API: Return 404 when trying to fork to unaccessible namespace

Closes #22417

See merge request !6452

Fix pipeline error when trying to read empty merge request diff

When a user pushed something which resulted an empty merge request diff, `st_commits` would be `nil`. Therefore we also need to check if there exists `st_commits`.

We could tell this from:

``` ruby
def commits
  @commits ||= load_commits(st_commits || [])
end
```

and

``` ruby
def save_commits
  new_attributes = {}

  commits = compare.commits

  if commits.present?
    commits = Commit.decorate(commits, merge_request.source_project).reverse
    new_attributes[:st_commits] = dump_commits(commits)
  end

  update_columns_serialized(new_attributes)
end
```

Closes #22438

See merge request !6470

Fixups for Frontend for Merge Request Diff

## What does this MR do?

Makes a few revisions to https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6343, as per feedback from @DouweM. Specifically, it removes a duplicate in the changelog, removes colons in dropdowns, uses icon helper, and fixes the 'Show original' link path.

## Why was this MR needed?

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6343 was already merged and this is a needed patch. 

## What are the relevant issue numbers?

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6343

See merge request !6448

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

Update merge request versions documentation with new screenshots

For #13570 based on https://gitlab.com/gitlab-org/gitlab-ce/issues/21427

See merge request !6454

Hotfix the issuable counters when filtering by multiple labels

This is an ugly fix, but it make the counters work when multiple labels are selected so I think we should include it in 8.12, and try to find a proper fix afterward.

Closes #22421

See merge request !6455

Update db/schema.rb per most recent migrations



See merge request !6446

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6470#note_15856755

Bump gitlab-shell upgrade version to 3.6.0 for 8.12

[ci skip]

Closes #22442

See merge request !6469

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

(Also removes duplicate changelog entry.)

Closes #22438

[ci skip]

Fix typos in cycle analytics docs



See merge request !6467

[ci skip]

Change location and refactor issue closing pattern documentation

## Moving docs to a new location?

See the guidelines: http://docs.gitlab.com/ce/development/doc_styleguide.html#changing-document-location

- [x] Make sure the old link is not removed and has its contents replaced with a link to the new location.
- [x] Make sure internal links pointing to the document in question are not broken.
- [x] Search and replace any links referring to old docs in GitLab Rails app, specifically under the `app/views/` directory.
- [x] If working on CE, submit an MR to EE with the changes as well.

See merge request !6466

Split into user and administrator docs:

- administration/issue_closing_pattern.md
- user/project/issues/automatic_issue_closing.md

[ci skip]

This reverts merge request !6429

Reorganize sections in Admin area settings

## What does this MR do?

Some settings were under the "wrong" category. This is an attempt to provide proper categories and move relevant settings there.

## What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/20126


See merge request !5449

It seems this wasn't updated properly when migrations were added in a
previous commit.

Add default values for ProjectFeature

See merge request !6447

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

Revert "Merge branch 'rs-update-rubocop-rspec' into 'master'"

Reverts https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6357
due to rubocop-rspec dropping support for Ruby 2.1.

See https://github.com/backus/rubocop-rspec/pull/131

See merge request !6444

And Snippets get awards

## What does this MR do?

Makes snippets more awesome, by making them awardables

## Why was this MR needed?

Because Snippets were left behind.

## What are the relevant issue numbers?

Closes #17878

See merge request !4456

Changed `Commit` to `Build` header on builds table

## What does this MR do?

As [discussed here](https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6322#note_15511777) the pipeline table `Commit` headers should be `Pipeline`. This also should apply to build table headers.

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

/cc @tauriedavis 

## Why was this MR needed?

UI consistency

## Screenshots (if relevant)

![Screen_Shot_2016-09-18_at_16.39.16](/uploads/61e64fb3152ac3ec81bec35c5ba0e312/Screen_Shot_2016-09-18_at_16.39.16.png)

## Does this MR meet the acceptance criteria?

- [ ] [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)
- [ ] 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?

See merge request !6402

Simplify ProjectTeam#fetch_members to satisfy flog

## What does this MR do?

- Add specs for ProjectTeam#fetch_members
- Simplify ProjectTeam#fetch_members to satisfy flog

## What are the relevant issue numbers?

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/22200

See merge request !6431

Fix Import/Export security specs

Related https://dev.gitlab.org/gitlab/gitlabhq/merge_requests/1987#note_83855

See merge request !1997

Shrink profile info

## What does this MR do?
Updates design of profile page to match comps

## Screenshots (if relevant)
![Screen_Shot_2016-09-16_at_11.34.21_AM](/uploads/5c2f510e6cc64bf466309db8ec02b9e0/Screen_Shot_2016-09-16_at_11.34.21_AM.png)
![Screen_Shot_2016-09-16_at_11.35.20_AM](/uploads/ebd3471965340fce5a897dcfc1a5385c/Screen_Shot_2016-09-16_at_11.35.20_AM.png)

## Does this MR meet the acceptance criteria?

- [ ] [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)
- [ ] 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 https://gitlab.com/gitlab-org/gitlab-ce/issues/18071

See merge request !6394

Show all pipelines from all merge_request_diffs

This way we could also show pipelines from commits which
were discarded due to a force push.

Closes #21889

See merge request !6414

Closes gitlab-org/gitlab-ce#22330

Limit number of shown environments

## What does this MR do?

This MR limits in context of Merge Request a list of shown environments. Previously we would show all environments containing the SHA of the head commit of Merge Request. However, with introducing of dynamically created environments this lead to a cases that we would show multiple review apps, for different branches, because these branches would contain a new questioned commit.

This MR changes what environments we test against presence of the commit, to:
1. We look for environments with deployments to source_branch of source_project: used for deployments to per-branch environments,
2. We look for environments with deployments to target_branch of target_project: used for deployments to staging / production environments,
3. We look for environments with deployments for tags on target_project: used for staging / production environments.

## Why was this MR needed?

To improve a list of returned environments when we introduced ability to create dynamic environments for review apps:
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6323

See merge request !6438