When you have a PR which has been here for some times, and master is very active, you will end up have lots of commits in your history when you get the changes from master.
To clean this up:
git fetch origin
: get the latest from the repogit checkout my_branch
: go to your branch for pull requestgit rebase origin/master
: this will rebase the current branch with mastergit push -f
: force push, as we are rewriting history