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

same time and writes tests accordingly

changes schema.db

removes duplicate field inside CHANGELOG

fix db/schema

* This method previously iterated over all services in a project.  Now it
will directly query the ExternalWikiService for the project and filter
by active state.
* The presence of an external wiki is also cached
* When an external wiki is added or removed, the cached value is updated

Refactor and rename `restricted_signup_domains` to `domain_whitelist` to better conform to its behavior and newly introduced behavior.

- This was introduced (at some point) while rebasing `master` against
  the "developers can merge" feature branch.

- https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/5310#note_13139705

This reverts commit 530f5158.

See !4892.
Signed-off-by: NRémy Coutable <remy@rymai.me>

This reverts commit c3935699.

This reverts commit 9ca633eb, reversing
changes made to fb229bbf.

1. When a merge request is being merged, save the merge commit SHA in
   the `in_progress_merge_commit_sha` database column.

2. The `pre-receive` hook looks for any locked (in progress) merge
   request with `in_progress_merge_commit_sha` matching the `newrev` it
   is passed.

3. If it finds a matching MR, the merge is legitimate.

4. Update `git_access_spec` to test the behaviour we added here. Also
   refactored this spec a bit to make it easier to add more contexts / conditions.

- Cherry-picked from `mvestergaard:branch-protection-dev-merge`
- https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4220

As requested by the issue #14508 this adds an option in the application
settings to set newly registered users by default as external. The
default setting is set to false to stay backward compatible.

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

Feedback:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4964#note_12741046

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4093#note_12571602
and
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4093#note_12571670

This reverts commit 13e37a3e.

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

This is done to make belongs_to with required to properly validate association.
Otherwise `ActiveRecord::StatementInvalid` is raised.