git doesn't seem to pull all updates - HEAD and origin/HEAD in different positions

Question

I have ended up with a git repository in a state I don't know how to handle, and I need some help with understanding a) what's going on, how and why the repository is in this state, and b) how I should react to it. Basically, when pulling from the remote, I end up ahead of the remote, even if I reset all changes and try again.

This is what I've done:

I have forked a git repository, cloned the upstream version (which I don't have write access to) and then added my own fork to the list of remotes, so that git remote -v shows the following:

$ git remote -v
mine    [email protected]:tlycken/julia.git (fetch)
mine    [email protected]:tlycken/julia.git (push)
origin  git://github.com/JuliaLang/julia.git (fetch)
origin  git://github.com/JuliaLang/julia.git (push)

I now want to make sure that my local version is up to date with everything in the upstream repo, so I run

$ git pull origin master
From git://github.com/JuliaLang/julia
 * branch            master     -> FETCH_HEAD
Already up-to-date.
tlycken$ git status
# On branch master
# Your branch is ahead of 'origin/master' by 4 commits.
#   (use "git push" to publish your local commits)
#
nothing to commit, working directory clean

This confuses me. Why is my branch ahead of origin master? I haven't changed anything.

To see if I could do something about it, I ran git lg (an alias for git log --graph with some prettyprint). The top of the output looks like this:

*   6912a42 - (HEAD, mine/master, master) Merge pull request #3052 from daviddelaat/linalgnumber (2013-05-10 11:23:09 -0700) <Viral B. Shah>
|\  
| * 8116d51 - Use Number instead of Integer in some linalg operations (2013-05-10 19:12:45 +0200) <David de Laat>
* | 6cc1532 - Update .travis.yml configuration in the manual. (2013-05-10 21:41:59 +0530) <Viral B. Shah>
* | fa1e3fe - Update logdet. Close #3070. (2013-05-10 19:35:37 +0530) <Viral B. Shah>
* |   a182f7f - (origin/master, origin/HEAD, mine/contrib-base) Merge branch 'master' of github.com:JuliaLang/julia (2013-05-10 03:10:38 -0400) <Jeff Bezanson>

Apparently, the HEAD's are in different positions. To make sure that I get the correct code in my local repository before I start branching out, I did git reset --hard origin/HEAD to remove anything I was ahead, and then git pull origin master to make sure I was up to date (i.e. didn't reset too far or something):

$ git pull origin master
From git://github.com/JuliaLang/julia
 * branch            master     -> FETCH_HEAD
Updating a182f7f..6912a42
Fast-forward
 base/linalg/dense.jl         |  2 +-
 base/linalg/factorization.jl | 44 ++++++++++++++++++++++----------------------
 doc/manual/packages.rst      |  3 +--
 3 files changed, 24 insertions(+), 25 deletions(-)
$ git status
# On branch master
# Your branch is ahead of 'origin/master' by 4 commits.
#   (use "git push" to publish your local commits)
#
nothing to commit, working directory clean

and I'm back where I started.

What is going on here? What should I do to get to a state where my local master has the latest updates from upstream?

Answer 1

git pull doesn't update your tracking refs (origin/...) that keep track of where various remotes' HEADs are.

Run git fetch origin and it'll update all of the origin/... tracking refs and git status will no longer think you're ahead.

---

git pull <remote> <branch> is the equivalent of:

1. git fetch <remote> <branch>:FETCH_HEAD
2. git merge FETCH_HEAD

Because it explicitly specifies only the one branch to fetch, and fetches it into the special local ref FETCH_HEAD, it doesn't update anything else locally - only FETCH_HEAD and the branch you're pulling into.

Running git fetch <remote> instead will update all of the refs associated with that remote repository.