bug#716: Bug in buffer-swap-text

[jasonr@f2s.com]

Quoting Stefan Monnier <monnier@IRO.UMontreal.CA>:

> > I can reliably get a crash without changing coding systems:
> > (progn
> >   (buffer-swap-text (generate-new-buffer "test"))
> >   (insert (make-string 128 ?a)))

I get a crash at this point using C-x C-e on this line as the first activity in
emacs -Q, after pasting the above into *scratch* and removing the > quotations.

> > (progn
> >   (buffer-swap-text (generate-new-buffer "test"))
> >   (garbage-collect))
>
> I cannot seem to reproduce it here, tho I'm not 100% sure how you run
> the above code.  Could you give a more detailed recipe, starting from
> "emacs -Q" and showing whether you use M-: or C-x C-e, ... ?

Can you reproduce it by evaluating the following first:

(set-default-coding-systems 'iso-latin-1-dos)

Possibly not, as setting the coding systems to ...-unix does not make the
problem go away for me, and the user who saw the bug on NetBSD/powerpc did not
report doing anything special like this to trigger the bug.