Strange perl filter bug

Russ Allbery rra at
Sun Dec 11 20:46:18 UTC 2005

Christoph Biedl <cbiedl at> writes:

> A friend of mine complained that his perl filter (cleanfeed) does not
> catch binaries while other spew is detected, e.g. EMP-md5. After a
> longish debugging session I finally found that the multi-line tests like
> "$hdr{__BODY__} =~ /(...)/m" never match. Reproducing failed: Testing
> the very same data in a standalone perl script was successfull.

> Things are even more strange:
> - System is a Debian sarge Linux, the same problem existed already when
>   it was woody, i.e. different INN version, different Perl version.
> - I could not reproduce this on any other (Debian) system. I assume that
>   there's something specific on that server that even survives upgrades
>   but I have no idea what this might be.
> - Finally: Copying the variable "$BODY = $hdr{__BODY__};" and doing all
>   the tests against $BODY caused the trouble to go away. This is of
>   course a workaround, not a solution.

> Now I ran out of ideas what goes wrong here and how it could be cured.
> Any hint what else I could check?

I have no idea on this.  INN does pull some performance hacks to try to
avoid copying the body of the article, since that produced a noticable
performance gain, so $hdr{__BODY__} is internally special in a way that
the copy of it isn't.  But I have no idea why this would produce those
symptoms, and particularly only on a particular machine.

Russ Allbery (rra at             <>

    Please send questions to the list rather than mailing me directly.
     <> explains why.

More information about the inn-workers mailing list