Previously, we were checking that a CSS selector string didn't have some
page-related content, which, of course it didn't.

Now we check against the actual content of the selector, we use a more
semantic selector, and we add an additional expectation for the text
that _should_ be there, as an additional sanity check.

gitlab_git 10.6.4 relies on Rugged marking blobs as binary or not,
instead of relying on Linguist. Linguist in turn would mark text blobs
as binary whenever they would contain byte sequences that could not be
encoded using UTF-8.

However, marking such blobs as binary is not correct. If one pushes a
Markdown document with invalid character sequences it's still a text
based Markdown document and not some random binary blob.

This commit overwrites Blob#data so it automatically converts text-based
content to UTF-8 (the encoding we use everywhere else) while taking care
of replacing any invalid sequences with the UTF-8 replacement character.
The data of binary blobs is left as-is.

add tests with dependent destroy

add tests with dependent destroy

add tests

add tests to projects spec

update it title  and remove let

update it title  and remove let

remove changes after rebase

remove changes after rebase

update changelog

This moves tracking of the pushes since the last Git GC from PostgreSQL
to Redis. This reduces the number of writes on the "projects" table.
This in turn reduces the vacuuming overhead.

The lease used for incrementing the counter has been removed. This lease
was mostly put in place to prevent high database load but this isn't
needed anymore due to the counter now being stored in Redis.

Fixes gitlab-org/gitlab-ce#22125

https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/6305#note_15230024

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/21823

The observed faulty state transition is probably hard to test,
because we need to hook into internal states to observe them.
Namely this:

    07:30:16 | Build#ruby-2.2 enqueue: created -> pending
    07:30:16 | Pipeline#32    enqueue: created -> pending
    07:30:16 | Build#ruby-2.3 enqueue: created -> pending
    07:30:16 | Build#ruby-2.2     run: pending -> running
    07:30:16 | Pipeline#32        run: pending -> running
    07:30:29 | Build#ruby-2.2    drop: running -> failed
    07:30:29 | Pipeline#32        run: running -> running
    07:30:29 | Build#ruby-2.3     run: pending -> running
    07:30:30 | Pipeline#32        run: running -> running
    07:30:57 | Build#gem:build   skip: created -> skipped
    07:30:57 | Pipeline#32       drop: running -> failed
    07:30:57 | Build#gem:release skip: created -> skipped
    07:30:57 | Pipeline#32       drop:  failed -> failed
    07:30:57 | Build#ruby-2.3    drop: running -> failed
    07:30:57 | Pipeline#32       drop: running -> failed
                                       ^^^ Should be failed -> failed

However, the consequence of this, executing hooks twice would be
easy enough to observe. So we could at least test against this.
Keep in mind that if we ever changed how we execute the hooks
this won't be testing against faulty state transition.

# Conflicts:
#	lib/gitlab/github_import/importer.rb

MySQL could not have support for millisecond precision, depends on the MySQL version 
so we just create issues in different seconds in a deterministic way

Fixes failed builds such as https://gitlab.com/gitlab-org/gitlab-ce/builds/3919501

Use NotificationSetting::EMAIL_EVENTS for params

Closes #21982