bug#8667: 24.0.50; `bounds-of-thing-at-point' returns (N . N) for `comment'

[Stefan Monnier]

> (Dunno why some people insist on using `(if (and...) singleton)'.

Probably because those people find it better communicates the intent.

> And it seems that `forward-comment' is otherwise buggy, in that it moves only
> over whitespace when point is within a comment.

Not only over whitespace: also over a nested comment.
What would you want it to do instead?  Jump to the end of the comment?
Kind of like an `up-comment'?

The forward-<thingy> functions all share the following property AFAIK:
when called with a positive argument with point *before* some
<thingies>, they will skip over that many <thingies> and when called
with a negative argument with point *after* some <thingies> they will
skip over that many <thingies>.

E.g. just like forward-comment, forward-sexp from within a sexp will not
skip to the end of that sexp.  And just like forward-sexp,
forward-comment called in front of a nested comment will jump over that
nested comment.

All calls with point elsewhere than before/after a <thingy> behave in
somewhat arbitrary ways which mostly depend on how the function is
implemented and what kind of structure <thingies> have (e.g. can they
nest?  Can we easily tell when we're in the middle of a <thingy>?).


        Stefan