus-buffers))
+  (cl-pushnew (current-buffer) gnus-buffers))
 
 (defmacro gnus-kill-buffer (buffer)
   "Kill BUFFER and remove from the list of Gnus buffers."