Re: Starting to think about sha-256?

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Aug 28, 2006, 23:09 UTC
Message-ID: <Pine.LNX.4.63.0608290101320.28360@wbgn013.biozentrum.uni-wuerzburg.de>
In-Reply-To: <Pine.LNX.4.64.0608281034440.27779@g5.osdl.org>

Hi,

On Mon, 28 Aug 2006, Linus Torvalds wrote:

Show 12 quoted lines

> 
> 
> On Mon, 28 Aug 2006, David Lang wrote:
> > 
> > just to double check.
> > 
> > if you already have a file A in git with hash X is there any condition where a
> > remote file with hash X (but different contents) would overwrite the local
> > version?
> 
> Nope. If it has the same SHA1, it means that when we receive the object 
> from the other end, we will _not_ overwrite the object we already have.

The only notable exception I can think of: "git fetch -k". If you then try to retrieve the bogus object, it will return the one of whichever pack was returned first be readdir(). (If I read the source correctly.)

Now, the cases are rare where you do both "git fetch -k" and "git repack -a -d" (the latter of which _could_ leave a hole in the directory which _could_ make the next fetched pack fill that hole, which in turn _could_ make readdir() return that pack before more "senior" packs) in the same repository, but in these cases, yes, you could end up with the copy of the remote side.

You'd need to explicitely use "git fetch -k", though.

Ciao, Dscho