Make the recency sorting stable when we have inverted sorting

* lisp/ibuffer.el (recency): Remove.
(recency): New macro function so that sorting by recency is
stable when inverted sorting is switched on (bug#30129).

1 files changed, 7 insertions, 11 deletions

diff --git a/lisp/ibuffer.el b/lisp/ibuffer.el
index 84c53b16acf..c91a70b3a1c 100644
--- a/lisp/ibuffer.el
+++ b/lisp/ibuffer.el
@@ -219,7 +219,6 @@ view of the buffers."
                  (const :tag "File name" :value filename/process)
                  (const :tag "Major mode" :value major-mode)))
 (defvar ibuffer-sorting-mode nil)
-(defvar ibuffer-last-sorting-mode nil)
 
 (defcustom ibuffer-default-sorting-reversep nil
   "If non-nil, reverse the default sorting order."
@@ -2129,16 +2128,13 @@ the value of point at the beginning of the line for that buffer."
            (and ibuffer-buf
                 (not (eq ibuffer-buf buf))))))
 
-;; This function is a special case; it's not defined by
-;; `define-ibuffer-sorter'.
-(defun ibuffer-do-sort-by-recency ()
-  "Sort the buffers by last view time."
-  (interactive)
-  (setq ibuffer-sorting-mode 'recency)
-  (when (eq ibuffer-last-sorting-mode 'recency)
-    (setq ibuffer-sorting-reversep (not ibuffer-sorting-reversep)))
-  (ibuffer-update nil t)
-  (setq ibuffer-last-sorting-mode 'recency))
+(define-ibuffer-sorter recency
+ "Sort the buffers by how recently they've been used."
+  (:description "recency")
+  (time-less-p (with-current-buffer (car b)
+                 (or buffer-display-time 0))
+               (with-current-buffer (car a)
+                 (or buffer-display-time 0))))
 
 (defun ibuffer-update-format ()
   (when (null ibuffer-current-format)