git local remote base merge

http://stackoverflow.com/questions/5440610/git-and-difftool-problems-what-do-local-and-remote-point-to

there are 4 components to this (note that before this step, you would have already done a local-checkin.)

The local-checkin that your git tree has: LOCAL
The head of the remote repository (that is going to be merged): REMOTE
common ancestor to both LOCAL and REMOTE: BASE
The file that will be written as a result: MERGED.