:linkattrs:
= User Guide

This is a Gerrit guide that is dedicated to Gerrit end-users. It
explains the standard Gerrit workflows and how a user can adapt Gerrit
to personal preferences.

It is expected that readers know about link:http://git-scm.com/[Git,role=external,window=_blank]
and that they are familiar with basic git commands and workflows.

[[gerrit]]
== What is Gerrit?

Gerrit is a Git server that provides link:access-control.html[access
control] for the hosted Git repositories and a web front-end for doing
link:#code-review[code review]. Code review is a core functionality of
Gerrit, but still it is optional and teams can decide to
link:#no-code-review[work without code review].

[[tools]]
== Tools

Gerrit uses the git protocol. This means in order to work with Gerrit
you do *not* need to install any Gerrit client, but having a regular
git client, such as the link:http://git-scm.com/[git command line,role=external,window=_blank] or
link:http://eclipse.org/egit/[EGit,role=external,window=_blank] in Eclipse, is sufficient.

Still there are some client-side tools for Gerrit, which can be used
optionally:

* link:http://eclipse.org/mylyn/[Mylyn Gerrit Connector,role=external,window=_blank]: Gerrit
  integration with Mylyn
* link:https://github.com/uwolfer/gerrit-intellij-plugin[Gerrit
  IntelliJ Plugin,role=external,window=_blank]: Gerrit integration with the
  link:http://www.jetbrains.com/idea/[IntelliJ Platform,role=external,window=_blank]
* link:https://play.google.com/store/apps/details?id=com.jbirdvegas.mgerrit[
  mGerrit,role=external,window=_blank]: Android client for Gerrit
* link:https://github.com/stackforge/gertty[Gertty,role=external,window=_blank]: Console-based
  interface for Gerrit

[[clone]]
== Clone Gerrit Project

Cloning a Gerrit project is done the same way as cloning any other git
repository by using the `git clone` command.

.Clone Gerrit Project
----
  $ git clone ssh://gerrithost:29418/RecipeBook.git RecipeBook
  Cloning into RecipeBook...
----

The URL for cloning the project can be found in the Gerrit web UI
under `Projects` > `List` > <project-name> > `General`.

For git operations Gerrit supports the link:user-upload.html#ssh[SSH]
and the link:user-upload.html#http[HTTP/HTTPS] protocols.

[NOTE]
To use SSH you may need to link:user-upload.html#ssh[configure your SSH public
key in your `Settings`].

[[code-review]]
== Code Review Workflow

With Gerrit _Code Review_ means to link:#review-change[review] every
commit *before* it is accepted into the code base. The author of a code
modification link:user-upload.html#push_create[uploads a commit] as a
change to Gerrit. In Gerrit each change is stored in a
link:#change-ref[staging area] where it can be checked and reviewed.
Only when it is approved and submitted it gets applied to the code
base. If there is feedback on a change, the author can improve the code
modification by link:#upload-patch-set[amending the commit and
uploading the new commit as a new patch set]. This way a change is
improved iteratively and it is applied to the code base only when is
ready.

[[upload-change]]
== Upload a Change

Uploading a change to Gerrit is done by pushing a commit to Gerrit. The
commit must be pushed to a ref in the `refs/for/` namespace which
defines the target branch: `refs/for/<target-branch>`.
The magic `refs/for/` prefix allows Gerrit to differentiate commits
that are pushed for review from commits that are pushed directly into
the repository, bypassing code review. For the target branch it is
sufficient to specify the short name, e.g. `master`, but you can also
specify the fully qualified branch name, e.g. `refs/heads/master`.

.Push for Code Review
----
  $ git commit
  $ git push origin HEAD:refs/for/master

  // this is the same as:
  $ git commit
  $ git push origin HEAD:refs/for/refs/heads/master
----

.Push with bypassing Code Review
----
  $ git commit
  $ git push origin HEAD:master

  // this is the same as:
  $ git commit
  $ git push origin HEAD:refs/heads/master
----

[[push-fails]]
[NOTE]
If pushing to Gerrit fails consult the Gerrit documentation that
explains the link:error-messages.html[error messages].

[[change-ref]]
When a commit is pushed for review, Gerrit stores it in a staging area
which is a branch in the special `refs/changes/` namespace. Understanding
the format of this ref is not required for working with Gerrit, but it
is explained below.

