+Advanced Shared Repository Management
+-------------------------------------
+
+Being able to push into a shared repository means being able to
+write into it. If your developers are coming over the network,
+this means you, as the repository administrator, need to give
+each of them an SSH access to the shared repository machine.
+
+In some cases, though, you may not want to give a normal shell
+account to them, but want to restrict them to be able to only
+do `git push` into the repository and nothing else.
+
+You can achieve this by setting the login shell of your
+developers on the shared repository host to `git-shell` program.
+
+[NOTE]
+Most likely you would also need to list `git-shell` program in
+`/etc/shells` file.
+
+This restricts the set of commands that can be run from incoming
+SSH connection for these users to only `receive-pack` and
+`upload-pack`, so the only thing they can do are `git fetch` and
+`git push`.
+
+You still need to create UNIX user accounts for each developer,
+and put them in the same group. Make sure that the repository
+shared among these developers is writable by that group.
+
+. Initializing the shared repository with `git-init-db --shared`
+helps somewhat.
+
+. Run the following in the shared repository:
++
+------------
+$ chgrp -R $group repo.git
+$ find repo.git -type d -print | xargs chmod ug+rwx,g+s
+$ GIT_DIR=repo.git git repo-config core.sharedrepository true
+------------
+
+The above measures make sure that directories lazily created in
+`$GIT_DIR` are writable by group members. You, as the
+repository administrator, are still responsible to make sure
+your developers belong to that shared repository group and set
+their umask to a value no stricter than 027 (i.e. at least allow
+reading and searching by group members).
+
+You can implement finer grained branch policies using update
+hooks. There is a document ("control access to branches") in
+Documentation/howto by Carl Baldwin and JC outlining how to (1)
+limit access to branch per user, (2) forbid overwriting existing
+tags.
+
+
+Bundling your work together
+---------------------------
+
+It is likely that you will be working on more than one thing at
+a time. It is easy to manage those more-or-less independent tasks
+using branches with git.
+
+We have already seen how branches work previously,
+with "fun and work" example using two branches. The idea is the
+same if there are more than two branches. Let's say you started
+out from "master" head, and have some new code in the "master"
+branch, and two independent fixes in the "commit-fix" and
+"diff-fix" branches:
+
+------------
+$ git show-branch
+! [commit-fix] Fix commit message normalization.
+ ! [diff-fix] Fix rename detection.
+ * [master] Release candidate #1
+---
+ + [diff-fix] Fix rename detection.
+ + [diff-fix~1] Better common substring algorithm.
++ [commit-fix] Fix commit message normalization.
+ + [master] Release candidate #1
++++ [diff-fix~2] Pretty-print messages.
+------------
+
+Both fixes are tested well, and at this point, you want to merge
+in both of them. You could merge in 'diff-fix' first and then
+'commit-fix' next, like this:
+
+------------
+$ git merge 'Merge fix in diff-fix' master diff-fix
+$ git merge 'Merge fix in commit-fix' master commit-fix
+------------
+
+Which would result in:
+
+------------
+$ git show-branch
+! [commit-fix] Fix commit message normalization.
+ ! [diff-fix] Fix rename detection.
+ * [master] Merge fix in commit-fix
+---
+ + [master] Merge fix in commit-fix
++ + [commit-fix] Fix commit message normalization.
+ + [master~1] Merge fix in diff-fix
+ ++ [diff-fix] Fix rename detection.
+ ++ [diff-fix~1] Better common substring algorithm.
+ + [master~2] Release candidate #1
++++ [master~3] Pretty-print messages.
+------------
+
+However, there is no particular reason to merge in one branch
+first and the other next, when what you have are a set of truly
+independent changes (if the order mattered, then they are not
+independent by definition). You could instead merge those two
+branches into the current branch at once. First let's undo what
+we just did and start over. We would want to get the master
+branch before these two merges by resetting it to 'master~2':
+
+------------
+$ git reset --hard master~2
+------------
+
+You can make sure 'git show-branch' matches the state before
+those two 'git merge' you just did. Then, instead of running
+two 'git merge' commands in a row, you would pull these two
+branch heads (this is known as 'making an Octopus'):
+
+------------
+$ git pull . commit-fix diff-fix
+$ git show-branch
+! [commit-fix] Fix commit message normalization.
+ ! [diff-fix] Fix rename detection.
+ * [master] Octopus merge of branches 'diff-fix' and 'commit-fix'
+---
+ + [master] Octopus merge of branches 'diff-fix' and 'commit-fix'
++ + [commit-fix] Fix commit message normalization.
+ ++ [diff-fix] Fix rename detection.
+ ++ [diff-fix~1] Better common substring algorithm.
+ + [master~1] Release candidate #1
++++ [master~2] Pretty-print messages.
+------------
+
+Note that you should not do Octopus because you can. An octopus
+is a valid thing to do and often makes it easier to view the
+commit history if you are pulling more than two independent
+changes at the same time. However, if you have merge conflicts
+with any of the branches you are merging in and need to hand
+resolve, that is an indication that the development happened in
+those branches were not independent after all, and you should
+merge two at a time, documenting how you resolved the conflicts,
+and the reason why you preferred changes made in one side over
+the other. Otherwise it would make the project history harder
+to follow, not easier.
+