Created branch from feature01 instead of master

WhatChaGonnaDo

sitting on feature01 - all commited, no changes
started to work another problem
better create a branch for this
 - git branch -b feature02
whoops sitting on feature02 with some new changes that I really wanted based on master instead of feature01

... something-something profit ...

Assuming you're on feature02 and you've commited (or stashed) all WIP, this will replay all commits since feature01 starting from `master instead:

git rebase --onto master feature01

Or if you haven't done any work at all on feature02, you can just git reset --hard master to move the branch pointer (and reset the working copy) to match master.