A change ref has the format `refs/changes/X/Y/Z` where `X` is the last
two digits of the change number, `Y` is the entire change number, and `Z`
is the patch set. For example, if the change number is
link:https://gerrit-review.googlesource.com/c/gerrit/+/263270[263270,role=external,window=_blank],
the ref would be `refs/changes/70/263270/2` for the second patch set.

[[fetch-change]]
Using the change ref git clients can fetch the corresponding commit,
e.g. for local verification.

.Fetch Change
----
  $ git fetch https://gerrithost/myProject refs/changes/74/67374/2 && git checkout FETCH_HEAD
----

[NOTE]
The fetch command can be copied from the
link:user-review-ui.html#download[download commands] in the change
screen.

The `refs/for/` prefix is used to map the Gerrit concept of
"Pushing for Review" to the git protocol. For the git client it looks
like every push goes to the same branch, e.g. `refs/for/master` but in
fact for each commit that is pushed to this ref Gerrit creates a new
branch under the `refs/changes/` namespace. In addition Gerrit creates
an open change.

[[change]]
A change consists of a link:user-changeid.html[Change-Id], meta data
(owner, project, target branch etc.), one or more patch sets, comments
and votes. A patch set is a git commit. Each patch set in a change
represents a new version of the change and replaces the previous patch
set. Only the latest patch set is relevant. This means all failed
iterations of a change will never be applied to the target branch, but
only the last patch set that is approved is integrated.

[[change-id]]
The Change-Id is important for Gerrit to know whether a commit that is
pushed for code review should create a new change or whether it should
create a new patch set for an existing change.

The Change-Id is a SHA-1 that is prefixed with an uppercase `I`. It is
specified as footer in the commit message (last paragraph):

----
  Improve foo widget by attaching a bar.

  We want a bar, because it improves the foo by providing more
  wizbangery to the dowhatimeanery.

  Bug: #42
  Change-Id: Ic8aaa0728a43936cd4c6e1ed590e01ba8f0fbf5b
  Signed-off-by: A. U. Thor <author@example.com>
----

If a commit that has a Change-Id in its commit message is pushed for
review, Gerrit checks if a change with this Change-Id already exists
for this project and target branch, and if yes, Gerrit creates a new
patch set for this change. If not, a new change with the given
Change-Id is created.

If a commit without Change-Id is pushed for review, Gerrit creates a
new change and generates a Change-Id for it. Since in this case the
Change-Id is not included in the commit message, it must be manually
inserted when a new patch set should be uploaded. Most projects already
link:project-configuration.html#require-change-id[require a Change-Id]
when pushing the very first patch set. This reduces the risk of
accidentally creating a new change instead of uploading a new patch
set. Any push without Change-Id then fails with
link:error-missing-changeid.html[missing Change-Id in commit message
footer].

Amending and rebasing a commit preserves the Change-Id so that the new
commit automatically becomes a new patch set of the existing change,
when it is pushed for review.

.Push new Patch Set
----
  $ git commit --amend
  $ git push origin HEAD:refs/for/master
----

Change-Ids are unique for a branch of a project. E.g. commits that fix
the same issue in different branches should have the same Change-Id,
which happens automatically if a commit is cherry-picked to another
branch. This way you can link:user-search.html[search] by the Change-Id
in the Gerrit web UI to find a fix in all branches.

Change-Ids can be created automatically by installing the `commit-msg`
hook as described in the link:user-changeid.html#creation[Change-Id
documentation].

Instead of manually installing the `commit-msg` hook for each git
repository, you can copy it into the
link:http://git-scm.com/docs/git-init#_template_directory[git template
directory,role=external,window=_blank]. Then it is automatically copied to every newly cloned
repository.

[[review-change]]
== Review Change

After link:#upload-change[uploading a change for review] reviewers can
inspect it via the Gerrit web UI. Reviewers can see the code delta and
link:user-review-ui.html#inline-comments[comment directly in the code]
on code blocks or lines. They can also link:user-review-ui.html#reply[
post summary comments and vote on review labels]. The
link:user-review-ui.html[documentation of the review UI] explains the
screens and controls for doing code reviews.

There are several options to control how patch diffs should be
rendered. Users can configure their preferences in the
link:user-review-ui.html#diff-preferences[diff preferences].

