bug#67249: 30.0.50; `same-frame` equivalent for `display-buffer-alist`

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

>> BTW, I just noticed another way to attack the problem, which is to add
>> a `pop-up-frames` argument which works just like the variable but takes
>> precedence over it, as in the PoC patch below (a real patch would
>> adjust other places where we use that variable, among other things).
>> WDYT?
> Then we should probably use 'pop-up-windows' instead of
> 'inhibit-same-window'.

Hmm... I don't think it would quite work, because `pop-up-windows`
only controls creation of new windows, whereas `inhibit-same-window`
has an effect in more cases.

> 'display-buffer' resembles a Cervantesque struggle of consistency
> with history.

Indeed.  But I'm not sure how that translates into a practical choice
between `pop-up-frames` and `inhibit-new-frame`.

I'm leaning towards `pop-up-frames` right now because it avoids
introducing a new notion.  Admittedly, the notion it reuses
(i.e. `pop-up-frames`) is not the cleanest around, but
`inhibit-new-frame` isn't super clean either.

Can someone help me choose between those two bad choices?


        Stefan