Here was the problem:

1. When determining whether a given blob is viewable text, gitlab_git reads the first 1024 bytes and checks with Linguist whether it is a text or binary file.
2. If the blob is text, GitLab will attempt to display it.
3. However, if the text has binary characters after the first 1024 bytes, then GitLab will attempt to load the entire contents, but the encoding will be ASCII-8BIT since there are binary characters.
4. The Error 500 results when GitLab attempts to display a mix UTF-8 and ASCII-8BIT.

To fix this, we load as much data as we are willing to display so that the detection will work properly. Requires
an update to gitlab_git: gitlab-org/gitlab_git!86

Closes #13826

Only create the backup directory if it is local

Closes #12710

See merge request !4551

Closes #12710

Add Project.where_paths_in

In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4410 I'm working on reducing the SQL queries needed to render Markdown. One reason for the large amount of queries is executing a large number of queries needed to find projects and related data. Basically `Project.find_with_namespace` is called in a loop and then any relations have to be retrieved separately.

By using `Project.where_paths_in` we can work around this by doing something like:

```ruby
project_paths = [...] # populated by some method
projects = Project.where_paths_in(project_paths).includes(:namespace, ...)
```

Ref: https://gitlab.com/gitlab-org/gitlab-ce/issues/18042

See merge request !4535

Changelog fix for search dropdown arrow keys fix

[ci skip]

See merge request !4580

Remove unused MergeRequest#gitlab_merge_status method

Closes #18462.

See merge request !4593

Move Labels and Milestones as sub tab to Issues/MR

## What does this MR do?

UI/UX change. Moves project labels and milestone tabs under Issues and Merge request tabs. 

## Why was this MR needed?

To solve problem of having to many tabs in top navigation. Since Labels and Milestones depends on Issue/MR feature it belongs to it and can be removed from top nav.

## What are the relevant issue numbers?

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/18368

## 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) - not needed
- [x] API support added - not needed
- [x] Tests
  - [x] Added for this feature/bug - changed existing tests to match new behaviour
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)

cc @jschatz1 @annabeldunstone @skyruler

See merge request !4592

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

Add workhorse controller and API helpers

Adds `send_git_blob` and `send_git_archive` controller and API helpers to reduce duplication and make Workhorse easier for a developer to work with.

See merge request !4486

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

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

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

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

CI build page UI update

Closes #2569 

See merge request !3829

Update activity SVG path

## What does this MR do?
Fixes SVG path so the activity icon is the correct color

## Screenshots (if relevant)
<img src="/uploads/ea948338ea816890851a8011b8b3255f/Screen_Shot_2016-06-09_at_8.43.05_AM.png" width="600px">


See merge request !4563

Made the awardable buttons prettier when active

## What does this MR do?

Made the active and hover state of the award emoji buttons prettier.

## Why was this MR needed?

'cause @JobV wanted them to look nicer 😉 

## What are the relevant issue numbers?

Closes #18379 

## Screenshots (if relevant)

![Screen_Shot_2016-06-09_at_09.10.44](/uploads/5ecd0f12679e3484de1ab1d2dbe50cd8/Screen_Shot_2016-06-09_at_09.10.44.png)

See merge request !4554

Correctly shows label errors in dropdown

## What does this MR do?

Correctly shows any errors in the dropdown when creating a new label

## What are the relevant issue numbers?

Closes #18344 

## Screenshots (if relevant)

![Screen_Shot_2016-06-09_at_09.01.59](/uploads/58dc56b39db20a50adce6f12510025fc/Screen_Shot_2016-06-09_at_09.01.59.png)

See merge request !4553

Revert change to search all users

## What does this MR do?

Reverts a change that allowed the user to search for all users in the author/assignee dropdown

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

Double check it isn't still searching all users

See merge request !4564

Fixed project dropdown being overlapped by sidebar

## What does this MR do?

Changes the header expanded `padding` to `margin` to prevent the project dropdown from overlapping.

## What are the relevant issue numbers?

Closes #18410 

## Screenshots (if relevant)

![Screen_Shot_2016-06-10_at_10.38.00](/uploads/b569d6d4cbd126fd776cf849ebc1137d/Screen_Shot_2016-06-10_at_10.38.00.png)

See merge request !4583

Fixed issue where label filtering didnt work

## What does this MR do?

The filterable option was missing which meant labels in the dropdown couldn't be filtered. This fixes that.

## What are the relevant issue numbers?

Closes #18375 

See merge request !4556

Rename Commit to Pipeline in TriggerRequest

Changes in TriggerRequest a `commit` to `pipeline`.


See merge request !4505

Fix incorrect registry key value



See merge request !4595

Cache the presence of an issue_tracker at project level

See merge request !4466

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/18441

Using update_column to store the boolean flag to avoid
any side effects with the current state of the project
instance

This method can be used to find multiple projects for multiple paths.
For example, take this snippet:

    Project.where_paths_in(%w{gitlab-org/gitlab-ce gitlab-org/gitlab-ee})

This will return an ActiveRecord::Relation containing the GitLab CE and
GitLab EE projects.

This method takes care of matching rows both case-sensitively and
case-insensitively where needed.

Project.find_with_namespace in turn has been modified to use
Project.where_paths_in without nuking any scoping (instead it uses
reorder(nil)). This means that any default scopes (e.g. those used for
"pending_delete" stay intact).

The method Project.where_paths_in was added so the various Markdown
filters can use a single query to grab all the projects referenced in a
set of documents, something Project.find_with_namespace didn't allow.

Fix UTF-8 handling in incremental trace update API

## What does this MR do?

This MR fixes invalid UTF-8 handling in incremental trace update API (used by GitLab Runner).

