CE to EE following update of `db/schema.rb` with `activerecord_sane_schema_dumper`

Resolved conflicts:

```
UU app/controllers/projects/merge_requests_controller.rb
UU app/helpers/merge_requests_helper.rb
UU app/views/projects/merge_requests/widget/_open.html.haml
UU db/schema.rb
UU doc/README.md
UU spec/lib/extracts_path_spec.rb
UU spec/services/merge_requests/refresh_service_spec.rb
```

See merge request !800

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

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

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

Fix Git access panel for Wikis when Kerberos authentication is enabled

When Kerberos authentication is enabled, the `Git Access` panel for project's Wiki return a 500 Error. Details in #1109   
The MR provides the missing code to generate the Kerberos URL for Wiki projects.  
Closes #1109

See merge request !795

Added documentation chapter for Git attributes

See https://gitlab.com/gitlab-org/gitlab_git/issues/28 for more information.

See merge request !6826

Use activerecord_sane_schema_dumper

## What does this MR do?

EE side of https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6827.

> `ActiveRecord::SaneSchemaDumper` modifies the behavior of Rails’ `ActiveRecord::SchemaDumper` so that the generated `db/schema.rb` file doesn’t contain any useless/harmful whitespace column alignment.

## Why was this MR needed?

To reduce potential conflicts in `db/schema.rb` (see https://gitlab.com/gitlab-org/gitlab-ee/issues/715).

See merge request !799

Use activerecord_sane_schema_dumper

## What does this MR do?

> `ActiveRecord::SaneSchemaDumper` modifies the behavior of Rails’ `ActiveRecord::SchemaDumper` so that the generated `db/schema.rb` file doesn’t contain any useless/harmful whitespace column alignment.

## Why was this MR needed?

To reduce potential conflicts in `db/schema.rb` (see https://gitlab.com/gitlab-org/gitlab-ee/issues/715).

See merge request !6827

As discussed in https://gitlab.com/gitlab-org/gitlab_git/issues/28 we'll
need to clearly document the need for .gitattributes files being encoded
using UTF-8.

[ci skip]

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

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

API: New /users/:id/events endpoint

## What does this MR do?

If add a new `/users/:id/events` endpoint to retrieve a user's contribution events. The events returned are filtered so that only the events for projects that the current user can see are returned (similarly to what we do at the controller level).

## Why was this MR needed?

Because it's a nice feature to calculate leaderboards, for instance for #17815.

## What are the relevant issue numbers?

Closes #20866.

See merge request !6771

Add disabled delete button to protected branches

## What does this MR do?
Add's a disabled CSS style for the delete button on protected branches instead of hiding the button

## What are the relevant issue numbers?
Closes #22358

See merge request !6439

Speed up specs for GET /projects/:id/events

## What does this MR do?

Just groups some expectations into a single `it` block. Reduce this particular tests block time by half.

See merge request !6778

Removes inconsistency regarding tagging immediately as merged once you create a …

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- [x] API support added
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] 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)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #20708

See merge request !6408

Set default_label attribute on weight issue filter.

The label for the "Weight" filter in the issues list is darker than the other filters. 

This MR sets the `default_label` attribute to 'Weight', so that the styles for default labels are applied to "Weight". This is the convention for other filter dropdowns. 

I'm guessing it regressed here 8961364c. The default_label was not set when the weight filter was originally transitioned to the new dropdown (https://gitlab.com/gitlab-org/gitlab-ee/commit/b0639b1fdafd0cf48f1fcdaa8047f7414010e643). I'm guessing some styles were unintentionally cascading to give this the correct look, and were changed.

Closes https://gitlab.com/gitlab-org/gitlab-ee/issues/1094

See merge request !794

Added 'Download' button to snippet view

## What does this MR do?

Adds a `Download` button above a snippet.

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

## Why was this MR needed?

Requested in #22811 

## Screenshots (if relevant)

![image](/uploads/59b67aa02cc601c08a18fd60c37797ed/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?

Closes #22811

See merge request !6720

Add CHANGELOG entry for 8.12.6



See merge request !6816

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

Fix JS bug with select2 because of missing `data-field` attribute in select box.

Fix JS bug with select2 because of missing `data-field` attribute in select box.

