Just use git pull to pull the remote branch into master:
git remote add something git://host.example.com/path/to/repo.git
git checkout master
git pull something master
Or do it without adding a remote:
git pull git://host.example.com/path/to/repo.git
git pull fetches the remote branch, and merges it into the local branch. If possible, it does a fast-forward merge, which just means that it updates the current master to the latest commit without generating a merge commit. But if there are changes on both sides, it will do a merge, like the ones you see Linus and Junio doing, with the remote URL included.
If you want to guarantee that you get a merge commit, even if it could fast forward, do git pull -no-ff. If you want to make sure that pull never creates a merge commit (so fails if there are changes on both sides), do git pull --ff-only.
If you want to include a more detailed message, like the full log that Linus provides, do git pull --log. If you want to edit the message, instead of just using the automatically created message, use git pull --edit. See documentation for git pull for more options.