This commit introduces a Sidekiq worker that precalculates the list of
trending projects on a daily basis. The resulting set is stored in a
database table that is then queried by Project.trending.

This setup means that Unicorn workers no longer _may_ have to calculate
the list of trending projects. Furthermore it supports filtering without
any complex caching mechanisms.

The data in the "trending_projects" table is inserted in the same order
as the project ranking. This means that getting the projects in the
correct order is simply a matter of:

    SELECT projects.*
    FROM projects
    INNER JOIN trending_projects ON trending_projects.project_id = projects.id
    ORDER BY trending_projects.id ASC;

Such a query will only take a few milliseconds at most (as measured on
GitLab.com), opposed to a few seconds for the query used for calculating
the project ranks.

The migration in this commit does not require downtime and takes care of
populating an initial list of trending projects.

reword title for issues_controller#show and issues_controller#edit

Closes #21712

See merge request !6503

Prevent conflict b/w search field and its dropdown

What does this MR do?

Stops the global search form's default "action" from fighting with
dropdown items when using the keyboard to navigate the dropdown.
`e.preventDefault()` is now called on the enter key when a dropdown item
is already selected.

Closes #22872

See merge request !6643

Stop the global search form's default "action" from fighting with
dropdown items when using the keyboard to navigate the dropdown.
`e.preventDefault()` is now called on the enter key when a dropdown item
is already selected.
Signed-off-by: Rémy Coutable <remy@rymai.me>

Fix missing constraints causing route failures when usernames with periods are used

Closes #23131

See merge request !6758

Closes #23131

Use Hash rocket syntax to maintain Ruby 2.1 compatibility in spec

Builds in Ruby 2.1 specs were failing in master: https://gitlab.com/gitlab-org/gitlab-ce/builds/4883142

See merge request !6756

Truncate long labels with ellipsis in labels page

## What does this MR do?
Fixes #22953, where long labels overlaps into the description field in the labels page. Truncates long labels with ellipsis. Labels that fit are unaffected.

## Are there points in the code the reviewer needs to double check?
No

## Why was this MR needed?
Fixes #22953.

## Screenshots (if relevant)
Existing behavior:
![image](/uploads/4d85730fe9d039d91036d09bf892d9f2/image.png)

With the change:
![desktop](/uploads/6866389cc3a1e2af5c2def59536a2a7c/desktop.png)
![mobile](/uploads/3d1fbb4a3470abefdd3670f7a794d2a8/mobile.png)

## Does this MR meet the acceptance criteria?
- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [ ] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
Closes #22953

See merge request !6725

Improve the contribution and MR review guide

## What does this MR do?

This merge request improves the contributing and MR review guides following @stanhu's reply on https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6096#note_16537211.

## Why was this MR needed?

To clearly state that MR reviews can take multiple iterations but that as reviewers we should do our best to minimize the number of iterations and take over any MR that is set as "Merge when build succeeds" at some point.

See merge request !6739

ExpireBuildArtifactsWorker query builds table without ordering enqueuing one job…

See merge request !6732

Fix Ubuntu 16.04.1 update process using systemctl daemon-reload

See merge request !6666

Resolve "Retouch environments list and deployments list"

## What does this MR do?
#### Environments List
- Fixes deployment ID
- Removes bold styling from deployment ID
- Changes Las Deployment Column to have '#ID by user'
- Adds build column with link to the build
- Adds external url to where the environment is hosted

#### Environment Details
- Add link to the build column and changes content to show "build (#id) by user"
- Adds external link to the review app

Adds tests

## Screenshots (if relevant)
#### Environments List
![env_list](/uploads/6cfd737bb0d2f2853a610479877de5a3/env_list.png)
#### Environments Details
![env_details](/uploads/70ec59d7d7de5c1ef57132c2ec9c1b8f/env_details.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [x] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [ ] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?
Closes #22774

See merge request !6691

Make Member#add_user set access_level for requesters

## What does this MR do?

This is a backport of https://gitlab.com/gitlab-org/gitlab-ee/commit/c902d8d48409a4d46f7669fc5fc85b9ba86e71d6 from gitlab-org/gitlab-ee!744.

## Why was this MR needed?

This change is only used in EE right now, but there's no reason why it wouldn't be part of CE.

See merge request !6649

Optimize the `award_user_list` helper spec

According to
https://gitlab.com/gitlab-org/gitlab-ce/issues/23034#note_16586657, each
test for this helper generated 1,833 queries.

Now we only generate stubbed records, and only as many as we need for
each test.

This also corrects a slight logic bug in the helper itself. When the
number of awards was greater than the limit (9 by default), _and_ the
current user was one of them, we actually included 10 names, including
"You", plus the remaining count. Now we return the correct number
regardless.

See merge request !6722

Added missing content and improved layout

## What does this MR do?

Restores lost content that was removed from the University landing page.
Adds many videos, presentations and blog articles that were never in University.
Improves the layout of the content.

