Re: svn clone Checksum mismatch question

From: Eric Wong <normalperson@yhbt.net>
Date: Mar 29, 2009, 06:08 UTC
Message-ID: <20090329060858.GB15773@dcvr.yhbt.net>
In-Reply-To: <83dfc36c0903270418q59a81290xcb8043b8c037be18@mail.gmail.com>

Anton Gyllenberg <anton@iki.fi> wrote:

> I hope I didn't hijack the thread with an unrelated issue.

No worries if you did. You helped me find a stupid bug in git-svn that's been there for 3 years. I couldn't help the original poster at all since he was working on a private repo and I can't support git-svn under Windows.

Show 24 quoted lines

> 2009/3/26 Anton Gyllenberg <anton@iki.fi>:
> > I don't know if this is the same issue, but the I get a similar error
> > on the public twisted-python repository on both windows and linux,
> > with several different versions and plenty of free disk space. As this
> > is a publicly accessible repository it should be easy to reproduce:
> >
> > git svn init -s svn://svn.twistedmatrix.com/svn/Twisted twisted
> > cd twisted
> > git svn fetch -r 13611:HEAD
> >
> > This ultimately dies with the following error:
> > W: +empty_dir: trunk/doc/core/howto/listings/finger/finger
> > r13612 = f6d995ac255e3dfa08a517a6e72fbcfe63feaaa0 (trunk)
> > Checksum mismatch:
> > branches/foom/--omg-optimized/twisted/internet/cdefer/cdefer.pyx
> > 264b0c5f7b3a00d401d1a5dcce67a3734f0eede3
> > expected: c7ccddd195f132926e20bab573da7ef3
> >     got: f006323ff4714ca52c0228ce6390d415
> 
> is branches/foom/--omg-optimized (like with the branch name being
> foom/--omg-optimized), not just branches/foom. Is think git-svn relies
> on the standard layout being branches directly under the branches/
> directory, but I don't see how this would get the paths mixed up like
> this.

Root problem: I misused "git ls-tree" for 3 years and nobody noticed. At least I'm glad the checksum verification every step of the way caught this bug and prevented propagating it into repository corruption.

Show 7 quoted lines

> Looking at what was done around this commit one finds odd stuff, like
> deleting directories in trunk and then copying from a previous
> revision of trunk to under the branch:
> http://twistedmatrix.com/trac/changeset/13611
> 
> I created a local test svn repository and tried to do something
> similar but git-svn had no problem with my test.

I was fooled by the weird copy sequences, too.

> This is issue is not critical for me in any way but if somebody wants
> to look into it I am happy to help out.

I guess few folks in the UNIX world are crazy enough to make pathnames prefixed with dashes :) But I do wonder how/if many repositories out there failed and nobody bothered to report it...

Patch in reply

-- 
Eric Wong