Re: [Emacs-diffs] /srv/bzr/emacs/trunk r109890: Do not mark objects from deleted buffers, windows and frames.

[Stefan Monnier]

>   Do not mark objects from deleted buffers, windows and frames.

I'm not sure this is safe.  Such deleted objects are still perfectly
live from the memory-allocation point of view, and while some operations
on them are disallowed "for ever", there are others that might still be
permitted and which may still access internal data.

E.g. you might still be able to get (window|frame)-parameters of
a deleted (window|frame).

IOW, it adds lines of code, makes the invariants more complex (in ways
which I'm not sure is currently ensured by the rest of the code) and the
benefits aren't obvious at all.

I don't think scanning those objects can take a noticeable amount of
time, so the only potential issue is holding on to data that can never
be used again, in which case I'd much prefer changing
kill-buffer/delete-(window|frame) so they set the various fields to
NULL/nil.  Which is a much safer change.


        Stefan