Mercurial: The Definitive Guide

Don’t Repeat Yourself: Merging Across Branches

In many cases, if you have a bug to fix on a maintenance branch, the chances are good that the bug exists on your project’s main branch (and possibly other maintenance branches, too). It’s a rare developer who wants to fix the same bug multiple times, so let’s look at a few ways that Mercurial can help you to manage these bug fixes without duplicating your work.

In the simplest instance, all you need to do is pull changes from your maintenance branch into your local clone of the target branch.

$ cd ..
$ hg clone myproject myproject-merge
updating working directory
3 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd myproject-merge
$ hg pull ../myproject-1.0.1
pulling from ../myproject-1.0.1
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
(run 'hg heads' to see heads, 'hg merge' to merge)

You’ll then need to merge the heads of the two branches, and push back to the main branch.

$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg commit -m 'Merge bugfix from 1.0.1 branch'
$ hg push
pushing to /tmp/branch-repo8ztZpS/myproject
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files