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

Move dashboard archived projects spinach tests to rspec

See merge request !8431