The function `#commits_for()` has been introduced via 156ce433
(checks: Implement infrastructure for bulk diff checks, 2021-07-29) in
order to allow bulk-loading of commits. What this function does is given
a set of new commits and a specific object ID, it will do a graph walk
of these new commits starting from this ID in order to extract only
those commits which have been newly introduced via this object ID.

As it turns out though, the implementation has a bug which causes
combinatorial explosion: if a commit is reachable via multiple commits,
then it will be walked and returned multiple times. This can happen if
there are merge commits, where we'll now repeatedly walk all common
ancestors of both commits. In case these again contain merge commits,
the common ancestors again get walked multiple times. The result is that
commits get walked exponentially many times. For the following graph
with criss-cross merges, this causes us to return 768 commits instead of
the expected 18:

      o---o---o---o---o---o---o---o
     / \ / \ / \ / \ / \ / \ / \ / \
    o   X   X   X   X   X   X   X   o
    \  / \ / \ / \ / \ / \ / \ / \ /
      o---o---o---o---o---o---o---o

Fix the bug by removing seen commit IDs from the hash tracking commits
by their object ID. Furthermore, the pending queue is converted to a set
such that we don't re-add IDs which we have already seen before such
that it doesn't exhibit exponential growth.

Changelog: fixed

`#commits_for()` has a bug where commits are returned multiple times in
case they're reachable via multiple commits, leading to combinatorial
explosion. Add a testcase which demonstrates this bug.

Filter suggested users by saml provider in invite modal dropdown list [RUN ALL RSPEC] [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!63565

Filter suggested users by saml provider in invite modal dropdown list [RUN ALL RSPEC] [RUN AS-IF-FOSS]

Integrate instance-level with group-level MR approval settings

See merge request gitlab-org/gitlab!67316

Remove sec_dependency_scanning_ui_enable Feature Flag

See merge request gitlab-org/gitlab!67585

Render emojis in the Content Editor

See merge request gitlab-org/gitlab!67986

Move validation logic from Vue component to resolvers

See merge request gitlab-org/gitlab!67836

Bump factory_bot_rails for Ruby3 support [RUN ALL RSPEC]

See merge request gitlab-org/gitlab!67866

Move value to constants

See merge request gitlab-org/gitlab!68011

Include Puma worker PID in structured log [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!66694

Changelog: other

Additional namespace validation for AdditionalPack

See merge request gitlab-org/gitlab!67848

Update quarantine reason

See merge request gitlab-org/gitlab!67871

Document how DS handles multiple lockfiles

See merge request gitlab-org/gitlab!66886

Use http read total timeout by default

See merge request gitlab-org/gitlab!66487

Add the four primary work item types to DB - issue, incident, test_case, and requirement

See merge request gitlab-org/gitlab!67434

in preparation for moving issue_type column.
Add the default work item types to the work item type table.

Changelog: changed

Enabled diff virtual scrolling by default

See merge request gitlab-org/gitlab!67983

Count epics against issue creation rate limit

See merge request gitlab-org/gitlab!67179

DB testing: Refactor to have stateful observers per migration

See merge request gitlab-org/gitlab!65777

Fix Rubocop Graphql/Description offenses [RUN AS-IF-FOSS]

See merge request gitlab-org/gitlab!67912

Modify CSP when Sentry is configured

See merge request gitlab-org/gitlab!67791

Add rules support for CI pipeline include

See merge request gitlab-org/gitlab!67409

E2E: Update bulk group import via api spec

See merge request gitlab-org/gitlab!67946

Changelog: changed
MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/67179
EE: true

Updated nav to match standards

See merge request gitlab-org/gitlab!68019

Update Ruby.gitlab-ci.yml for new vendor path

See merge request gitlab-org/gitlab!67919

Related to: https://gitlab.com/gitlab-org/technical-writing/-/issues/454

https://gitlab.com/gitlab-org/gitlab/-/issues/337596

Make Gitlab::BackgroundMigration.remaining work across queues

See merge request gitlab-org/gitlab!67432

Render artifact download buttonas for all security report types

See merge request gitlab-org/gitlab!67701

Resolve "Linear Project#ancestors"

See merge request gitlab-org/gitlab!67565

Fix policies drawer header height for list page

See merge request gitlab-org/gitlab!67905

A few more edits for clarity and style

See merge request gitlab-org/gitlab!68008