+(defcustom gnus-subthread-sort-functions 'gnus-thread-sort-functions
+ "*List of functions used for sorting subthreads in the summary buffer.
+By default, subthreads are sorted the same as threads, i.e.,
+according to the value of `gnus-thread-sort-functions'."
+ :group 'gnus-summary-sort
+ :type '(choice
+ (const :tag "Sort subthreads like threads" gnus-thread-sort-functions)
+ (repeat
+ (gnus-widget-reversible
+ (choice (function-item gnus-thread-sort-by-number)
+ (function-item gnus-thread-sort-by-author)
+ (function-item gnus-thread-sort-by-recipient)
+ (function-item gnus-thread-sort-by-subject)
+ (function-item gnus-thread-sort-by-date)
+ (function-item gnus-thread-sort-by-score)
+ (function-item gnus-thread-sort-by-most-recent-number)
+ (function-item gnus-thread-sort-by-most-recent-date)
+ (function-item gnus-thread-sort-by-random)
+ (function-item gnus-thread-sort-by-total-score)
+ (function :tag "other"))
+ (boolean :tag "Reverse order")))))
+