git How to merge a branch into the master branch by completely overwriting master branch

Question

I started work on the master branch. Almost one year ago, I created another branch dev in which I made some changes. From that time on I continued work on dev branch. Now I want to merge dev into master which results in lot of conflicts. I want to merge dev into master by overwriting master branch's contents i.e. for any conflict that arises I want to keep dev branch's version of the code. How can it be done ?

Answer 1

You can specify the strategy option with -X switch:

git checkout master
git merge -X theirs dev

A bit explanation. The -X theirs means: Use recursive strategy with the merge but fallback to their changes if the strategy cannot resolve the conflict.

This is different from -s ours (for some reason there's no -s theirs) which would be a greedy take ours always solution to conflicts.

git-merge(1) Merge Strategies section provides a deeper explanation on this.

Answer 2

You'll want to use a "merge using theirs" strategy, which is set using the -X flag

git checkout master
git merge -X theirs dev