## Why was this MR needed?

Current version is using `.length` method to determine current trace size where Runner is using the trace size in bytes. Also this byte size is used in headers and file operations to agree the trace part to send. This is a problem when build trace contains any multi-byte UTF-8 characters. This MR is fixing this situation so all parts are using the same size in bytes.

### Runner -> API communication before fix:
```
Checking for builds... received                     runner=_token_
gitlab-ci-multi-runner 1.3.0~beta.26.gcfd63b9 (cfd63b9)  build=25 runner=_token_
Using Docker executor with image debian:jessie ...  build=25 runner=_token_
Pulling docker image debian:jessie ...              build=25 runner=_token_
25 Submitting build to coordinator... ok            runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-158 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=0-158 runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-491 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=158-505 runner=_token_
WARNING: 25 Appending trace to coordinator... range missmatch  RemoteRange=0-491 RemoteState= ResponseMessage=416 Requested Range Not Satisfiable ResponseStatusCode=416 SentRange=505-584 runner=_token_
WARNING: 25 Resending trace patch due to range missmatch  runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-556 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=491-584 runner=_token_
WARNING: 25 Appending trace to coordinator... range missmatch  RemoteRange=0-556 RemoteState= ResponseMessage=416 Requested Range Not Satisfiable ResponseStatusCode=416 SentRange=584-663 runner=_token_
WARNING: 25 Resending trace patch due to range missmatch  runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-621 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=556-663 runner=_token_
Build succeeded                                     build=25 runner=_token_
WARNING: 25 Appending trace to coordinator... range missmatch  RemoteRange=0-621 RemoteState= ResponseMessage=416 Requested Range Not Satisfiable ResponseStatusCode=416 SentRange=663-797 runner=_token_
WARNING: 25 Resending trace patch due to range missmatch  runner=_token_
25 Appending trace to coordinator... ok             RemoteRange=0-741 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=621-797 runner=_token_
25 Submitting build to coordinator... ok            runner=_token_
```

### Runner -> API communication after fix:
```
Checking for builds... received                     runner=_token_
gitlab-ci-multi-runner 1.3.0~beta.26.gcfd63b9 (cfd63b9)  build=26 runner=_token_
Using Docker executor with image debian:jessie ...  build=26 runner=_token_
Pulling docker image debian:jessie ...              build=26 runner=_token_
26 Submitting build to coordinator... ok            runner=_token_
26 Appending trace to coordinator... ok             RemoteRange=0-158 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=0-158 runner=_token_
26 Appending trace to coordinator... ok             RemoteRange=0-505 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=158-505 runner=_token_
26 Appending trace to coordinator... ok             RemoteRange=0-584 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=505-584 runner=_token_
26 Appending trace to coordinator... ok             RemoteRange=0-663 RemoteState=running ResponseMessage=202 Accepted ResponseStatusCode=202 SentRange=584-663 runner=_token_
Build succeeded                                     build=26 runner=_token_
26 Submitting build to coordinator... ok            runner=_token_
```

See merge request !4541

Add option to restrict merge MR with failed build

_Originally opened at !3828 by @ruianderson._

-----

## What does this MR do?

This MR adds an option to prevent MR from being merged if their build status is not a success. Please note that if the MR has no `ci_commit`, the MR can be merged (i.e. we don't enforce builds to be configured).

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

Probably the copy in the edit project's page and in the documentation.

## What are the relevant issue numbers?

Closes #5940.

## Screenshots

![only_allow_merge_if_build_succeeds](/uploads/bb43cf131f680c9af0eb2ea5155189e0/only_allow_merge_if_build_succeeds.png)

See merge request !4503

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

The logic of the method was obviously inverted.
Signed-off-by: Rémy Coutable <remy@rymai.me>

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

Based on the feedback from reviewers.
Signed-off-by: Rémy Coutable <remy@rymai.me>

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

Don't require Gitlab::Redis in mail_room.yml if it's already defined

## What does this MR do?

Avoid requiring `lib/gitlab/redis.rb` if `Gitlab::Redis` is already defined.

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

No.

## Why was this MR needed?

Because otherwise you get `already initialized constant Gitlab::Redis::XXX`, e.g.:

```
› bin/rspec spec/config/mail_room_spec.rb
Running via Spring preloader in process 24658
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:3: warning: already initialized constant Gitlab::Redis::CACHE_NAMESPACE 
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:3: warning: previous definition of CACHE_NAMESPACE was here
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:4: warning: already initialized constant Gitlab::Redis::SESSION_NAMESPACE
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:4: warning: previous definition of SESSION_NAMESPACE was here
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:5: warning: already initialized constant Gitlab::Redis::SIDEKIQ_NAMESPACE
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:5: warning: previous definition of SIDEKIQ_NAMESPACE was here
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:12: warning: already initialized constant Gitlab::Redis::URL_MUTEX
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:12: warning: previous definition of URL_MUTEX was here
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:13: warning: already initialized constant Gitlab::Redis::POOL_MUTEX
/Users/remy/Code/GitLab/gdk/gitlab/lib/gitlab/redis.rb:13: warning: previous definition of POOL_MUTEX was here
 2/2 |================================================= 100 =================================================>| Time: 00:00:00 

Finished in 0.38505 seconds (files took 0.48292 seconds to load)
2 examples, 0 failures
```

## What are the relevant issue numbers?

None!

## Does this MR meet the acceptance criteria?

- [x] ~~[CHANGELOG](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CHANGELOG) entry added~~ Not needed.
- [x] ~~[Documentation created/updated](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/doc/development/doc_styleguide.md)~~ Not needed.
- [x] ~~API support added.~~ Not needed.
- [x] ~~Tests.~~ Not needed.
- [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 !4586

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