bug#15998: 24.3; forward-sexp (scan-sexps) doesn't do well with some SEXPs

[Noam Postavsky]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>>> No, but I think syntax-propertize can take care of those things.
>> The patch below seems to work, no new sexp movement commands needed?
>
> It should work indeed, tho I'm not sure it'll fix the original problem,
> because I don't know *where* the original problem happened and this
> patch only fixes the case where we do such navigation in
> emacs-lisp-mode, but things #s(...) and #&"..." are *very* rare in
> those buffers.

I tend to end up with those things in my *scratch* buffer, after
evaluating various expressions (more so the #s(...) than #&"...", I
don't have much call for messing with bool vectors).  Michael bumped
into an instance of ## in org-list.el (see merged Bug#30132), although
that seems like a mistake in org.

> So I'm not completely sure the cost imposed by this patch is worth
> the benefit.

On the benefit side, it would allow removing the hack I put in for
indentation of #s(...) (that was for IELM, see Bug#31984).  On the other
hand, this seems to be breaking some edebug tests, so that needs more
investigation before it could be installed.