bug#59862: quit-restore per window buffer

[martin rudalics via "Bug reports for GNU Emacs, the Swiss army knife of text editors" <bug-gnu-emacs@gnu.org>]

 > C-x 5 5   ;; other-frame-prefix
 > C-h i     ;; info
 > q         ;; quit-window
 > This deletes the frame.
 >
 > C-x 5 5   ;; other-frame-prefix
 > C-h i     ;; info
 > C-h e     ;; view-echo-area-messages
 > q         ;; quit-window
 > This doesn't delete the frame because another buffer was used.

Here it doesn't delete the frame because it contains two windows.
'quit-window' deletes the *info* window and the *Messages* window
remains.  When I do C-x o q q instead it first shows the *info* window
only and then deletes the frame just as I would expect.

BTW 'view-echo-area-messages' has a bug: The 'goto-char' moves point in
the *Messages* buffer in an undocumented manner.  It should be written
as:

(defun view-echo-area-messages ()
   "View the log of recent echo-area messages: the `*Messages*' buffer.
The number of messages retained in that buffer is specified by
the variable `message-log-max'."
   (interactive)
   (when-let ((win (display-buffer (messages-buffer))))
     (set-window-point win (point-max))
     win))

 > So frames are handled correctly.  But not tabs:
 >
 > C-x t t   ;; other-tab-prefix
 > C-h i     ;; info
 > q         ;; quit-window
 > This correctly closes the tab.
 >
 > C-x 5 5   ;; other-tab-prefix

I suppose you mean C-x t t here.

 > C-h i     ;; info
 > C-h e     ;; view-echo-area-messages
 > q         ;; quit-window
 > But this also closes the tab, this is a destructive operation,
 > because the user has another buffer shown in the tab.

Here I get two windows.  The 'quit-restore' parameter of the *info*
window is

(tab tab #<window 7 on *info*> #<buffer *info*>)

that of the *Messages* window is

(window window #<window 7 on *info*> #<buffer *Messages*>).

So if I now do q in the *info* window, it will run 'tab-bar-close-tab'.
It's up to that function to DTRT here.

martin