Re: Why repository grows after "git gc"? / Purpose of *.keep files?

[Mike Hommey <mh@glandium.org>]

On Mon, May 12, 2008 at 08:12:52PM -0400, Shawn O. Pearce wrote:
> Mike Hommey <mh@glandium.org> wrote:
> > On Mon, May 12, 2008 at 11:03:04PM +0200, Mike Hommey wrote:
> > > On Mon, May 12, 2008 at 11:24:14PM +0300, Teemu Likonen wrote:
> > > > But I have experienced the same earlier with some other post-1.5.5
> > > > version so I believe you can reproduce this yourself. After cloning
> > > > Linus's linux-2.6 repo its .git directory weights 209MB. After single
> > > > "git pull" and "git gc" it was 298MB in my test.
> > > 
> > > I noticed that a while ago: when repacking multiple packs when one has a
> > > .keep file, the resulting additional pack contains too many blobs and
> > > trees, contrary to when only packing loose objects:
> > (...)
> > 
> > That is, it seems to also contain all the blobs and subtrees for all the
> > commits the pack contains, even when they already are in the pack having
> > a .keep file.
> 
> I've noticed this too.  Like since day 1 when we added .keep.
> But uh, nobody else complained and I forgot about it.
> 
> My theory (totally unproven) is that the new pack has objects we
> copied from the .keep pack, because those objects were the best
> delta-bases for the loose objects we have deltafied and want to
> store in the new pack.  Except they aren't yet packed in the new
> pack, so we pack them too.  Tada, duplicates.  :-\

Well, that does not seem delta related, since my testcase doesn't show
deltas in the second pack.

Mike