Error during redisplay: (error No match 3 in highlight (3 (quote (7))))

Error during redisplay: (error No match 3 in highlight (3 (quote (7))))

[Lennart Borgman]

I just got an error report for nXhtml where the error in the subject
line happens. This is in a buffer with multiple major modes (using
mumamo.el) so it is not an Emacs bug. I just do not understand what
the error mean. Can someone please shed some light upon it?

Re: Error during redisplay: (error No match 3 in highlight (3 (quote (7))))

[Andreas Schwab]

Lennart Borgman <lennart.borgman@gmail.com> writes:

> I just do not understand what the error mean. Can someone please shed
> some light upon it?

It means that a font-lock pattern referenced a subexp of a regexp that
does not exist or did not match, i.e. (match-beginning 3) returned nil.

Andreas.

-- 
Andreas Schwab, schwab@linux-m68k.org
GPG Key fingerprint = 58CA 54C7 6D53 942B 1756  01D3 44D5 214B 8276 4ED5
"And now for something completely different."

Re: Error during redisplay: (error No match 3 in highlight (3 (quote (7))))

[Stefan Monnier]

>> I just do not understand what the error mean. Can someone please shed
>> some light upon it?
> It means that a font-lock pattern referenced a subexp of a regexp that
> does not exist or did not match, i.e. (match-beginning 3) returned nil.

Exactly.  And the (7) indicates it's probably one of the rules in
font-lock-syntactic-keywords rather than in font-lock-keywords.  i.e. it
either means one of the rules in font-lock-syntactic-keywords is using
the wrong group number, or it needs to be tweaked to set the
LAXMATCH option.


        Stefan

Re: Error during redisplay: (error No match 3 in highlight (3 (quote (7))))

[Lennart Borgman]

On Sun, May 10, 2009 at 9:25 PM, Stefan Monnier
<monnier@iro.umontreal.ca> wrote:
>>> I just do not understand what the error mean. Can someone please shed
>>> some light upon it?
>> It means that a font-lock pattern referenced a subexp of a regexp that
>> does not exist or did not match, i.e. (match-beginning 3) returned nil.
>
> Exactly.  And the (7) indicates it's probably one of the rules in
> font-lock-syntactic-keywords rather than in font-lock-keywords.  i.e. it
> either means one of the rules in font-lock-syntactic-keywords is using
> the wrong group number, or it needs to be tweaked to set the
> LAXMATCH option.

Thanks, that cleared my thoughts enough. The problem was that I had
forgot to add save-match-data when I rearranged some code in
mumamo.el. (Calls to chunk dividing routines is done from the
font-lock machinery.)