I have made a git repository and added a text file to it. This is 100% for learning purpose.
You will have a conflict if you merge:
That is because:
master(with a second line empty)
branch3(with a second line including "3")
master(with a second line including "2", from the merge of
Git will ask you to choose which content to keep ("3", "2", or both).
First, do the merges after:
git config merge.conflictstyle diff3
See "Fix merge conflicts in Git?".