bug#15133: 24.3.50; REGRESSION: `after-make-frame-functions' now run with wrong frame selected

[Drew Adams]

>  > This regression was introduced after a build from 2013-08-08.  It
>  > appears in the build cited below, from 2013-08-18.  It makes Emacs
>  > unusable (by me).
>  >
>  > I have this as `after-make-frame-functions': `(fit-frame)', in order to
>  > fit the new frame to its displayed buffer.'
>  >
>  > When `after-make-frame-functions' is run in `make-frame' now, the
>  > original frame, not the newly created frame, is selected when it runs.
>  > So `fit-frame' is called with the original (wrong) frame selected.
> 
> If it can be fixed by commenting in the second line of the following
> comment in `pop-to-buffer'
> 
>    ;; This should be done by `select-window' below.
>    ;; (set-buffer buffer)
> 
> we have the following problem: Your `fit-frame' will work when using
> `pop-to-buffer' but not when using `display-buffer'.  So maybe it's
> better to do the funcall in `display-buffer-pop-up-frame' as
> 
>              (with-current-buffer buffer
>                (setq frame (funcall fun)))
> 
> Please try them both, tell me whether they work for you, and, if so,
> which one you prefer.

Sorry, I don't understand.  What "both" would you like me to try?  This
needs to work as it did before the regression - both `pop-to-buffer'
and `display-buffer'.

But first, I don't understand either why there should be any difference.
Why shouldn't functions on `after-make-frame-functions' always be passed
the new frame as argument, as has been the case in the past?  There is a
`before-make-frame-functions' hook for passing the originally selected
frame.

Perhaps you are thinking that this is about _selecting_ the new frame?
(I mistakenly mentioned "is selected" above, when I meant is passed to
the hook functions.)

I can understand that `pop-to-buffer' and `display-buffer' might act
differently wrt selecting the buffer's frame.  But I do not understand
why suddenly the functions on hook `after-make-frame-functions' should
be passed the original frame as arg instead of the new frame.

How else can someone invoke a function on the new frame as part of the
process of frame creation?