Re: `save-excursion' defeated by `set-buffer'

[Andreas Röhler]

Am 11.03.2011 02:28, schrieb Stefan Monnier:
> > > The difference between save-excursion and save-current-buffer is that
> > > the first doesn't just save&restore the current buffer but also "point&
> > > mark".  But if you do `set-buffer' right after save-excursion then most
> > > likely you will change neither point nor mark in the original buffer, so
> > > the extra work performed by save-excursion compared to
> > > save-current-buffer will be useless.
> > > Now that's just a waste of resources but is otherwise harmless.
> > >
> > > Unless of course `blub' is already the current buffer to start with.
> > >
> > > I.e. whether point movement in "..." is undone by save-excursion will
> > > depend dynamically upon whether the current buffer happens to be `blub',
> > > which leads to subtle bugs.  Hence the warning.
>
> > Thanks, this warning goes away if body is wrapped with a let:
>
> > (save-excursion
> >    (let ()
> >      (set-buffer blub)
> >        ...
> >        ))
>
> I see you apparently didn't understand much of what I wrote :-(
>
>
>          Stefan

Maybe let's put the question another way:

is there an example, where save-excursion will fail, ie not restore the 
buffer due to a set-buffer afterwards?

Thanks

Andreas