Rebasing git topic branches

https://github.com/dchelimsky/rspec/wiki/Topic-Branches

 # integrate the latest upstream changes into your "master"

 git checkout master

 git pull 

 # make sure that you're on your topic branch

 git checkout my_topic 

 # do the rebase

 git rebase master

A--B--C--D--E--F

       \

        X--Y--Z

to

 A--B--C--D--E--F

                 \

                  X'--Y'--Z'