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

[Drew Adams]

> > +** New 'pop-up-frames' action alist entry for 'display-buffer'.
> > +This has the same effect as the variable of the same name and takes
> >                                  ^^^^^^^^
> > +precedence over the variable when present.
> >
> > Please don't do that.  This is a user option,
> > _not_ just a variable.  (And yes, it should
> > continue to be supported, forever, regardless
> > of the fact that it's been "deprecated".)
> >
> > `display-buffer' shouldn't override the user's
> > choice for the behavior.
> 
> There's nothing wrong with having parameters and user options by the
> same name that affect the same functionality, but indeed usually the
> user option overrides the parameter, not the other way around.  See,
> for example, the cursor-type option and frame parameter.

Exactly.