Overwrite everything in master with another branch in git

Question

I have a very out of date master branch in a git repository.

All of my work has been done in another branch.

What is the best way to merge the two?

I don't care about anything in master, it is way out of date.

Answer 1

If you are fine with losing the history of your master branch you just let master point to the head of your current branch (your don't "overwrite" master - the branch - per se):

git checkout yourotherbranch
git branch -D master
git checkout -b master

Of course if you have a remote clone, you'll then have to

git push -f origin master 

Nota bene: this specifically applies to replacing the whole of your master branch and throwing the old master away as the title suggests. Otherwise, you should be fine with git merge master --strategy=ours.

Answer 2

Let's assume your work is in a branch called dev:

git checkout dev 
git merge --strategy=ours master
git checkout master 
git merge dev

The merge option --strategy=ours is meant to be used to supersede old development history of side branches (quote).