[[upload-patch-set]]
== Upload a new Patch Set

If there is feedback from code review and a change should be improved a
new patch set with the reworked code should be uploaded.

This is done by amending the commit of the last patch set. If needed
this commit can be fetched from Gerrit by using the fetch command from
the link:user-review-ui.html#download[download commands] in the change
screen.

It is important that the commit message contains the
link:user-changeid.html[Change-Id] of the change that should be updated
as a footer (last paragraph). Normally the commit message already
contains the correct Change-Id and the Change-Id is preserved when the
commit is amended.

.Push Patch Set
----
  // fetch and checkout the change
  // (checkout command copied from change screen)
  $ git fetch https://gerrithost/myProject refs/changes/74/67374/2 && git checkout FETCH_HEAD

  // rework the change
  $ git add <path-of-reworked-file>
  ...

  // amend commit
  $ git commit --amend

  // push patch set
  $ git push origin HEAD:refs/for/master
----

[NOTE]
Never amend a commit that is already part of a central branch.

Pushing a new patch set triggers email notification to the reviewers.

[[multiple-features]]
== Developing multiple Features in parallel

Code review takes time, which can be used by the change author to
implement other features. Each feature should be implemented in its own
local feature branch that is based on the current HEAD of the target
branch. This way there is no dependency to open changes and new
features can be reviewed and applied independently. If wanted, it is
also possible to base a new feature on an open change. This will create
a dependency between the changes in Gerrit and each change can only be
applied if all its predecessor are applied as well. Dependencies
between changes can be seen from the
link:user-review-ui.html#related-changes-tab[Related Changes] tab on
the change screen.

[[watch]]
== Watching Projects

To get to know about new changes you can link:user-notify.html#user[
watch the projects] that you are interested in. For watched projects
Gerrit sends you email notifications when a change is uploaded or
modified. You can decide on which events you want to be notified and
you can filter the notifications by using link:user-search.html[change
search expressions]. For example '+branch:master file:^.*\.txt$+' would
send you email notifications only for changes in the master branch that
touch a 'txt' file.

It is common that the members of a project team watch their own
projects and then pick the changes that are interesting to them for
review.

Project owners may also configure
link:intro-project-owner.html#notifications[notifications on
project-level].

[[adding-reviewers]]
== Adding Reviewers

In the link:user-review-ui.html#reviewers[change screen] reviewers can
be added explicitly to a change. The added reviewer will then be
notified by email about the review request.

Mainly this functionality is used to request the review of specific
person who is known to be an expert in the modified code or who is a
stakeholder of the implemented feature. Normally it is not needed to
explicitly add reviewers on every change, but you rather rely on the
project team to watch their project and to process the incoming changes
by importance, interest, time etc.

There are also link:intro-project-owner.html#reviewers[plugins which
can add reviewers automatically] (e.g. by configuration or based on git
blame annotations). If this functionality is required it should be
discussed with the project owners and the Gerrit administrators.

[[dashboards]]
== Dashboards

Gerrit supports a wide range of link:user-search.html#search-operators[
query operators] to search for changes by different criteria, e.g. by
status, change owner, votes etc.

The page that shows the results of a change query has the change query
contained in its URL. This means you can bookmark this URL in your
browser to save the change query. This way it can be easily re-executed
later.

Several change queries can be also combined into a dashboard. A
dashboard is a screen in Gerrit that presents the results of several
change queries in different sections, each section having a descriptive
title.

A default dashboard is available under `My` > `Changes`. It has
sections to list outgoing reviews, incoming reviews and recently closed
changes.

Users can also define link:user-dashboards.html#custom-dashboards[
custom dashboards]. Dashboards can be bookmarked in a browser so that
they can be re-executed later.

It is also possible to link:#my-menu[customize the My menu] and add
menu entries for custom queries or dashboards to it.

Dashboards are very useful to define own views on changes, e.g. you can
have different dashboards for own contributions, for doing reviews or
for different sets of projects.

[NOTE]
You can use the link:user-search.html#limit[limit] and
link:user-search.html#age[age] query operators to limit the result set
in a dashboard section. Clicking on the section title executes the
change query without the `limit` and `age` operator so that you can
inspect the full result set.

