vimmerge

Wrapper for merging with vim. Handles 2- and 3-way merges, also git merges with RCS conflict markers.

install

Vimmerge is just one script, so you can install by downloading to any directory in the path. For example:

cd /usr/local/bin
sudo curl -O https://raw.githubusercontent.com/agriffis/vimmerge/master/vimmerge
sudo chmod +x vimmerge

usage

git merge

The screencast above demonstrates using vimmerge with git:

git merge branch   # conflicts!
git status         # find a file that's in conflict
vimmerge filename

At this point you have two windows in vim, just as you would have with vimdiff. One window is the conflicts from the merge, the other window is your file. You can use window movement keys and diff commands to resolve the conflicts, then write out your file when you're done.

If you :qa! (quit without writing) then nothing is modified on disk.

git mergetool

Git has a slightly more sophisticated approach to merges using the mergetool command, which automates some of the flow. Vimmerge works well as git mergetool. Here's the config:

git config --global merge.tool vimmerge
git config --global mergetool.vimmerge.cmd 'vimmerge \"$MERGED\"'

You might also want this to avoid .orig files littering your working tree:

git config --global mergetool.keepBackup false

Now when you merge with conflicts, it's a bit more streamlined:

git merge branch  # conflicts!
git mergetool     # runs vimmerge in sequence on conflicting files

As it works without mergetool, you now have two windows in vim. One window is the conflicts from the merge, the other window is your file. You can use window movement keys and diff commands to resolve the conflicts, then write out your file when you're done.

If you :qa! (quit without writing) then nothing is modified on disk.

non-git modes

This script is pretty flexible and varies depending on the command-line arguments. Two-way merges look like this:

vimmerge one two           # same as vimdiff
vimmerge one two -w three  # like vimdiff, with output to new file

Three-way merges are where it gets interesting, because you have a base that's a common ancestor of the conflicting files. By default the file ordering is the same as diff3, but unlike diff3 it saves the results in "mine" by default:

vimmerge mine older yours

To write to a new file, use -w:

vimmerge -w merged mine older yours

You can also use explicit arguments for the files, rather than relying on order:

vimmerge -o older -y yours -m mine -w merged

Some calling programs insist on blindly passing the files in a certain order. You can use --order to work around those:

vimmerge --order oymw older yours mine merged