Re: thing-at-point's meaning of current sexp vs. up-list's: which is correct?

[Kelly Dean]

Stefan Monnier wrote:
>I think the bug is in kill-backward-up-list.  `up-list' is definitely
>behaving correctly here, and thing-at-point is basically free to return
>anything it feels like (it's a very ad-hoc function which tries to
>DWIM).

forward-sexp and er/expand-region agree with up-list's meaning, and it does 
look like the right meaning. If thing-at-point is ad-hoc DWIM anyway, then I 
don't see the advantage of it using a different meaning than the standard for 
other functions. Wouldn't it be better to change thing-at-point? Besides this, 
in trunk, thing-at-point returns nil in the case I described, even though there 
certainly is a sexp at point, so that bug might as well be fixed in a way that 
makes thing-at-point compatible with the other functions.
And kill-backward-up-list's implementation is short and elegant; dealing with 
thing-at-point's different meaning would make it longer and ugly.