HGKeeper

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<title>Code Contributions</title>

<title>Introduction</title>

<para>

All of the Pidgin related projects use

<ulink url="https://reviewboard.org">Review Board</ulink> for handling

contributions at

<ulink url="https://reviews.imfreedom.org">reviews.imfreedom.org</ulink>.

</para>

</sect2>

<title>First Time Setup</title>

<para>

There are a few things you'll need to set up to be able to submit a code

review to these projects. This includes installing

<ulink url="https://www.reviewboard.org/downloads/rbtools/">RBTools</ulink>

as well as some additional

<ulink url="https://www.mercurial-scm.org/">Mercurial</ulink>

configuration.

</para>

<title>Install RBTools</title>

<para>

The recommended way to install RBTools is via pip and can be done with

the following command.

</para>

pip3 install -U "RBTools>=1.0.3"

</programlisting>

<para>

Once RBTools is installed you need to make sure that <code>rbt</code>

is available on your <code>$PATH</code>. To do this, you may need to

add <code>$HOME/.local/bin</code> to your <code>$PATH</code>. The exact

procedure to do this is dependent on your setup and outside of the

scope of this document.

</para>

</sect3>

<title>Mercurial Configuration</title>

<para>

This configuration for Mercurial is to make your life as a contributor

easier. There a few different ways to configure Mercurial, but these

instructions will update your user specific configuration in

<code>$HOME/.hgrc</code>.

</para>

<para>

The first thing we need to do is to install the evolve extension. This

extension makes rewriting history safe and we use it extensively in our

repositories. You can install it with a simple <code>pip3 install -U

hg-evolve</code>. We will enable it below with some other bundled

extensions, but you can find more information about it

<ulink url="https://www.mercurial-scm.org/wiki/EvolveExtension">here</ulink>.

</para>

<para>

When working with Mercurial repositories it is very important to make

sure that your username is set properly as it is added to every commit

you make. To set your username you must add it to the <code>[ui]</code>

section in your <code>$HOME/.hgrc</code> like the following example.

</para>

[ui]

username = Full Name <email@example.com>

</programlisting>

<para>

Next we need to make sure that the <emphasis>evolve</emphasis>

and <emphasis>rebase</emphasis> extensions are loaded. To do so add the

lines in the following example. You do not need to put anything after

the <code>=</code> as this will tell Mercurial to look for them in the

default places for extensions.

</para>

[extensions]

evolve =

rebase =

</programlisting>

<para>

Next we're going to create a <emphasis>revsetalias</emphasis>. This will

be used to make it easier to look at your history and submit your review

request.

</para>

[revsetalias]

wip = only(.,default)

</programlisting>

<para>

This alias will show us just the commits that are on our working branch

and not on the default branch. The default branch is where all

accepted code contributions go. Optionally, you can add the

<code>wip</code> command alias below which will show you the revision

history of what you are working on.

</para>

[alias]

wip = log --graph --rev wip

</programlisting>

<para>

There are quite a few other useful configuration changes you can make,

and a few examples can be found below.

</para>

[ui]

# update a large number of settings for a better user experience, highly

# recommended!!

tweakdefaults = true

[alias]

# make hg log show the graph as well as commit phase

lg = log --graph --template phases

</programlisting>

<para>

Below is all of the above configuration settings to make it easier to

copy/paste.

</para>

[ui]

username = Full Name <email@example.com>

# update a large number of settings for a better user experience, highly

# recommended!!

tweakdefaults = true

[extensions]

evolve =

rebase =

[alias]

# make hg log show the graph as well as commit phase

lg = log --graph --template phases

# show everything between the upstream and your wip

wip = log --graph --rev wip

[revsetalias]

wip = only(.,default)

</programlisting>

</sect3>

<title>Log in to Review Board</title>

<para>

To be able to submit a review request you need to have an account on

our JetBrains Hub instance at

<ulink url="https://hub.imfreedom.org">hub.imfreedom.org</ulink>. You

can create an account here in a number of ways and even turn on two

factor authentication. But please note that if you turn on two factor

authentication you will need to create an application password to be

able to login to Review Board.

</para>

<para>

Once you have that account you can use it to login our Review Board

instance at

<ulink url="https://reviews.imfreedom.org">reviews.imfreedom.org</ulink>.

Please note, you will have to login via the web interface before being

able to use RBTools.

