For background see
https://apidock.com/rails/v4.2.7/ActiveRecord/Relation/find_or_create_by.

This is to avoid a mix-up with the existing concept of 'user
contributions'. See `User#contributed_projects` or
`Event#contributions`.

This is only relevant for migration specs. See
spec/support/migrations_helpers.rb.

This is due to the problem that the callback can be called while running
an earlier database schema version (for example during earlier
migrations). We work around this by checking the current schema version
and only track contributions if the table is available.

* Event without project
* Fail early on unexpectedly missing author

Closes #43460.

MySQL does not return the number of inserted rows (or at least not
expose them through cmd_tuples). Let's do one-shot INSERT instead.

Trying to be a good citizen here, we spread the load building that
table. Maybe not required, but at least good practice and no harm.

Cleanup after adding MR diff's commit_count

Closes #41698

See merge request gitlab-org/gitlab-ce!17513

Remove impersonate token from flash scope in UI

See merge request gitlab-org/gitlab-ce!17480

Keep note commit around if commit_id is present

Closes gitaly#1054

See merge request gitlab-org/gitlab-ce!17496

Port Labels Select dropdown to Vue

See merge request gitlab-org/gitlab-ce!17411

Try not to hold env and release the controller after the request.

See merge request gitlab-org/gitlab-ce!16847

Closes gitaly#1054

Resolve "Not seeing "mentioned in commit" system message after merging"

Closes #43809

See merge request gitlab-org/gitlab-ce!17524

Incorporate Gitaly's RPCs for Gitlab::Git::LfsChanges

Closes gitaly#1048

See merge request gitlab-org/gitlab-ce!16973

Add support for :all option to {count,find}_commits

See merge request gitlab-org/gitlab-ce!17464

Render htmlentities correctly for links not supported by Rinku

Closes #41719

See merge request gitlab-org/gitlab-ce!17180

New `/wip` quick action on MR creation

Closes #26848

See merge request gitlab-org/gitlab-ce!17463

Merge branch '37430-projects-comparecontroller-show-is-calling-gitaly-n-1-times-per-request' into 'master'

Resolve "Projects::CompareController#show is calling Gitaly n+1 times per request"

Closes #37430

See merge request gitlab-org/gitlab-ce!17439

#43691: DiffNotes not counted by ContributionsCalendar

Closes #43691

See merge request gitlab-org/gitlab-ce!17418

Loading spinner not stop even on errors in updating Milestone on Issue

Closes #43837

See merge request gitlab-org/gitlab-ce!17507

* processes any pending records which are not migrated yet
* bumps import_export version because of new commits_count attribute
* removes commits_count fallback method

Ports https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/4747 to CE

See merge request gitlab-org/gitlab-ce!17520

Resolve "API support for selecting only  updated issues before/after a given date"

Closes #41616

See merge request gitlab-org/gitlab-ce!17417