- Instead of overriding `create` and `update` in `MergeRequests::BaseService`
- Get all merge request service specs passing

- Don't use `TableReferences` - using `.arel_table` is shorter!
- Move some database-related code to `Gitlab::Database`
- Remove the `MergeRequest#issues_closed` and
  `Issue#closed_by_merge_requests`  associations. They were either
  shadowing or were too similar to existing methods. They are not being
  used anywhere, so it's better to remove them to reduce confusion.
- Use Rails 3-style validations
- Index for `MergeRequest::Metrics#first_deployed_to_production_at`
- Only include `CycleAnalyticsHelpers::TestGeneration` for specs that
  need it.
- Other minor refactorings.

Helper methods are meant for views

And `scss_lint`

- Move things common to `Issue` and `MergeRequest` into `Issuable`
- Move more database-specific functions into `Gitlab::Database`
- Indentation changes and other minor refactorings.

Incorrect syntax.

- Public projects - anyone can access
- Private projects - any member (guest level and above) can access

1. Change multiple updates to a single `update_all`

2. Use cascading deletes

3. Extract an average function for the database median.

4. Move database median to `lib/gitlab/database`

5. Use `delete_all` instead of `destroy_all`

6. Minor refactoring

1. Dispatch between the two strategies automatically based on the
   current database type.

2. The MySQL version needs to run multiple statements, so the
   `cycle_analytics` model is modified to support this.

1. Add indexes to `CreateMergeRequestsClosingIssues` columns.
2. Remove an extraneous `check_if_open` check that is redundant now.

It would've been better to rebase this in, but that's not possible
because more people are working on this branch.

A number of failures were introduced due to performance
improvements (like pre-calculating metrics).

1. Look for merge requests (and issues that they close) that have been
   deployed to production in the last X days (where X is given by the
   `from` parameter).

2. Cycle analytics queries only operate on this fitered set of merge
   requests and issues.

Remove trailing spaces from messages in Gitlab::Regex

See merge request !6426

Fix broken spec due to last_activity_at updates being throttled

In https://gitlab.com/gitlab-org/gitlab-ce/builds/4218398, the build failed because the last_activity_at column was only being updated once per hour. We
can fix this spec by stubbing out the throttling and adjusting the spec to test the right event timestamp.

See merge request !6424

Fix download artifacts button link

## What does this MR do?

Fix download artifacts button link.

## Does this MR meet the acceptance criteria?

- [ ] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- Tests
  - [x] Added for this feature/bug

## What are the relevant issue numbers?

Closes #22294

See merge request !6407

* upstream/master: (80 commits)
  Contributing via GH no longer encouraged.
  Update README.md to really fix icon
  Update README.md to fix icon
  Allow to set request_access_enabled for groups and projects using API
  Restrict last_activity_at updates to one per hour
  Solve code review comments
  Properly support Gitlab::Auth::Result
  Revert all changes introduced by https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6043
  Move Gitlab::Auth.Result to separate file
  Added CHANGELOG
  Fix spec failures
  Support pushing via SSH
  Fix specs failures
  Don't leak build tokens in build logs
  Fix permissions for creating container images
  Fix old CHANGELOG entries
  Add linting for duplicate CHANGELOG versions (!6039)
  Ensure validation messages are shown within the milestone form
  Fix validation regexs (+1 squashed commit) Squashed commits: [f9a9315] Use : to test invalid environment name
  Fix scope of the CI config key nodes in jobs entry
  ...

In https://gitlab.com/gitlab-org/gitlab-ce/builds/4218398, the build failed
because the last_activity_at column was only being updated once per hour. We
can fix this spec by stubbing out the throttling and adjusting the spec to
test the right event timestamp.

Use gitlab-workhorse 0.8.2

Fixes rejected API git archive extensions; improves Sentry errors.

https://gitlab.com/gitlab-org/gitlab-workhorse/blob/master/CHANGELOG

See merge request !6388

Move LDAP user attributes to a method

## What does this MR do?

This is a change that supports an EE fix. This small change needs to be made in CE to prevent future merge conflicts. 
See https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/736 for the EE changes.

See merge request !6377

Strip comments before sending keys to gitlab-shell

## Why was this MR needed?

https://gitlab.com/gitlab-org/gitlab-ce/issues/22167 encoding issues in comment text.

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/issues/22167

See merge request !6381

Ensure invitees are not returned in Members API

## What are the relevant issue numbers?

Closes #22065

See merge request !6370