[Samba] Error running "samba-tool dbcheck" after going from 4.8.6 to 4.9.2

[Andrew Bartlett]

On Fri, 2018-11-09 at 11:46 +0300, Taner Tas via samba wrote:
> > I just tested Samba 4.9.2 on one of my DCs, previously running
> > version 4.8.6. Immediately after install, I ran "samba-tool dbcheck"
> > and got the following:
> > 
> > Checking 511 objects
> > ERROR(<type 'exceptions.UnicodeDecodeError'>): uncaught exception - 
> > 'ascii' codec can't decode byte 0xc3 in position 25: ordinal not in 
> > range(128)
> >    File 
> > "/usr/local/samba/lib64/python2.7/site-packages/samba/netcmd/__init__.py", 
> > line 177, in _run
> >      return self.run(*args, **kwargs)
> >    File 
> > "/usr/local/samba/lib64/python2.7/site-packages/samba/netcmd/dbcheck.py", 
> > line 157, in run
> >      controls=controls, attrs=attrs)
> >    File 
> > "/usr/local/samba/lib64/python2.7/site-packages/samba/dbchecker.py", 
> > line 222, in check_database
> >      error_count += self.check_object(object.dn, attrs=attrs)
> >    File 
> > "/usr/local/samba/lib64/python2.7/site-packages/samba/dbchecker.py", 
> > line 2315, in check_object
> >      expected_dn = ldb.Dn(self.samdb, "RDN=RDN,%s" % (parent_dn))
> > 
> > 
> > The error disappears after going back to Samba 4.8.6. The underlying
> > OS is CentOS 7.4.
> > 
> > Although the names my users use at logon don't have accented
> > characters, several of them have them in their complete names.
> > Several of the group names also have accented characters.
> > 
> > This is likely the same error reported under Bug 13616, which
> > meanwhile has been declared as closed.
> > https://bugzilla.samba.org/show_bug.cgi?id=13616
> > 
> 
> The bugfix seems applied to ldb version 1.4.3 so samba should recompile
> against ldb-1.4.3 regardless any samba-4.9 version.

Thankfully we enforce the reverse (that samba 4.9.2 requires ldb 1.4.3)
pretty strongly. 

What is being seen here is another manifestation of the same issue,
that is as we migrated parts of Samba to building and running with
python3, the distinction between string and unicode has become more
important.  

Noel has been handling this and I'm sure we can sort it out.

Andrew Bartlett

-- 
Andrew Bartlett                       http://samba.org/~abartlet/
Authentication Developer, Samba Team  http://samba.org
Samba Developer, Catalyst IT          http://catalyst.net.nz/services/samba