From mboxrd@z Thu Jan  1 00:00:00 1970
From: Timo Teras <timo.teras@iki.fi>
Subject: Re: git fast-import: how to prevent incremental commit with no
 changes
Date: Wed, 7 May 2014 08:01:37 +0300
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To: Junio C Hamano <gitster@pobox.com>
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On Tue, 06 May 2014 12:18:16 -0700
Junio C Hamano <gitster@pobox.com> wrote:

> Timo Teras <timo.teras@iki.fi> writes:
> 
> > I'm trying to script a setup that would periodically import a
> > tarball to git with fast-import. But things do not always change,
> > so I'd like fast-import to be able to not do the commit in case
> > there is no change.
> >
> > That is, I'm constructing the commit with "deleteall" + importing
> > each object by mark after that. Now, in case nothing changed,
> > fast-import will happily create an empty commit for me.
> >
> > Would it be possible to add some flag that would make commit fail in
> > case nothing changed?
> >
> > Any suggestions how to do this?
> 
> I am not sure if such a conditional logically belongs to what
> fast-import does.  Would it be an option for your script to rewind
> the HEAD after the import is done and it finds that the tarball did
> not have anything interesting new?

Yes, this is what I ended up with for now. I wanted to avoid this mostly
so that I would not need to run "git gc --prune=now" or similar after
each import (or at least not "often").

Thanks.