<title>Private Branches</title>

By default, everything you check into a Fossil repository is shared
to all clones of that repository.  In Fossil, you don't push and pull
individual branches; you push and pull everything all at once.

But sometimes users want to keep some private work that is not
shared with others.  This might be a preliminary or experimental change
that needs further refinement before it is shared and which might never
be shared at all.  To do this in Fossil, simply commit the change with
the --private command-line option:

<pre>
fossil commit --private
</pre>

The --private option causes Fossil to put the check-in in a new branch
named "private".  That branch will not participate in subsequent clone,
sync, push, or pull operations.  The branch will remain on the one local
repository where it was created.  Note that you only use the --private
option for the first check-in that creates the private branch.
Additional checkins into the private branch remain private automatically.

<h2>Publishing Private Changes</h2>

After additional work, one might desire to publish the changes associated
with a private branch.  The usual way to do this is to merge those
changes into a public branch.  For example:

<pre>
fossil update trunk
fossil merge private
fossil commit
</pre>

The private branch remains private and is not recorded as a parent
in the merge manifest's P-card, but all of the changes associated with
the private branch are now folded into the public branch and are hence
visible to other users of the project.

A private branch created with Fossil version 1.30 or newer can also be
converted into a public branch using the <code>fossil publish</code>
command.  However, there is no way to convert a private branch created with
older versions of Fossil into a public branch.

<div class="sidebar">
To avoid generating a missing artifact
reference on peer repositories without the private branch, the merge parent
is not recorded when merging the private branch into a public branch.  As a
consequence, the web UI timeline does not draw a merge line from the private
merge parent to the public merge child.  Moreover, repeat private-to-public
merge operations (without the [/help?cmd=merge | --force option]) with files
added on the private branch may only work once, but later abort with
"WARNING: no common ancestor for FILE", as the parent-child relationship is
not recorded. (See the [/doc/trunk/www/branching.wiki | Branching, Forking,
Merging, and Tagging] document for more information.)
</div>

The <code>--integrate</code> option of <code>fossil merge</code> (to close
the merged branch when committing) is ignored for a private branch -- or the
check-in manifest of the resulting merge child would include a
<code>+close</code> tag referring to the leaf check-in on the private branch,
and generate a missing artifact reference on repository clones without that
private branch.  It's still possible to close the leaf of the private branch
(after committing the merge child) with the <code>fossil amend --close</code>
command.

<h2>Syncing Private Branches</h2>

A private branch normally stays on the one repository where it was
originally created.  But sometimes you want to share private branches
with another repository.  For example, you might be building a cross-platform
application and have separate repositories on your Windows laptop,
your Linux desktop, and your iMac.  You can transfer private branches
between these machines by using the --private option on the "sync",
"push", "pull", and "clone" commands.  For example, if you are running
"fossil server" on your Linux box and you want to clone that repository
to your Mac, including all private branches, use:

<verbatim>
fossil clone --private http://user@linux.localnetwork:8080/ mac-clone.fossil
</verbatim>

You'll have to supply a username and password in order for this to work.
Fossil will not clone (or sync) private branches anonymously.

By default, there are no users that can do private branch syncing.  You
will have to give a user
the "Private" capability ("x") if you want them to be able to do this.
We deny such capability for normal users by default to add a barrier to
accidental syncing of a private branch to a public server. It is highly recommended that
you leave the "x" capability turned off on all repositories used for
collaboration (repositories to which many people push and pull) and
only enable "x" for local repositories when you need to share private
branches.

Private branch sync only works if you use the --private command-line option.
Private branches are never synced via the auto-sync mechanism.  Once
again, this restriction is designed to make it hard to accidentally
push private branches beyond their intended audience.

<h2>Purging Private Branches</h2>

You can remove all private branches from a repository using this command:

<pre>
fossil scrub --private
</pre>

Note that the above is a permanent and irreversible change.  You will
be asked to confirm before continuing.  Once the private branches are
removed, they cannot be retrieved (unless you have synced them to another
repository.)  So be careful with the command.

<h2>Additional Notes</h2>

All of the features above apply to <u>all</u> private branches in a
single repository at once.  There is no mechanism in Fossil (currently)
that allows you to push, pull, clone, sync, or scrub an individual
private branch within a repository that contains multiple private
branches.
