Resolving a 'both added' merge conflict in git?

I'm rebasing in git, and one conflict I get is 'both added' - that is, exactly the same filename has been added independently in my branch, and in the branch I'm rebasing on. git status tells me:

# Unmerged paths:
#   (use "git reset HEAD <file>..." to unstage)
#   (use "git add/rm <file>..." as appropriate to mark resolution)
#
#       both added:         src/MyFile.cs

My question is, how do I resolve this? Must I use a merge tool or is there a way I can do it just from the commandline? If I git rm src/MyFile.cs, how does git know which file version I want to remove and which I want to keep?

If you use git rm git will remove all versions of that path from the index so your resolve action will leave you without either version.

You can use git checkout --ours src/MyFile.cs to choose the version from the branch onto which you are rebasing or git checkout --theirs src/MyFile.cs to choose the version from the branch which you are rebasing.

If you want a blend you need to use a merge tool or edit it manually.

I sometimes find it confusing using the --theirs and --ours options to identify where the file will come from. Most of the time mine will be in the branch I am rebasing which is referred to by --theirs!

You can also use git checkout <tree-ish> -- src/MyFile.cs

Where the <tree-ish> can be replaced either by the branch name or commit-id that contains the file you wish to keep.

git checkout 6a363d8 -- src/MyFile.cs

git checkout my_branch -- src/MyFile.cs

git checkout HEAD -- src/MyFile.cs

When doing ...

git checkout --ours someFile

It may seem like it didn't do anything when doing git status.

Just Remember to do this afterwards.

git add someFile
git status