bug#71386: 29.1; Frame is auto-deleted even when it has multiple tabs

[Eli Zaretskii <eliz@gnu.org>]

> From: Al Haji-Ali <abdo.haji.ali@gmail.com>
> Date: Thu, 06 Jun 2024 00:44:28 +0100
> 
> 
> If I open a frame with multiple tabs, and one of the tabs has a dedicated window, then kill the buffer with the dedicated window, the frame is deleted along with its tabs.
> 
> I understand that this is the documented behaviour, however my expectation is that the tab should be deleted but the frame should stay when other tabs are available, similar to how the frame is not deleted if other windows are visible.

I'm not sure I agree with you.  Tabs are just saved frame
configurations, they are not real windows.  If we make this behavior
dependent on tab-bar-mode, we basically introduce an incompatible
behavior change in this particular case, which people and Lisp
programs out there might not expect or like.

I'm adding Juri and Martin to this discussion.

> The following code illustrates the issue:
> 
> ,----
> | (with-selected-frame (make-frame)
> |     (tab-bar-mode)
> |     (switch-to-buffer (generate-new-buffer "test"))
> |     (tab-bar-new-tab)
> |     (switch-to-buffer (generate-new-buffer "test2"))
> |     (set-window-dedicated-p (selected-window) t)
> |     ;;(kill-buffer)  ;; Kill buffer manually to see the issue
> | )
> `----
> 
> I am unable to test this on Emacs 30, but I checked the source code and `window--delete` in `window.el`, which is the function that I think should be changed, seems to do the same as in Emacs 29.1.

Emacs 30 behaves the same in this regard.