Fixes #23193

See merge request !6812

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

API: Share projects only with groups current_user can access

Aims to address the issues here: https://gitlab.com/gitlab-org/gitlab-ce/issues/23004

* Projects can be shared with non-existent groups
* Projects can be shared with groups that the current user does not have access to read

Concerns:

The new implementation of the API endpoint allows projects to be shared with a larger range of groups than can be done via the web UI.

The form for sharing a project with a group uses the following API endpoint to index the available groups: https://gitlab.com/gitlab-org/gitlab-ce/blob/494269fc92f61098ee6bd635a0426129ce2c5456/lib/api/groups.rb#L17. The groups indexed in the web form will only be those groups that the user is currently a member of.

The new implementation allows projects to be shared with any group that the authenticated user has access to view. This widens the range of groups to those that are public and internal.

See merge request !2005
Signed-off-by: Rémy Coutable <remy@rymai.me>

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

allow multiple labels commands

### What does this MR do?
This MR should add multiple command support  for all  label related commands.

### What are the relevant issue numbers?
Closes #22965

See merge request !6780

Respond with 404 Not Found for non-existent tags

## What does this MR do?

Handles the case when a non-existent tag is being viewed, and responds with 404 Not Found instead of 500 Internal Server Error.

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

The small changes should be clear from a simple diff.

## Why was this MR needed?

To resolve the issue #22211.

## Screenshots (if relevant)

## 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
  - [x] All builds are passing
- [x] 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)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?


Closes #22211

See merge request !6699

Ability to bulk assign issues to author of merge request

## What does this MR do?
Provides a link to auto-assign issues to the author of a merge request, when they are mentioned as being closed by the MR.

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


## Why was this MR needed?
To help avoid working on a MR without having assigned related issues to self

## What are the relevant issue numbers?
Fixes #18876 

## Screenshots (if relevant)
![ScreenShot-P216](/uploads/1af5e71a0a0ff0a60c5d7b54c0e09d9c/ScreenShot-P216.png)

## Tasks
- [x] Refactor or move away from using `BulkUpdateService`
- [x] ~~Consider alternate link message when only a subset of issues will be assigned~~
- [x] Minimize repeated calls to expensive `closes_issues` method
- [x] Move away from using inflector for pluralization and fix flash message
- [x] Change auth `before_action` and fallback to error flash message
- [x] Shouldn't overwrite current assignee if one exists

## Does this MR meet the acceptance criteria?

- [x] [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- [x] ~~[Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~
- [x] ~~API support added~~
- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [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)
- [x] [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

See merge request !5725

Make guests unable to view MRs

## What does this MR do?

Make guests unable to view MRs. This also fixes a bug when a non-member user could get notification if mentioned (in private project, it's OK for public project).

Now if you are a guest and you will be mentioned in one of the MRs you won't get a notification. 

## What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/1410

See merge request !6673

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

Build instead create in label_link model spec

## What does this MR do?
This MR improves spec for label link model.

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

## Why was this MR needed?
Because for check validations, we can use build instead create a record in the database. 

## Screenshots (if relevant)
No

## Does this MR meet the acceptance criteria?

- n/a [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- n/a [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- n/a API support added
- Tests
  - n/a Added for this feature/bug
  - [x] All builds are passing
- [x] 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 it does - rebase it please)
- n/a [Squashed related commits together](https://git-scm.com/book/en/Git-Tools-Rewriting-History#Squashing-Commits)

## What are the relevant issue numbers?

See merge request !6792

Remove empty describe block on key spec model

## What does this MR do?
Removes unnecessary describe in test

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

## Why was this MR needed?
It describe block not needed.

## Screenshots (if relevant)
No

## Does this MR meet the acceptance criteria?

- n/a [CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added
- n/a [Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)
- n/a API support added
- Tests
  - n/a Added for this feature/bug
  - [x] All builds are passing
- [x] 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 it does - 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?
No

See merge request !6793

Merge CacheMarkdownField to EE

This branch merges http://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6095 into gitlab-ee, fixing merge conflicts.

It also merges a lot of unrelated commits in, as the MR was ahead of EE's current master.

See merge request !789

Move some CHANGELOG entries to the 8.13.0 part

Spotted while reviewing https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/789/diffs#diff-1

[ci skip]

See merge request !6809