An efficient built-in mapcan

[gnu-emacs] / lisp / gnus / gnus-sum.el

diff --git a/lisp/gnus/gnus-sum.el b/lisp/gnus/gnus-sum.el
index a81a4e24c41f852c050b50a89dccea3d36172b09..910c796915aef5c42e7e808639109e12274215fe 100644 (file)
--- a/lisp/gnus/gnus-sum.el
+++ b/lisp/gnus/gnus-sum.el
@@ -4749,7 +4749,7 @@ If LINE, insert the rebuilt thread starting on line LINE."
 (defun gnus-articles-in-thread (thread)
   "Return the list of articles in THREAD."
   (cons (mail-header-number (car thread))
-       (apply 'nconc (mapcar 'gnus-articles-in-thread (cdr thread)))))
+       (mapcan 'gnus-articles-in-thread (cdr thread))))
 
 (defun gnus-remove-thread (id &optional dont-remove)
   "Remove the thread that has ID in it."