Funny repack behaviour

Hi,

I just accidentally reran "git-repack -a -d" on a repository, where I just had run it. And I noticed a funny thing: Of about 4000 objects, it reused all but 8. So I reran it, and it reused all but 2. I ran it once again, and it reused all.

The really funny thing is: it created the same pack every time!

It is not critical, evidently, but I'd like to know what is causing this rather undeterministic behaviour. (Before you ask: no, I did not make a backup before running the tests, so I unfortunately cannot reproduce it).

Ciao, Dscho

P.S.: This is the output:

$ git-repack -a -d
Generating pack...
Done counting 4259 objects.
Deltifying 4259 objects.
 100% (4259/4259) done
Writing 4259 objects.
 100% (4259/4259) done
Total 4259, written 4259 (delta 3391), reused 4241 (delta 3379)
Pack pack-66bd976bbdc2ac6da623b8af02037218ecd72ef0 created.
$ git-repack -a -d
Generating pack...
Done counting 4259 objects.
Deltifying 4259 objects.
 100% (4259/4259) done
Writing 4259 objects.
 100% (4259/4259) done
Total 4259, written 4259 (delta 3393), reused 4257 (delta 3391)
Pack pack-66bd976bbdc2ac6da623b8af02037218ecd72ef0 created.
$ git-repack -a -d
Generating pack...
Done counting 4259 objects.
Deltifying 4259 objects.
 100% (4259/4259) done
Writing 4259 objects.
 100% (4259/4259) done
Total 4259, written 4259 (delta 3393), reused 4259 (delta 3393)
Pack pack-66bd976bbdc2ac6da623b8af02037218ecd72ef0 created.