Project owners can also define shared
link:user-dashboards.html#project-dashboards[dashboards on
project-level]. The project dashboards can be seen in the web UI under
`Projects` > `List` > <project-name> > `Dashboards`.

All dashboards and search pages allow an action to be applied to multiple
changes at once. Select the changes with the checkboxes on the left side and
choose the action from the action bar at the top of the change section.

[[submit]]
== Submit a Change

Submitting a change means that the code modifications of the current
patch set are applied to the target branch. Submit requires the
link:access-control.html#category_submit[Submit] access right and is
done on the change screen by clicking on the
link:user-review-ui.html#submit[Submit] button.

In order to be submittable changes must first be approved by
link:user-review-ui.html#vote[voting on the review labels]. By default
a change can only be submitted if it has a vote with the highest value
on each review label and no vote with the lowest value (veto vote).
Projects can configure link:intro-project-owner.html#labels[custom
labels] and link:intro-project-owner.html#submit-rules[custom submit
rules] to control when a change becomes submittable.

How the code modification is applied to the target branch when a change
is submitted is controlled by the
link:config-project-config.html#submit-type[submit type] which can be
link:intro-project-owner.html#submit-type[configured on project-level].

Submitting a change may fail with conflicts. In this case you need to
link:#rebase[rebase] the change locally, resolve the conflicts and
upload the commit with the conflict resolution as new patch set.

If a change cannot be merged due to path conflicts this is highlighted
on the change screen by a bold red `Cannot Merge` label.

[[rebase]]
== Rebase a Change

While a change is in review the HEAD of the target branch can evolve.
In this case the change can be rebased onto the new HEAD of the target
branch. When there are no conflicts the rebase can be done directly
from the link:user-review-ui.html#rebase[change screen], otherwise it
must be done locally.

.Rebase a Change locally
----
  // update the remote tracking branches
  $ git fetch

  // fetch and checkout the change
  // (checkout command copied from change screen)
  $ git fetch https://gerrithost/myProject refs/changes/74/67374/2 && git checkout FETCH_HEAD

  // do the rebase
  $ git rebase origin/master

  // resolve conflicts if needed and stage the conflict resolution
  ...
  $ git add <path-of-file-with-conflicts-resolved>

  // continue the rebase
  $ git rebase --continue

  // push the commit with the conflict resolution as new patch set
  $ git push origin HEAD:refs/for/master
----

Doing a manual rebase is only necessary when there are conflicts that
cannot be resolved by Gerrit. If manual conflict resolution is needed
also depends on the link:intro-project-owner.html#submit-type[submit
type] that is configured for the project.

Generally changes shouldn't be rebased without reason as it
increases the number of patch sets and creates noise with
notifications. However if a change is in review for a long time it may
make sense to rebase it from time to time, so that reviewers can see
the delta against the current HEAD of the target branch. It also shows
that there is still an interest in this change.

[NOTE]
Never rebase commits that are already part of a central branch.

[[move]]
== Move a Change

Changes can be link:rest-api-changes.html#move-change[moved] to a desired
destination branch in the same project. This is useful in cases where
development activity switches from one branch to another and there is a
need to move open changes on the inactive branch to the new active one.
Another useful case is to move changes from a newer branch back to an older
bugfix branch where an issue first appeared.

Users can move a change only if they have link:access-control.html#category_abandon[
abandon permission] on the change and link:access-control.html#category_push[
push permission] on the destination branch.

The move operation will not update the change's parent and users will have
to link:#rebase[rebase] the change.

[[abandon]]
[[restore]]
== Abandon/Restore a Change

Sometimes during code review a change is found to be bad and it should
be given up. In this case the change can be
link:user-review-ui.html#abandon[abandoned] so that it doesn't appear
in list of open changes anymore.

Abandoned changes can be link:user-review-ui.html#restore[restored] if
later they are needed again.

[[cherrypickof]]
== Cherry-Pick changes of a Change

When a change is created/updated using the 'cherry-pick' functionalty,
the original change and patchset details are recorded in the Change's
cherrypick field. This field cannot be set or updated by the user in
any way. It is set automatically after the cherry-pick operation completes
successfully.

[[topics]]
== Using Topics

Changes can be grouped by topics. This is useful because it allows you
to easily find related changes by using the
link:user-search.html#topic[topic search operator]. Also on the change
screen link:user-review-ui.html#same-topic[changes with the same topic]
are displayed so that you can easily navigate between them.

