bug#51883: 29.0.50; Command to get accidentally deleted frames back

[martin rudalics]

> Which other parameters would you suggest to remove (on master)?

It would be pretentious to answer that question.  The comment starting
at line 261 of frameset.el tells that

;; - `window-id', `outer-window-id', `parent-id': They are assigned
;;   automatically and cannot be set, so keeping them is harmless, but they
;;   add clutter.  `window-system' is similar: it's assigned at frame
;;   creation, and does not serve any useful purpose later.

so according to that comment, leaving 'parent-id' in the list should not
have caused any problems.  Thanks to Juri, we know better now.

For anyone who wants to peruse the parameters of an existing frame,
however, reading the ";; Filtering" comment in frameset.el should be an
indispensable prerequisite.  Juanma (and maybe others) have invested a
lot of work there - consider entries on 'frameset--text-pixel-height' or
'minibuffer'.  Disregarding that text when implementing a function that
pretends to clone a frame is just recklessness.

martin