[PATCH] fix sambaundoguidindex

[Rowland Penny]

On Tue, 12 Feb 2019 09:06:23 +1300
Andrew Bartlett via samba-technical <samba-technical at lists.samba.org>
wrote:

> On Sat, 2019-02-09 at 12:08 +0100, Björn JACKE via samba-technical
> wrote:
> > can I get a 2nd revewer for this fix please?
> > 
> > This bug can prevent people to go back to a non-guid index samba
> > version. Along with
> > https://bugzilla.samba.org/show_bug.cgi?id=13760 (update to 4.9
> > without going via a 4.8 release is broken) this is a bit nasty as
> > users might get stuck with a non-downgradable database and a broken
> > 4.9 samba setup.
> 
> The patch is fine, but it needs what I didn't do when I added it
> (sorry!) and a test, so we don't screw it up again.  
> 
> A shell or python blackbox test should be enough, using tdbdump or tdb
> python bindings to look for GUID or DN based record keys to see which
> mode we are in.
> 
> > Also, does someone have an idea about the root cause of
> > https://bugzilla.samba.org/show_bug.cgi?id=13760
> > This bug will badly hit ad-dc users of those distributions which
> > skip the 4.8 release.
> 
> This is really strange.  Have you managed to work out what 4.8 does
> that 4.9 doesn't do?  I'm not aware of anything intentional, so this
> needs some solid investigation.  
> 
> Do you get this generically, or only on some specific databases?

It seems to be generic, easy to reproduce, find a Samba machine that is
running 4.7.x, upgrade it to 4.9.x and the problem will hit you, only
way to fix it, downgrade again.
If you upgrade to 4.8.x and then to 4.9.x, it works, so it probably has
something to do with the GUID code that went in at 4.8.0, but this is
just a guess.

Rowland

> 
> Thank you so much for looking into this.
> 
> Andrew Bartlett
>