Diff for "MergingWithVim"

Using Vim as a merge program for Mercurial

Vim's diff mode (aka "vimdiff") allows vim to be used to do hg merges.

Here's my favorite way to use vim to do mercurial merges.

Configuration: In your ~/.hgrc file, add the following:

[ui]
merge = vimdiff

[merge-tools]
vimdiff.executable = vim
vimdiff.args = -d $base $local $output $other +close +close

The 'args' command opens all 4 version of 'file': 'file~base' = common ancestor, 'file.orig' = local tree's version, 'file' = merge result (i.e. resolve your conflicts into this file: it's the one that hg considers the 'fixed' version when you're done), and 'file~other' = version from the other tree, that you're merging from. Since you are typically most interested in the 'file' and 'file~other' buffers (and since vim's keyboard shortcuts for :diffget ("do") and :diffput ("dp") only work when two buffers are open), we close the windows for the other two buffers. They're still around, though: if the merge is complex and you want to see them, use :bnext/:bprev.

If you are unfamiliar with vim's diff mode, you may find ":help diff" useful to read (see in particular the ":diffget" and ":diffput" commands). Also, diff mode by default uses folds, so "help folding" may be useful.

If things go terribly wrong: quit vim via ":cq". It won't save, and will return an error code, so mercurial will not consider the file merged yet, and you can try again via "hg resolve filename" (hg resolve -l to see list of files, in case you get really confused). If you decide you hate using vimdiff, for instance, you can ":cq", set 'ui.merge = internal:merge" in your .hgrc, and run resolve, and you'll be back to merging via "<<<<<<<" and ">>>>>>>" marks in the file. So you can try vimdiff out as a merge tool without getting into a world of pain if you don't like/understand it.

There has been some confusion about using Vim's DirDiff extension to do hg merges. DirDiff can be used for fancy "hg diff" browsing (a great way to look at patches), but will not work with "hg merge".

See 'man hgrc' for a full explanation of configuring hgrc files