Fix updating buffer menu after invoking "M-x term"

The doc string of 'frame-or-buffer-changed-p' says not to call it
with the nil argument, but term.el did.  Since "M-x term" puts
'term--update-term-menu' on the 'menu-bar-update-hook' ahead of
'menu-bar-update-buffers', it caused the latter decide that there
was no change in buffers, because the internal state variable
used by 'frame-or-buffer-changed-p' when called with the nil
argument was reset by 'term--update-term-menu'.  Fix that by using
a non-nil state variable.
* lisp/term.el (term--buffers-changed): New variable.
(term--update-term-menu): Use it when calling
'frame-or-buffer-changed-p'.  (Bug#80231)

1 files changed, 3 insertions, 1 deletions

diff --git a/lisp/term.el b/lisp/term.el
index 34b3450624c..9ac77730350 100644
--- a/lisp/term.el
+++ b/lisp/term.el
@@ -1009,9 +1009,11 @@ For custom keybindings purposes please note there is also
     ["Paging" term-pager-toggle :style toggle :selected term-pager-count
      :help "Toggle paging feature"]))
 
+(defvar term--buffers-changed nil)
+
 (defun term--update-term-menu (&optional force)
   (when (and (lookup-key term-mode-map [menu-bar terminal])
-             (or force (frame-or-buffer-changed-p)))
+             (or force (frame-or-buffer-changed-p 'term--buffers-changed)))
     (let ((buffer-list (match-buffers '(derived-mode . term-mode))))
       (easy-menu-change
        nil