From: Levin Du <zslevin@gmail.com>
Date: Mon, 07 Sep 2015 03:51:52 GMT
Subject: Re: Questions about git-push for huge repositories
Message-ID: <CAN6cQGNGP+n3L=tuRCymOTWFCnFNsq-tFHkaNm+W=o726mjmmw@mail.gmail.com>
In-Reply-To: <CAN6cQGMf089ERn2kZbFpHJ6vyJ4BnjCm-m-E+hQsduH55XFvKw@mail.gmail.com>

I try to use 'git replace --graft' to work aroud this. Here's the process:
  cd A
  fetch ../B master:master_b
  git replace --graft master_b master_a
  # now master_b's parent is master_a

  # do a filter-branch to make the stone solid
  git filter-branch --tag-name-filter cat -- master_a..master_b

  # prune all the old refs and do gc
  git replace -d <origin_commit_of_master_b>
  git update-ref -d refs/original/refs/heads/master_b
  git reflog expire --expire=now --all
  git gc --prune=now --aggressive

And I'd like to make master_b look orphan, so using 'git replace' again:
   git replace --graft master_b
   git log master_b
   # only show one commit, fine
   git push /path/to/public/A master_b
   # small amount of data pushed
   du -hs  /path/to/public/A
   # 6.2 GiB

All are fine, except when I want to push the replace ref:
   git push /path/to/public/A 'refs/replace/*'

It pushes 6 GiB data again.

So right now, 'git replace --graft master_b' needs to run by users
if they need a tidy history view.