Possible regexp bug in org.el

Possible regexp bug in org.el

[Thorsten Jolitz]

Hi List, 

here is a possible regexp bug in org.el I discovered by accident:

,---------------------------------------------
| 7734:       (and (not (looking-back "^\*+"))
`---------------------------------------------

#+begin_src emacs-lisp
(and (not (looking-back "^\*+")) ; missing backslash?
 (looking-at "[ \t]+") (replace-match ""))
(unless (eobp) (forward-char 1))
(when (looking-at "^\\*")
#+end_src

-- 
cheers,
Thorsten

Re: Possible regexp bug in org.el

[Nicolas Richard]

Thorsten Jolitz <tjolitz@gmail.com> writes:
> here is a possible regexp bug in org.el I discovered by accident:
>
> ,---------------------------------------------
> | 7734:       (and (not (looking-back "^\*+"))
> `---------------------------------------------

It's almost certainly a typo, but it introduces no bug because '*' can't
bear its special meaning after '^', so the regexp engine will make it
match exactly the '*' character. But it'd be better written as "^*+"
(but this is not recommended) or, preferably, "^\\*+" indeed.

Here's the relevant manual excerpt from (info "(elisp) Regexp Special") :

>    *Please note:* For historical compatibility, special characters are
> treated as ordinary ones if they are in contexts where their special
> meanings make no sense.  For example, `*foo' treats `*' as ordinary
> since there is no preceding expression on which the `*' can act.  It is
> poor practice to depend on this behavior; quote the special character
> anyway, regardless of where it appears.

-- 
Nico.

Re: Possible regexp bug in org.el

[Bastien]

Hi Thorsten and Nicolas,

Nicolas Richard <theonewiththeevillook@yahoo.fr> writes:

> It's almost certainly a typo, but it introduces no bug because '*' can't
> bear its special meaning after '^', so the regexp engine will make it
> match exactly the '*' character. But it'd be better written as "^*+"
> (but this is not recommended) or, preferably, "^\\*+" indeed.

Fixed in master, thanks,

-- 
 Bastien