</para>

<para>

Once you have an account and have logged into our Review Board site, you

can begin using RBTools. In your shell, navigate to a Mercurial clone of

one of the Pidgin or purple-related projects, then run the

<code>rbt login</code> command. You should only need to do this once,

unless you change your password or have run the <code>rbt logout</code>

command.

</para>

</sect3>

</sect2>

<title>Creating a New Review Request</title>

<para>

Before starting a new review request, you should make sure that your

local copy of the repository is up to date. To do so, make sure you are

on the <emphasis>default</emphasis> branch via

<code>hg update default</code>. Once you are on the

<emphasis>default</emphasis> branch, you can update your copy with

<code>hg pull --update</code>. Now that you're starting with the most

recent code, you can proceed with your contributions.

</para>

<para>

While it's not mandatory, it is highly recommended that you work on your

contributions via a branch. If you don't go this path, you will have

issues after your review request is merged. This branch name can be

whatever you like as it will not end up in the main repositories, and

you can delete it from your local repository after it is merged. See

</para>

<para>

You can create the branch with the following command:

</para>

hg branch my-new-branch-name

</programlisting>

<para>

Now that you have a branch started, you can go ahead and work like you

normally would, committing your code at logical times, etc. Once you

have some work committed and you are ready to create a new review

request, you can type <code>rbt post wip</code> and you should be good to

go. This will create a new review request using all of the committed work

in your repository and will output something like below.

</para>

Review request #403 posted.

https://reviews.imfreedom.org/r/403/

https://reviews.imfreedom.org/r/403/diff/

</programlisting>

<para>

At this point, your review request has been posted, but it is not yet

published. This means no one can review it yet. To do that, you need to

go to the URL that was output from your <code>rbt post</code> command

and verify that everything looks correct. If this review request fixes

any bugs, please make sure to enter their numbers in the bugs field on

the right. Also, be sure to review the actual diff yourself to make sure

it includes what you intended it to and nothing extra.

</para>

<para>

Once you are happy with the review request, you can hit the publish

button which will make the review request public and alert the reviewers

of its creation. Optionally you can pass <code>--open</code> to

<code>rbt post</code> in the future to automatically open the draft

review in your web browser.

</para>

<para>

<code>rbt post</code> has a ton of options, so be sure to check them out

with <code>rbt post --help</code>. There are even options to

automatically fill out the bugs fixed fields among other things.

</para>

</sect2>

<title>Updating an Existing Review Request</title>

<para>

Typically with a code review, you're going to need to make some updates.

However there's also a good chance that your original branching point

has changed as other contributions are accepted. To deal with this you'll

need to rebase your branch on top of the new changes.

</para>

<para>

Rebasing, as the name suggests is the act of replaying your previous

commits on top of a new base revision. Mercurial makes this pretty easy.

First, make sure you are on your branch with

<code>hg up my-branch-name</code>. Now you can preview the rebase with

<code>hg rebase -d default --keepbranches --dry-run</code>. We prefer

doing a dry-run just to make sure there aren't any major surprises. You

may run into some conflicts, but those will have to be fixed regardless.

</para>

<para>

If everything looks good, you can run the actual rebase with

<code>hg rebase -d default --keepbranches</code>. Again if you run into

any conflicts, you will have to resolve them and they will cause the

dry-run to fail. Once you have fixed the merge conflicts, you'll then

need to mark the files as resolved with

<code>hg resolve --mark filename</code>. When you have resolved all of

the conflicted files you can continue the rebase with

<code>hg rebase --continue</code>. You may run into multiple conflicts,

so just repeat until you're done.

</para>

<para>

After rebasing you can start addressing the comments in your review and

commit them. Once they are committed, you can update your existing

review request with <code>rbt post --update</code>. If for some reason

<code>rbt</code> can not figure out the proper review request to

update, you can pass the number in via

<code>rbt post --review-request-id #</code>. Note that when using

<code>--review-request-id</code> you no longer need to specify

<code>--update</code>.

</para>

<para>

Just like an initial <code>rbt post</code>, the updated version will be

in a draft state until you publish it. So again, you'll need to visit the

URL that was output, verify everything, and click the publish button.

</para>

</sect2>

<title>Landing a Review Request</title>

<para>

This will typically only be done by the Pidgin developers with push

access. If you want to test a patch from a review request, please see the

</para>

<para>

It is <emphasis>HIGHLY</emphasis> recommended that you use a separate

clone of the repository in question when you want to land review requests.

