Strange large push operation.

[Brice Figureau <brice+git@daysofwonder.com>]

Hi,

I'm a git user since about a year, but I can't say I'm really familiar 
with its internals. I am using git v 1.5.6.5

I have a quite large bare remote repository (around 1GiB, about 86k 
objects), and I have a clone on my development computer (which was 
cloned a long time ago). I use ssh to push/pull between those repositories.

About 2 months ago, we created a remote branch (let's call it 'branch') 
and pursued development on this branch and also on master, with a few 
regular merge points from master to 'branch'.

Two days ago, I wanted to start developping a new feature, and as such 
created a local branch from this branch, which we'll call 'newbranch'. I 
cherrypicked a couple of old (4 months) commits  that were in another 
local branch, and then added more small commits (about 10 sloc of 
changes on it) on top of these.

Then I wanted to push this newbranch as a remote branch with:
$ git push origin newbranch:refs/heads/newbranch

and obtained the following output:
Counting objects: 12767, done.
Compressing objects: 100% (3816/3816), done.
writing objects:   8% (935/11682), 2.40 MiB | 324 KiB/s
^C

I stopped the push because I don't get why there are so much objects to 
send while the diff between newbranch and branch is only 5 small commits 
  (and it obviously wants to push a large part of the history).

Is there a way to check what objects are sent to origin and why?
What could be the cause of the issue?
What's wrong with those repositories?

I tried to git gc both repositories, I also git fsck both repositories 
(and found 5 unreachables objects in the local one, should I care?). I 
also upgraded the remote git to latest 1.6.0.6 but this didn't change 
anything. I also tried --thin but that didn't change anything.

So what should I do to push only the changes between branch and newbranch?

Many thanks for any answer,
--
Brice Figureau