Often changes that together implement a feature or a user story are
group by a topic.

Assigning a topic to a change can be done in the
link:user-review-ui.html#project-branch-topic[change screen].

It is also possible to link:user-upload.html#topic[set a topic on
push], either by appending `%topic=...` to the ref name or through
the use of the command line flag `--push-option`, aliased to `-o`,
followed by `topic=...`.

Gerrit may be link:config-gerrit.html#change.submitWholeTopic[configured] to
submit all changes in a topic together with a single click, even when topics
span multiple projects.

.Set Topic on Push
----
  $ git push origin HEAD:refs/for/master%topic=multi-master

  // this is the same as:
  $ git push origin HEAD:refs/heads/master -o topic=multi-master
----

For more information about using topics, see the user guide:
link:cross-repository-changes.html[Submitting Changes Across Repositories by using Topics].

[[hashtags]]
== Using Hashtags

Hashtags are freeform strings associated with a change, like on social media
platforms. In Gerrit, you explicitly associate hashtags with changes using a
dedicated area of the UI; they are not parsed from commit messages or comments.

Similar to topics, hashtags can be used to group related changes together, and
to search using the link:user-search.html#hashtag[`hashtag:`] operator. Unlike
topics, a change can have multiple hashtags, and they are only used for
informational grouping; changes with the same hashtags are not necessarily
submitted together.

.Set Hashtag on Push
----
  $ git push origin HEAD:refs/for/master%t=stable-bugfix

  // this is the same as:
  $ git push origin HEAD:refs/heads/master -o t=stable-bugfix
----

[[wip]]
== Work-in-Progress Changes

Work-in-Progress (WIP) changes are visible to anyone, but do not notify or
require an action from a reviewer.

Specifically, when you mark a change as Work-in-Progress:

* Reviewers are not notified for most operations, such as adding or removing,
  posting comments, and so on. See the REST API documentation
  link:rest-api-changes.html#set-review-notifications[tables] for more
  information.
* The change does not show in reviewers' dashboards.

WIP changes are useful when:

* You have implemented only part of a change, but want to push your change
  to the server to run tests or perform other actions before requesting
  reviewer feedback.
* During a review, you realize you need to rework your change, and you
  want to stop notifying reviewers of the change until you finish your
  update.

To set the status of a change to Work-in-Progress, you can use either
the command line or the user interface. To use the command line, append
`%wip` to your push request.

----
  $ git push origin HEAD:refs/for/master%wip
----
Alternatively, click *WIP* from the *More* menu on the Change screen.
The Change screen updates with a yellow header, indicating that
the change is in a Work-in-Progress state.

To mark the change as ready for review, append `%ready` to your push
request.

----
  $ git push origin HEAD:refs/for/master%ready
----
There are two options for marking the change ready for review from the Change
screen:

1. Click *Start Review* (the primary action *Reply* is renamed when in WIP
state).
+
This will open the reply-modal and allow you to add reviewers and/or CC
before you start review.

2. Click button *Mark As Active*.
+
This will only change the state from WIP to ready, without opening the
reply-modal.

Change owners, project owners, site administrators and members of a group that
was granted link:access-control.html#category_toggle_work_in_progress_state[
Toggle Work In Progress state] permission can mark changes as `work-in-progress`
and `ready`.

[[private-changes]]
== Private Changes

Private changes are changes that are only visible to their owners, reviewers
and users with the link:access-control.html#category_view_private_changes[
View Private Changes] global capability. Private changes are useful in a number
of cases:

* You want a set of collaborators to review the change before formal review
  starts. By creating a Private change and adding only a selected few as
  reviewers you can control who can see the change and get a first opinion
  before opening up for all reviewers.

* You want to check what the change looks like before formal review starts.
  By marking the change private without reviewers, nobody can
  prematurely comment on your changes.

* You want to use Gerrit to sync data between different devices. By
  creating a private throwaway change without reviewers, you can push
  from one device, and fetch to another device.

Do *not* use private changes for making security fixes (see
link:#private-changes-pitfalls[pitfalls] below). How to make security
fixes is explained link:#security-fixes[below].

To create a private change, you push it with the `private` option.

