bug#20845: 25.0.50; bookmark.el, handling of fictitious `buffer' property

[Drew Adams <drew.adams@oracle.com>]

> > I agree, provided the doc of `bookmark-default-handler'
> > makes clear (1) that the value is assumed to be a
> > buffer, not a buffer name,
> 
> The current code accepts both and that seems quite reasonable to me
> (even though I dislike this same fact in many other places).

Yes, right.

> > and (2) that this is not a "normal" bookmark property, that is, one
> > whose value can be saved.
> 
> There's no readable printed representation of a buffer object, so that
> goes without saying.

I don't think it goes without saying, here.
I don't know why we wouldn't want to mention this.

I know of no other possibility of a bookmark that
does not have a print/read representation, and so
can't be persisted.  Persisting bookmarks is a
pretty fundamental part of Emacs bookmarking.

(Even the temporary bookmarks you can create with
Bookmark+ have a print/read representation, so
you can save them if you want.)

Of course, just because I don't know of other
such unsavable bookmarks doesn't mean they aren't
created by some library somewhere.