Git: getting changes from another branch

git checkout featurebranch && git rebase master

As long as you haven't pushed yet, it is better to replay your changes on top of master.

See:

• git rebase vs. merge
• git workflow and rebase vs merge questions

git checkout featurebranch && git merge master

You can do this as many times as you like; it won't affect master and you will be able to easily do it the other way around whenever you find out you are done with the feature branch.