bug#32607: 27.0.50; pop-to-buffer in next-error-no-select

[Juri Linkov <juri@linkov.net>]

> The first inhibit-same-window should hopefully make the
> second unnecessary.  If the first fails to do its job or somehow
> indirectly causes the original buffer not to be displayed in the
> original window, I'm not really sure what we should do about it.
> IOW, for the second part I'm not sure either of
> display-buffer-reuse-window or inhibit-same-window is clearly superior
> to the other.
>
> Maybe to get closer to "the ideal", we should go for something like:
>
>     (let* ((orig-window (selected-window))
>            (orig-buf (window-buffer orig-window)))
>       (let ((next-error-highlight next-error-highlight-no-select)
>             (display-buffer-overriding-action '(nil (inhibit-same-window . t))))
>         (next-error n))
>       (cond
>        ((eql (window-buffer orig-window) next-error-last-buffer)
>         ;; inhibit-same-window did its job, we can just return to the original
>         ;; window.
>         (select-window orig-window))
>        ((eql orig-buf next-error-last-buffer)
>         ;; Somehow the original window was affected by `next-error`, so
>         ;; we need to work harder to bring the buffer back.
>         (select-window orig-window)
>         (pop-to-buffer-same-window next-error-last-buffer))
>        (t
>         ;; Something weird is going on.  We don't really know where we were
>         ;; (orig-window was not showing the buffer where we were supposed
>         ;; to "stay"), so let's just try and keep both buffers displayed
>         ;; while at the same time trying not to gratuitously creating new
>         ;; windows either.
>         (let ((display-buffer-overriding-action '(display-buffer-reuse-window
>                                                   (inhibit-same-window . t))))
>           (pop-to-buffer next-error-last-buffer)))))

I see that such explicit handling even supports the case when next-error-last-buffer
gets changed on different frames (when using next-error-buffer-on-selected-frame).

> But maybe we should instead trust inhibit-same-window to do its job and
> go for a simple:
>
>       (save-selected-window
>         (let ((next-error-highlight next-error-highlight-no-select)
>               (display-buffer-overriding-action
>                '(nil (inhibit-same-window . t))))
>           (next-error n)))

This is much simpler.  Actually, this is what I wanted to propose as
a solution to Martin in one of previous messages, but I mistakenly wrote
save-window-excursion whereas I actually intended save-selected-window.