.Push a private change
----
  $ git commit
  $ git push origin HEAD:refs/for/master%private
----

The change will remain private on subsequent pushes until you specify
the `remove-private` option. Alternatively, the web UI provides buttons
to mark a change private and non-private again.

When pushing a private change with a commit that is authored by another
user, the other user will not be automatically added as a reviewer and
must be explicitly added.

For CI systems that must verify private changes, a special permission
can be granted
(link:access-control.html#category_view_private_changes[View Private Changes]).
In that case, care should be taken to prevent the CI system from
exposing secret details.

[[private-changes-pitfalls]]
=== Pitfalls

If private changes are used, be aware of the following pitfalls:

* If a private change gets merged the corresponding commit gets visible
  for all users that can access the target branch and the private flag
  from the change is automatically removed. This makes private changes
  a bad choice for security fixes, as the security fix will be
  accessible as soon as the change was merged, but for security issues
  you want to keep an embargo until new releases have been made
  available.
* If you push a non-private change on top of a private change the
  commit of the private change gets implicitly visible through the
  parent relationship of the follow-up change.
* If you have a series of private changes and share one with reviewers,
  the reviewers can also see the commits of the predecessor private
  changes through the commit parent relationship.
* Users who would have permission to access the change except for its
  private status and knowledge of its commit ID (e.g. through CI logs
  or build artifacts containing build numbers) can fetch the code
  using the commit ID.

[[ignore]]
== Ignoring Or Marking Changes As 'Reviewed'

Changes can be ignored, which means they will not appear in the 'Incoming
Reviews' dashboard and any related email notifications will be suppressed.
This can be useful when you are added as a reviewer to a change on which
you do not actively participate in the review, but do not want to completely
remove yourself.

Alternatively, rather than completely ignoring the change, it can be marked
as 'Reviewed'. Marking a change as 'Reviewed' means it will not be highlighted
in the dashboard, until a new patch set is uploaded.

[[inline-edit]]
== Inline Edit

It is possible to link:user-inline-edit.html#editing-change[edit
changes inline] directly in the web UI. This is useful to make small
corrections immediately and publish them as a new patch set.

It is also possible to link:user-inline-edit.html#create-change[create
new changes inline].

[[roles]]
== Roles

Making and reviewing changes usually involves multiple users that
assume different roles:

- Author:
+
The person who wrote the code change. Recorded as author in the Git
commit.

- Committer:
+
The person who created the Git commit, e.g. the person that executed
the `git commit` command. Recorded as committer in the Git commit.

- Uploader:
+
The user that uploaded the commit as a patch set to Gerrit, e.g. the
user that executed the `git push` command. For commits that are created through
an action in the web UI the uploader is the user that triggered the action (e.g.
if a commit is created by clicking on the `REBASE` button, the user clicking on
the button becomes the uploader of the newly created commit).
+
The uploader of the first patch set is the change owner.
+
The uploader of the latest patch set, the user that uploaded the
current patch set, is relevant when
link:config-labels.html#label_ignoreSelfApproval[self approvals on labels are
ignored], as in this case approvals from the uploader of the latest patch set
are ignored.

- Change Owner:
+
The user that created the change, e.g. uploaded the first patch set.

- Reviewer:
+
A user that has reviewed the change or has been asked to review the change.

Often one user assumes several of these roles, but it's possible that each role
is assumed by a different user.

[[project-administration]]
== Project Administration

Every project has a link:intro-project-owner.html#project-owner[project
owner] that administrates the project. Project administration includes
the configuration of the project
link:intro-project-owner.html#access-rights[access rights], but project
owners have many more possibilities to customize the workflows for a
project which are described in the link:intro-project-owner.html[
project owner guide].

[[no-code-review]]
== Working without Code Review

Doing code reviews with Gerrit is optional and you can use Gerrit
without code review as a pure Git server.

.Push with bypassing Code Review
----
  $ git commit
  $ git push origin HEAD:master

  // this is the same as:
  $ git commit
  $ git push origin HEAD:refs/heads/master
----

[NOTE]
Bypassing code review must be enabled in the project access rights. The
project owner must allow it by assigning the
link:access-control.html#category_push_direct[Push] access right on the
target branch (`refs/heads/<branch-name>`).

[NOTE]
If you bypass code review you always need to merge/rebase manually if
the tip of the destination branch has moved. Please keep this in mind
if you choose to not work with code review because you think it's
easier to avoid the additional complexity of the review workflow; it
might actually not be easier.

