Re: Bug in looking-at?

[Lennart Borgman]

Lennart Borgman wrote:

> Second time today I think I have found a bug... What should I say... 
> Hope this one is ok ;-)
>
> (defun bug-looking-at()
>  "Instructions for showing the possible bug:
> 1. Place the point before \(interactive\) and run this function.
>   The first looking-at succeeds, the second fails.
> 2. Then copy the last (looking-at ...), place point as before and run 
> with M-S-:.
>   It should fail to match again.
> 3. Now recall this in M-S-: and add character s last in the regexp.
>   This time it should match. Try removing the s again..."
>  (interactive)
>  (unless (looking-at "(interactive)")
>    (error "Please put the point at \(interactive\)"))
>  (message "Second (looking-at ...) => %s" (looking-at 
> "(interactive)[[:space:]]+(unles")))
>
> I am doing this on w32, Emacs from 9 aug, emacs -Q.

Some more information. Looking at the char syntax:

(message "%s,%s,%s"
       (string (char-syntax ?\t))
       (string (char-syntax ?\r))
       (string (char-syntax ?\n)))

gives " ,_,>" -- this is whitespace character, symbol constituent and 
comment ender.

Could part of the problem here be that the syntax table is broken on w32 
since ?\r is symbol constituent? But this can not be the whole story, 
since it behaves differently when run through -S-: