Weird growth in packfile during initial push

I was doing a more recent conversion of the Gentoo repo, and ran into some odd behavior in the packfile size.

For anybody else following the repo, you can now get it on the new hardware at: http://git-exp.overlays.gentoo.org/gitweb/?p=exp/gentoo-x86.git;a=summary

I did the conversion with cvs2svn, packed, added the remote and pushed, only to find that the pack on the remote side suddenly seemed to be ~60MiB larger.

$ time git repack -adf --window=250 --depth=250 real 19m59.339s user 96m48.011s sys 0m36.914s

$ ls -la /tmp/convert/gentoo-x86-cvs2git/.git/objects/pack total 903804 drwxr-xr-x 2 robbat2 users 119 Apr 14 08:05 . drwxr-xr-x 4 robbat2 users 28 Apr 14 08:05 .. -r--r--r-- 1 robbat2 users 139155472 Apr 14 08:05 pack-f805bb448f864becfeac9c7f8a8ac2ef90c26787.idx -r--r--r-- 1 robbat2 users 786336481 Apr 14 08:05 pack-f805bb448f864becfeac9c7f8a8ac2ef90c26787.pack

$ git remote add origin git+ssh://git@git-exp.overlays.gentoo.org/exp/gentoo-x86.git
$ git push origin master:master
Initialized empty Git repository in /var/gitroot/exp/gentoo-x86.git/
Counting objects: 4969800, done.
Delta compression using up to 8 threads.
Compressing objects: 100% (1217809/1217809), done.
Writing objects: 100% (4969800/4969800), 810.56 MiB | 21608 KiB/s, done.
Total 4969800 (delta 3735812), reused 4969800 (delta 3735812)
To git+ssh://git@git-exp.overlays.gentoo.org/exp/gentoo-x86.git
 * [new branch]      master -> master

$ ls -la /var/gitroot/exp/gentoo-x86.git/objects/pack total 966876 drwxr-xr-x 2 git git 4096 Apr 14 08:43 . drwxr-xr-x 4 git git 4096 Apr 14 08:35 .. -r--r--r-- 1 git git 139155472 Apr 14 08:43 pack-f805bb448f864becfeac9c7f8a8ac2ef90c26787.idx -r--r--r-- 1 git git 849936308 Apr 14 08:43 pack-f805bb448f864becfeac9c7f8a8ac2ef90c26787.pack

On the client side after the initial clone, it DOES match (in size) what was cloned.

(If you're looking for the 849MB one right now, I'll have to get it back for you, I wanted to save that extra space so just did an rsync of the other pack over the too-large one for now).