## Are there points in the code the reviewer needs to double check?

I'd like feedback on the content organisation, specifically if certain sub sections should be moved e.g. from Beginner to Intermediate. Keep in mind how this change will affect the relative difficulty of the other content.

## Why was this MR needed?

The layout looked unprofessional and was missing crucial content.

## What are the relevant issue numbers?

Closes #23051

See merge request !6741

According to
https://gitlab.com/gitlab-org/gitlab-ce/issues/23034#note_16586657, each
test for this helper generated 1,833 queries.

Now we only generate stubbed records, and only as many as we need for
each test.

This also corrects a slight logic bug in the helper itself. When the
number of awards was greater than the limit (9 by default), _and_ the
current user was one of them, we actually included 10 names, including
"You", plus the remaining count. Now we return the correct number
regardless.

Signed-off-by: Rémy Coutable <remy@rymai.me>

ExpireBuildArtifactsWorker query builds table without ordering enqueuing one job per build to cleanup

We use Sidekiq::Client.push_bulk to avoid Redis round trips

Signed-off-by: Rémy Coutable <remy@rymai.me>

Update user whitelist reject message

## What does this MR do?

Makes email whitelist rejection message more generic. Stops printing all `allowed_domains`

## Why was this MR needed?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/23090

See merge request !6731

Fix Event#reset_project_activity updates

See merge request !6729

Memoize Github::Shell's secret token

## What does this MR do?

`API::Helpers#secret_token` was reading the secret file on every invocation. This MR reads the file in the `gitlab_shell_secret_token.rb` initializer and saves it as a class variable at `Gitlab::Shell.secret_token`

## Are there points in the code the reviewer needs to double check?

 - I'm not sure if the use of `cattr_accessor` is the best approach, or if should be moved into the `class << self` block?
 - Should `API::Helpers#secret_token` be removed in favor of using `Gitlab::Shell.secret_token`?

## Why was this MR needed?

Performance optimization.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/22510

See merge request !6599

Add visible projects API

## What does this MR do?

Add a new `/projects/visible` API endpoint. Originally created by @ben.boeckel in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5970.

## Are there points in the code the reviewer needs to double check?

Does the API make sense?

## Why was this MR needed?

The `/projects` endpoint only returned projects the user was explicitly a member of.

Closes #19361, #3119.

See merge request !6681

Resolve "NameError: undefined local variable or method `request' for #<Grape::Middleware::Error:0x007fc990..."

## What does this MR do?

Switches from `request` to `env` in an API helper method as the helpers are included in contexts lacking `request`.

## Are there points in the code the reviewer needs to double check?

I couldn't build a reproducer for this.

Closes #22820

See merge request !6615

Cache rendered Markdown fields in the database

## What does this MR do?

Introduces cache fields for Markdown-containing fields in the database, and populates them.

## Why was this MR needed?

Rendering Markdown into HTML is performance-intensive. A Redis cache already exists, but this approach is expected to be more performant and reduce unnecessary cache invalidations.

## What are the relevant issue numbers?

Closes #18337

See merge request !6095

Add notice about HTTPS cloning for CI

## What does this MR do?
Adds a notice about potential problem with GitLab CI unable to clone sources: https://gitlab.com/gitlab-org/gitlab-ce/issues/22484#note_16612187

## Issues
Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/22484

See merge request !6719

!6678 removed the lease from Event#reset_project_activity, but it wasn't
actually updating the project's last_activity_at timestamp properly.
The WHERE clause would always return no matching projects. The spec
passed occasionally because the created_at timestamp was automatically
set to last_activity_at.

  + Don't expose all whitelisted domains

Call ensure_secret_token! in secret token test's before block since it would be called in an initializer.

Add tooltip to project fork count

## What does this MR do?

Adds a tooltip reading `Forks` when a user hovers over the count of project forks.

## Are there points in the code the reviewer needs to double check?

## Why was this MR needed?

Requested in #23066 

## Screenshots (if relevant)

![image](/uploads/023af8dc4df68549705f6a328cf8031c/image.png)

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [ ] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [ ] API support added
- Tests
  - [ ] Added for this feature/bug
  - [ ] All builds are passing
- [ ] Conform by the [merge request performance guides](http://docs.gitlab.com/ce/development/merge_request_performance_guidelines.html)
- [ ] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

#23066

See merge request !6718

This commit alters views for the following models to use the markdown cache if
present:

* AbuseReport
* Appearance
* ApplicationSetting
* BroadcastMessage
* Group
* Issue
* Label
* MergeRequest
* Milestone
* Project

At the same time, calls to `escape_once` have been moved into the `single_line`
Banzai pipeline, so they can't be missed out by accident and the work is done
at save, rather than render, time.

Truncato is introduced as a dependency to intelligently shorten the rendered
HTML to 200 characters; the previous approach could have resulted in invalid
HTML being rendered.