Discussion on: Git merge specific file from another branch

What this does is replace a file on a branch with the file from the other branch.The actual solution would look like this:

Say I had a file1.txt in branch B I wanted to merge with a file1.txt in branch A.

git checkout A

git checkout --patch B file1.txt

1.First, get yourself to branch A(Where you want to do the merge).
2.Patch with the file from branch B.

If your file1.txt does not exist in branch A , leave out the option --patch.
Note that once this command is run, you can accept options that will be provided in the terminal. You can choose to accept with the y or regect with n and so on