Mercurial: The Definitive Guide

Sharing Changes

I mentioned earlier that repositories in Mercurial are self-contained. This means that the changeset we just created exists only in our my-hello repository. Let’s look at a few ways that we can propagate this change into other repositories.

Pulling Changes from Another Repository

To get started, let’s clone our original hello repository, which does not contain the change we just committed. We’ll call our temporary repository hello-pull:

$ cd ..
$ hg clone hello hello-pull
updating working directory
2 files updated, 0 files merged, 0 files removed, 0 files unresolved

We’ll use the hg pull command to bring changes from my-hello into hello-pull. However, blindly pulling unknown changes into a repository is a somewhat scary prospect. Mercurial provides the hg incoming command to tell us what changes the hg pull command would pull into the repository, without actually pulling the changes in:

$ cd hello-pull
$ hg incoming ../my-hello
comparing with ../my-hello
searching for changes
changeset:   5:12efb75cbece
tag:         tip
user:        Bryan O'Sullivan <[e-mail]>
date:        Tue May 05 06:44:49 2009 +0000
summary:     Added an extra line of output

Bringing changes into a repository is a simple matter of running the hg pull command, and optionally telling it which repository to pull from:

$ hg tip
changeset:   4:2278160e78d4
tag:         tip
user:        Bryan O'Sullivan <[e-mail]>
date:        Sat Aug 16 22:16:53 2008 +0200
summary:     Trim comments.

$ hg pull ../my-hello pulling from ../my-hello searching ...