Bug in TRE regular expression library

[Ralf Junker <ralfjunker%gmx.de@localhost>]

I am looking for someone who maintains the NetBSD TRE code in

  http://cvsweb.netbsd.org/bsdweb.cgi/src/external/bsd/tre/

Reason is that I believe that I found a bug in TRE.

Unfortunately, the original TRE author is unresponsive to e-mail
messages. The original TRE mailing lists no longer function, and the
original TRE repository is no longer available. So it seems that the
NetBSD port of TRE might be the only maintaind versioin of TRE - at
least I could find no other.

I am not sure if the problem is relevant to NetBSD, but it might still
be worth reporting. Below follows my message to Ville Laurikari.

Ralf

------

I am using TRE compiled with both TRE_WCHAR and TRE_MULTIBYTE defined.
My build passes all tests fine, except for a "special" case (see code
below).

The special case happens when I set TRE_MB_CUR_MAX = 2 for multi-byte
character support: Then GET_NEXT_WCHAR() no longer advances str_byte at
the end of a null-terminated string.

As a result, the example below does match with TRE_MB_CUR_MAX = 2, which
is *not* correct. With TRE_MB_CUR_MAX = 1 it fails as expected.

A simple fix would be to change tre-match-utils.h line 59 from

  if (w == 0 && len >= 0)

to just

  if (w == 0)

However, I am not sure if this causes any side effects?