fix pagination component handling different header styles from different server proxies

See merge request !8569

Allow to use '+' symbol in filenames

Closes #22859

See merge request !6644

Use string for class_name option for lazy autoload class

See merge request !8580

existing folders and existing repos should not use the same set of instructions …

See merge request !3446

use plain shell

See merge request !3509

Passing constant into this option is deprecated in Rails 5.2
https://github.com/rails/rails/commit/8312a0d22212798864f142b5a94805e0baa6c562

Mutate the attribute instead of issuing a write operation to the DB in `ProjectFeaturesCompatibility` concern.

Closes gitlab-ee#1520

See merge request !8552

Merge branch '25018-gitlab-checks-changeaccess-looks-for-user-permissions-that-don-t-exist' into 'master'

Resolve "`Gitlab::Checks::ChangeAccess` looks for user permissions that don't exist"

Closes #25018

See merge request !8551

Resolve "Metrics middleware:  endpoint is nil"

Closes #26587

See merge request !8544

Resolve "Sort order for pipeline build lists doesn't properly handle numbers"

Closes #25428

See merge request !8277

Improve single mattermost team select disabled state

See merge request !8276

Merge separate build spec files into one in correct location

Closes #24579

See merge request !8564

Add tests

Update commit entity to point to valid commit page

Closes #26624

See merge request !8558

Fix broken link in docs

Closes #26544

[ci skip]

See merge request !8529

Allow to use ENV variables in redis config

See merge request !8073

Fixed spacing of labels in issuable row on milestone#show

See merge request !8563

Fix milestone API specs in Ruby 2.1

See merge request !8555

[ci skip]

This is less invasive than the parent commit.

Ruby 2.3:
```
URI.parse('http://foo/bar?baz quux')
=> #<URI::HTTP http://foo/bar?baz%20quux>
```

Ruby 2.1:
```
URI.parse('http://foo/bar?baz quux')
URI::InvalidURIError: bad URI(is not URI?): http://foo/bar?baz quux
```

Add check for new path existence

Closes #26641

See merge request !8554

Copy <some text> to clipboard

See merge request !8535

Fixes the incoherent filtering by milestone in `/projects/:id/issues` and `/groups/:id/issues` endpoints

Closes #23194

See merge request !8457

Update gitlab-markup back to 1.5.1 in Gemfile

Closes #26627

See merge request !8550

Move dashboard help spinach test to rspec

See merge request !8436

Move dashboard group spinach test to rspec

See merge request !8434