This makes it much easier to avoid accidentally pushing development work

to the canonical repository which makes everyone's life easier. Also, the

mainline repositories now auto publish, so if you do not selectively push

commits, all of your draft commits will be published. You can name this

additional clone whatever you like, but using something like

<code>pidgin-clean</code> is a fairly common practice. This makes it easy

for you to know that this clone is only meant for landing review requests,

and other admistrative work like updating the ChangeLog and COPYRIGHT

files.

</para>

<para>

When you are ready to land a review request you need to make sure you are

on the proper branch. In most cases this will be the branch named

<emphasis>default</emphasis> and can be verified by running the command

<code>hg branch</code>. Next you need to make sure that your local copy

is up to date. You can do this by running <code>hg pull --update</code>.

</para>

<para>

Please note, if you run <code>hg pull</code> and then immediately run

<code>hg pull --update</code> you will <emphasis>not</emphasis> update to

the most recent commit as this new invocation of <code>hg pull</code> has

not actually pulled in any new commits. To properly update, you'll need

to run <code>hg update</code> instead.

</para>

<para>

Once your local copy is up to date you can land the review request with

<code>rbt land --no-push --review-request-id #</code> where <code>#</code>

is the number of the review request you are landing. The

<code>--no-push</code> argument is to disable pushing this commit

immediately. Most of our configuration already enables this flag for you,

but if you're in doubt, please use the <code>--no-push</code> argument.

</para>

<para>

Once the review request has been landed, make sure to verify that the

revision history looks correct, run a test build as well as the unit

tests, and if everything looks good, you can continue with the

housekeeping before we finally push the new commits.

</para>

<para>

The housekeeping we need to do entails a few things. If this is a big new

feature or bug fix, we should be documenting this in the ChangeLog file

for the repository. Please follow the existing convention of mentioning

the contributor as well as the issues addressed and the review request

number. Likewise, if this is someone's first contribution you will need

to add them to the COPYRIGHT file in the repository as well. If you had

to update either of these files, review your changes and commit them

directly.

</para>

<para>

Now that any updates to ChangeLog and COPYRIGHT are completed, we can

actually start pushing the changes back to the canonical repository.

Currently not all of the canonical repositories are publishing

repositories so we'll need to manually mark the commits as public. This

is easily accomplished with <code>hg phase --public</code>.

<emphasis>Note</emphasis>, if you are not using a separate clone of the

canonical repository you will need to specify a revision to avoid

publishing every commit in your repository. If you run into issues or

have more questions about phases see the

<ulink url="https://www.mercurial-scm.org/wiki/Phases">official documentation</ulink>.

</para>

<para>

Now that the changes have been made public, we can finally push to the

canonical repository with <code>hg push</code>. Once that is done, you'll

also need to go and mark the review request as

<emphasis>Submitted</emphasis> in the Review Board web interface.

</para>

</sect2>

<title>Testing Patches Locally</title>

<para>

If you want to test a patch locally for any reason, you first need to

make sure that you are on the target branch for the review request which

is listed on the review request page. In most cases this will be the

<emphasis>default</emphasis> branch. Regardless you'll need to run

<code>hg up branch-name</code> before applying the patch.

</para>

<para>

Now that you are on the correct branch, you can apply the patch with

<code>rbt patch #</code> where <code>#</code> is the id of the review

request you want to test. This will apply the patch from the review

request to your working copy without committing it.

</para>

<para>

Once you're done with your testing you can remove the changes with

<code>hg revert --no-backup --all</code>. This will return your

repository to exactly what it was before the patch was applied. The

<code>--no-backup</code> argument says to not save the changes that you

are reverting and the <code>--all</code> argument tells Mercurial to

revert all files.

</para>

</sect2>

<title>Cleaning up a Landed or Discarded Review Request</title>

<para>

Whether or not your pull request has been accepted, you probably want to

clean it up from your local repository. To do so, you need to update to

a branch other than the branch you built it on. In the following example,

we're going to remove the branch named

<emphasis>my-new-branch-name</emphasis> that we used to create a review

request.

</para>

hg up default

hg prune -r 'branch(my-new-branch-name)'

</programlisting>

<para>

Now, all commits that were on the <emphasis>my-new-branch-name</emphasis>

branch will have their contents removed but interally Mercurial keeps

track that these revisions have been deleted.

</para>

<para>

You can repeat this for any other branches you need to clean up, and

you're done!

</para>

</sect2>

</chapter>

pidgin/pidgin