[NOTE]
The project owner may enable link:user-upload.html#auto_merge[
auto-merge on push] to benefit from the automatic merge/rebase on
server side while pushing directly into the repository.

[[user-refs]]
== User Refs

User configuration data such as link:#preferences[preferences] is
stored in the `All-Users` project under a per-user ref.  The user's
ref is based on the user's account id which is an integer.  The user
refs are sharded by the last two digits (`+nn+`) in the refname,
leading to refs of the format `+refs/users/nn/accountid+`.

[[preferences]]
== Preferences

There are several options to control the rendering in the Gerrit web UI.
Users can configure their preferences under `Settings` > `Preferences`.
The user's preferences are stored in a `git config` style file named
`preferences.config` under the link:#user-refs[user's ref] in the
`All-Users` project.

The following preferences can be configured:

- [[page-size]]`Maximum Page Size`:
+
The maximum number of entries that are shown on one page, e.g. used
when paging through changes, projects, branches or groups.

- [[date-time-format]]`Date/Time Format`:
+
The format that should be used to render dates and timestamps.

- [[email-notifications]]`Email Notifications`:
+
This setting controls the email notifications.
+
** [[cc-me]]`Every comment`:
+
Email notifications are enabled and you get notified by email as CC
on comments that you write yourself.
+
** `Only comments left by others`
+
Email notifications are enabled for all activities excluding comments or
reviews authored by you.
+
** `Only when I am in the attention set`
+
Email notifications are only sent if the recipient is in the attention set.
+
** `None`:
+
Email notifications are disabled.

- [[email-format]]`Email Format`:
+
This setting controls the email format Gerrit sends. Note that this
setting has no effect if the administrator has disabled HTML emails
for the Gerrit instance.
+
** `Plaintext Only`:
+
Email notifications contain only plaintext content.
+
** `HTML and Plaintext`:
+
Email notifications contain both HTML and plaintext content.

- [[default-base-for-merges]]`Default Base For Merges`:
+
This setting controls which base should be pre-selected in the
`Diff Against` drop-down list when the change screen is opened for a
merge commit.
+
** `Auto Merge`:
+
Pre-selects `Auto Merge` in the `Diff Against` drop-down list when the
change screen is opened for a merge commit.
+
** `First Parent`:
+
Pre-selects `Parent 1` in the `Diff Against` drop-down list when the
change screen is opened for a merge commit.
+

- [[diff-view]]`Diff View`:
+
Whether the Side-by-Side diff view or the Unified diff view should be
shown when clicking on a file path in the change screen.

- [[show-site-header]]`Show Site Header / Footer`:
+
Whether the site header and footer should be shown.

- [[relative-dates]]`Show Relative Dates In Changes Table`:
+
Whether timestamps in change lists and dashboards should be shown as
relative timestamps, e.g. '12 days ago' instead of absolute timestamps
such as 'Apr 15'.

- [[change-size-bars]]`Show Change Sizes As Colored Bars`:
+
Whether change sizes should be visualized as colored bars. If disabled
the numbers of added and deleted lines are shown as text, e.g.
'+297, -63'.

- [[show-change-number]]`Show Change Number In Changes Table`:
+
Whether in change lists and dashboards an `ID` column with the numeric
change IDs should be shown.

- [[mute-common-path-prefixes]]`Mute Common Path Prefixes In File List`:
+
Whether common path prefixes in the file list on the change screen
should be link:user-review-ui.html#repeating-path-segments[grayed out].

- [[inline-signed-off]]`Insert Signed-off-by Footer For Inline Edit Changes`:
+
Whether a `Signed-off-by` footer should be automatically inserted into
changes that are created from the web UI (e.g. by the `Create Change`
and `Edit Config` buttons on the project screen, and the `Follow-Up`
button on the change screen).

- [[publish-comments-on-push]]`Publish comments on push`:
+
Whether to publish any outstanding draft comments by default when pushing
updates to open changes. This preference just sets the default; the behavior can
still be overridden using a link:user-upload.html#publish-comments[push option].

