> Am 04.11.2019 um 10:06 schrieb martin rudalics <rudalics@gmx.at>:
> 
> > Suppose, without any display-buffer-alist customization, I have just
> >
> > (setq display-buffer-base-action
> >         (quote (
> >    (display-buffer-reuse-window display-buffer-pop-up-frame)
> >    (reusable-frames . x)
> > )))
> >
> > in my init file, where x can be any of 0,1, nil, visible, all these
> > choices don’t matter for this: If I open Emacs, the initial frame
> > shows up, and any file loaded via recent-files, or by dragging on
> > the Emacs icon, or by clicking on the file icon, shows up in the
> > initial frame, contrary to what is advertised in the
> > manual.
> 
> What _is_ advertised in the manual?

To quote from Section 28.13.5:

Let's consider a user who, as a rule, prefers to display buffers on another frame. Such a user might provide the following customization:
     (customize-set-variable
      'display-buffer-base-action
      '((display-buffer-reuse-window display-buffer-pop-up-frame)
        (reusable-frames . 0)))
This setting will cause display-buffer to first try to find a window showing the buffer on a visible or iconified frame and, if no such frame exists, pop up a new frame.


The words  “another”  and “new”  suggest a behavior different from what I described above.


> 
> > However, once a file is loaded, then re-selecting it via
> > Menu->Buffers, pops it up in a new frame (with properties as
> > specified in defaults-frame-alist). So, what is the relation between
> > "display-buffer-base-action” and “default-frame-alist”?
> 
> If a new frame is created by 'display-buffer', its parameters are
> determined by
> 
> (1) any 'pop-up-frame-parameters' entry found,
> 
> (2) the value of 'pop-up-frame-alist' (if the function specified by
>    'pop-up-frame-function' processes it - the default does) and
> 
> (3) the value of 'default-frame-alist'.
> 
> So if you use the 'display-buffer-base-action' specification from the
> top, only 'default-frame-alist' will be used because you neither
> customized any 'pop-up-frame-parameters' nor 'pop-up-frame-alist' (the
> latter should not be used anyway).  All based on the assumption that
> you have customized 'switch-to-buffer-obey-display-actions' so that
> Menu->Buffers indeed tries to pop to the buffer.
> 
> martin
>