Re: Prefer to split along the longest edge

[martin rudalics]

> It could be both.  But I firmly object to make this be customizable
> _only_ through display-buffer action alists, because that is even less
> user-friendly than function values of defcustoms.

If we make this and other display buffer options a defcustom too, we'd
have to specify the semantics of that defcustom.  In particular:

- Should the defcustom hold for any buffer to be displayed?

- Should it override what the calling program specifies in the ALIST
  argument.

- Would a 'display-buffer-alist' entry override it?

Once these have been resolved, we can easily add defcustoms for most
options that are currently only available via 'display-buffer-alist'.

martin