documentation: fixes to source installation instructions

Closes #47483

See merge request gitlab-org/gitlab-ce!21359

Fix remote mirrors failing if Git remotes have not been added

Closes #50562

See merge request gitlab-org/gitlab-ce!21351

Fix transient failure of badge_list_spec.js

See merge request gitlab-org/gitlab-ce!21363

Backport LDAP changes to CE

See merge request gitlab-org/gitlab-ce!21361

Merge branch '43096-controller-projects-issuescontroller-referenced_merge_requests-json-executes-more-than-100-sql-queries' into 'master'

Resolve "Controller Projects::IssuesController#referenced_merge_requests.json executes more than 100 SQL queries"

Closes #43096

See merge request gitlab-org/gitlab-ce!21237

Finish cleaning up reassigned variables

Closes #49807

See merge request gitlab-org/gitlab-ce!21349

Fixes doc/development/architecture.md prod links.

See merge request gitlab-org/gitlab-ce!20455

"/home/git/repositories" in arguments causes Gitaly installation to fail

Speed up diff comparisons by limiting number of commit messages rendered

See merge request gitlab-org/gitlab-ce!21335

Added count for label, assignee, and milestone lists

Closes #48800

See merge request gitlab-org/gitlab-ce!21208

Add public/uploads/tmp to allowed upload paths

Closes #49585

See merge request gitlab-org/gitlab-ce!20942

Remote mirrors only get created when the URL changes, However, during the GCP
migration, the remote mirror did not get created automatically. Plus, there's
no guarantee someone restoring a repository from backup would have this
remote. We now add the remote each time we attempt to fetch from the
repository.

This works because Gitaly doesn't throw up an exception or error if the
remote already exists:
https://gitlab.com/gitlab-org/gitaly/issues/1317

In the future, we should attempt to add if the remote doesn't exist:
https://gitlab.com/gitlab-org/gitaly/issues/1316

Closes #50562

[ci skip]

Fix broken Git over HTTP clones with LDAP users

Closes #50579

See merge request gitlab-org/gitlab-ce!21352

Fix wrong commit count in push event payload

Closes #49971

See merge request gitlab-org/gitlab-ce!21338

Due to a regression in !20608, the LDAP authenticator was not being used
unless OmniAuth was enabled. This change allows the LDAP provider to be used
if it is configured regardless of the OmniAuth setting.

Closes #50579

This fixes a regression in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20916.
We now only use the full commit count for the initial push to the default branch.
Otherwise, we rely on the number of commits that we calculated occurred in the push.

The original behavior in 11.1.4:

1. When a new branch is pushed, `@push_commits_count` was set to the total
number of refs available for the branch.
2. For other branches, `@push_commits_count` would remain `nil`.
3. `GitPushService#build_push_data` would build the push data with
`@push_commits_count`.
4. If this were `nil`, it would be set to the right value here:
https://gitlab.com/gitlab-org/gitlab-ce/blob/v11.1.4/lib/gitlab/data_builder/push.rb#L60

Broken behavior:

1. `GitPushService#push_commits_count` is always called.
2. The total number of commits is therefore always equal to the total number of refs available.

Closes https://gitlab.com/gitlab-org/gitlab-ce/issues/49971

Improve system hook spec in spec/services/git_push_service_spec.rb

See merge request gitlab-org/gitlab-ce!21347

Update gitlab-svgs to 1.2.8

See merge request gitlab-org/gitlab-ce!21346

When a diff has a significant number of commits, the previous behavior would
attempt to render the Markdown on all the commit messages but only display
1000 of them. To avoid additional work, we only need to render the Markdown
on the set that is displayed.

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

Eliminate unnecessary and duplicate system hook fires

Closes #50549

See merge request gitlab-org/gitlab-ce!21337

Added store for file templates in the Web IDE

See merge request gitlab-org/gitlab-ce!21272

[QA] Fix a 'superclass must be a Class' error

Closes gitlab-qa#317

See merge request gitlab-org/gitlab-ce!21340

Avoid nil safe message

See merge request gitlab-org/gitlab-ce!21326

Bump fog-google to 1.7.1 and google-api-client to 0.23.0

See merge request gitlab-org/gitlab-ce!21295

Resolve "Cherry-picking: Confirmation message should include target branch name"

Closes #41441

See merge request gitlab-org/gitlab-ce!20846

API: Catch empty commit messages

Closes #50268, #50266, and #50265

See merge request gitlab-org/gitlab-ce!21322

Api empty project snippets

Closes #50270

See merge request gitlab-org/gitlab-ce!21325

API: Add shared project's expiration date

Closes #46107

See merge request gitlab-org/gitlab-ce!21104

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

[ci skip]

Docs update ha aws diagram

See merge request gitlab-org/gitlab-ce!21321