- [[use-flash]]`Use Flash Clipboard Widget`:
+
Whether the Flash clipboard widget should be used. If enabled and the Flash
plugin is available, Gerrit offers a copy-to-clipboard icon next to IDs and
commands that need to be copied frequently, such as the Change-Ids, commit IDs
and download commands. Note that this option is only shown if the Flash plugin
is available and the JavaScript Clipboard API is unavailable.

- [[work-in-progress-by-default]]`Set new changes work-in-progress`:
+
Whether new changes are uploaded as work-in-progress per default. This
preference just sets the default; the behavior can still be overridden using a
link:user-upload.html#wip[push option].

[[my-menu]]
In addition it is possible to customize the menu entries of the `My`
menu. This can be used to make the navigation to frequently used
screens, e.g. configured link:#dashboards[dashboards], quick.

[[reply-by-email]]
== Reply by Email

Gerrit sends out email notifications to users and supports parsing back replies
on some of them (when link:config-gerrit.html#receiveemail[configured]).

Gerrit supports replies on these notification emails:

* Notifications about new comments
* Notifications about new labels that were applied or removed

While Gerrit supports a wide range of email clients, the following ones have
been tested and are known to work:

* Gmail
* Gmail Mobile

Gerrit supports parsing back all comment types that can be applied to a change
via the WebUI:

* Change messages
* Inline comments
* File comments

Please note that comments can only be sent in reply to a comment in the original
notification email, while the change message is independent of those.

Gerrit supports parsing a user's reply from both HTML and plaintext. Please note
that some email clients extract the text from the HTML email they have received
and send this back as a quoted reply if you have set the client to plaintext
mode. In this case, Gerrit only supports parsing a change message. To work
around this issue, consider setting a <<email-format,User Preference>> to
receive only plaintext emails.

Example notification:
----
Some User has posted comments on this change.
(https://gerrit-review.googlesource.com/123123 )

Change subject: My new change
......................................................................


Patch Set 3:

Just a couple of smaller things I found.

https://gerrit-review.googlesource.com/#/c/123123/3/MyFile.java
File
MyFile.java:

https://gerrit-review.googlesource.com/#/c/123123/3/MyFile@420
PS3, Line 420:     someMethodCall(param);
Seems to be failing the tests.


--
To view, visit https://gerrit-review.googlesource.com/123123
To unsubscribe, visit https://gerrit-review.googlesource.com/settings

(Footers omitted for brevity, must be included in all emails)
----

Example response from the user:
----
Thanks, I'll fix it.
> Some User has posted comments on this change.
> (https://gerrit-review.googlesource.com/123123 )
>
> Change subject: My new change
> ......................................................................
>
>
> Patch Set 3:
>
> Just a couple of smaller things I found.
>
> https://gerrit-review.googlesource.com/#/c/123123/3/MyFile.java
> File
> MyFile.java:
Rename this file to File.java
>
> https://gerrit-review.googlesource.com/#/c/123123/3/MyFile@420
> PS3, Line 420:     someMethodCall(param);
> Seems to be failing the tests.
>
Yeah, I see why, let me try again.
>
> --
> To view, visit https://gerrit-review.googlesource.com/123123
> To unsubscribe, visit https://gerrit-review.googlesource.com/settings
>
> (Footers omitted for brevity, must be included in all emails)
----

In this case, Gerrit will persist a change message ("Thanks, I'll fix it."),
a file comment ("Rename this file to File.java") as well as a reply to an
inline comment ("Yeah, I see why, let me try again.").

[[security-fixes]]
-- Security Fixes

If a security vulnerability is discovered you normally want to have an
embargo about it until fixed releases have been made available. This
means you want to develop and review security fixes in private.

If your repository is public or grants broad read access it is
recommended to fix security issues in a copy of your repository which
has very restricted read permissions (e.g. `myproject-security-fixes`).
You can then implement, review and submit the security fix in this
repository, make and publish a new release and only then integrate the
security fix back into the normal (public) repository.

Alternatively you can do the security fix in your normal repository in
a branch with restricted read permissions. We don't recommend this
because there is a risk of configuring the access rights wrongly and
unintentionally granting read access to the wrong people.

Using private changes for security fixes is *not* recommended due to
the link:#private-changes-pitfalls[pitfalls] discussed above.
Especially you don't want the fix to become visible after submit and
before you had a chance to make and publish a new release.

GERRIT
------
Part of link:index.html[Gerrit Code Review]

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