Add latest changes from gitlab-org/gitlab@master

29 files changed, 505 insertions, 291 deletions

diff --git a/.gitlab/ci/reports.gitlab-ci.yml b/.gitlab/ci/reports.gitlab-ci.yml
index 964aa8e523f..688cfb5033e 100644
--- a/.gitlab/ci/reports.gitlab-ci.yml
+++ b/.gitlab/ci/reports.gitlab-ci.yml
@@ -168,6 +168,7 @@ dast:
     # DAST_USERNAME: "root"
     # DAST_USERNAME_FIELD: "user[login]"
     # DAST_PASSWORD_FIELD: "user[passowrd]"
+    DAST_VERSION: 1
   allow_failure: true
   script:
     - 'export DAST_WEBSITE="${DAST_WEBSITE:-$(cat environment_url.txt)}"'
diff --git a/app/assets/javascripts/boards/components/board_card.vue b/app/assets/javascripts/boards/components/board_card.vue
index 12d68256598..0fc60528eb6 100644
--- a/app/assets/javascripts/boards/components/board_card.vue
+++ b/app/assets/javascripts/boards/components/board_card.vue
@@ -65,11 +65,12 @@ export default {
     },
     showIssue(e) {
       if (e.target.classList.contains('js-no-trigger')) return;
-      if (this.showDetail) {
-        this.showDetail = false;
 
-        // If CMD or CTRL is clicked
-        const isMultiSelect = this.canMultiSelect && (e.ctrlKey || e.metaKey);
+      // If CMD or CTRL is clicked
+      const isMultiSelect = this.canMultiSelect && (e.ctrlKey || e.metaKey);
+
+      if (this.showDetail || isMultiSelect) {
+        this.showDetail = false;
 
         if (boardsStore.detail.issue && boardsStore.detail.issue.id === this.issue.id) {
           eventHub.$emit('clearDetailIssue', isMultiSelect);
diff --git a/app/assets/javascripts/frequent_items/components/frequent_items_list_item.vue b/app/assets/javascripts/frequent_items/components/frequent_items_list_item.vue
index 3276d85f1cd..c0dadedbc51 100644
--- a/app/assets/javascripts/frequent_items/components/frequent_items_list_item.vue
+++ b/app/assets/javascripts/frequent_items/components/frequent_items_list_item.vue
@@ -1,6 +1,5 @@
 <script>
 /* eslint-disable vue/require-default-prop */
-import { isEmpty, isString } from 'lodash';
 import Identicon from '~/vue_shared/components/identicon.vue';
 import highlight from '~/lib/utils/highlight';
 import { truncateNamespace } from '~/lib/utils/text_utility';
@@ -38,9 +37,6 @@ export default {
     },
   },
   computed: {
-    hasAvatar() {
-      return isString(this.avatarUrl) && !isEmpty(this.avatarUrl);
-    },
     truncatedNamespace() {
       return truncateNamespace(this.namespace);
     },
@@ -54,8 +50,11 @@ export default {
 <template>
   <li class="frequent-items-list-item-container">
     <a :href="webUrl" class="clearfix">
-      <div class="frequent-items-item-avatar-container avatar-container rect-avatar s32">
-        <img v-if="hasAvatar" :src="avatarUrl" class="avatar s32" />
+      <div
+        ref="frequentItemsItemAvatarContainer"
+        class="frequent-items-item-avatar-container avatar-container rect-avatar s32"
+      >
+        <img v-if="avatarUrl" ref="frequentItemsItemAvatar" :src="avatarUrl" class="avatar s32" />
         <identicon
           v-else
           :entity-id="itemId"
@@ -64,16 +63,18 @@ export default {
           class="rect-avatar"
         />
       </div>
-      <div class="frequent-items-item-metadata-container">
+      <div ref="frequentItemsItemMetadataContainer" class="frequent-items-item-metadata-container">
         <div
+          ref="frequentItemsItemTitle"
           :title="itemName"
-          class="frequent-items-item-title js-frequent-items-item-title"
+          class="frequent-items-item-title"
           v-html="highlightedItemName"
         ></div>
         <div
           v-if="namespace"
+          ref="frequentItemsItemNamespace"
           :title="namespace"
-          class="frequent-items-item-namespace js-frequent-items-item-namespace"
+          class="frequent-items-item-namespace"
         >
           {{ truncatedNamespace }}
         </div>
diff --git a/app/assets/javascripts/ide/components/nav_dropdown_button.vue b/app/assets/javascripts/ide/components/nav_dropdown_button.vue
index 4cd320d5d66..8dc22620eca 100644
--- a/app/assets/javascripts/ide/components/nav_dropdown_button.vue
+++ b/app/assets/javascripts/ide/components/nav_dropdown_button.vue
@@ -31,8 +31,8 @@ export default {
 
 <template>
   <dropdown-button>
-    <span class="row">
-      <span class="col-auto text-truncate" :class="{ 'col-7': showMergeRequests }">
+    <span class="row flex-nowrap">
+      <span class="col-auto flex-fill text-truncate">
         <icon :size="16" :aria-label="__('Current Branch')" name="branch" /> {{ branchLabel }}
       </span>
       <span v-if="showMergeRequests" class="col-5 pl-0 text-truncate">
diff --git a/app/assets/javascripts/right_sidebar.js b/app/assets/javascripts/right_sidebar.js
index fa5649679d7..550ec3cb0d1 100644
--- a/app/assets/javascripts/right_sidebar.js
+++ b/app/assets/javascripts/right_sidebar.js
@@ -1,4 +1,4 @@
-/* eslint-disable func-names, consistent-return, no-else-return, no-param-reassign */
+/* eslint-disable func-names, consistent-return, no-param-reassign */
 
 import $ from 'jquery';
 import _ from 'underscore';
@@ -34,8 +34,6 @@ Sidebar.prototype.addEventListeners = function() {
 
   this.sidebar.on('click', '.sidebar-collapsed-icon', this, this.sidebarCollapseClicked);
   this.sidebar.on('hidden.gl.dropdown', this, this.onSidebarDropdownHidden);
-  $('.dropdown').on('loading.gl.dropdown', this.sidebarDropdownLoading);
-  $('.dropdown').on('loaded.gl.dropdown', this.sidebarDropdownLoaded);
 
   $document.on('click', '.js-sidebar-toggle', this.sidebarToggleClicked);
   return $(document)
@@ -133,36 +131,6 @@ Sidebar.prototype.todoUpdateDone = function(data) {
   });
 };
 
-Sidebar.prototype.sidebarDropdownLoading = function() {
-  const $sidebarCollapsedIcon = $(this)
-    .closest('.block')
-    .find('.sidebar-collapsed-icon');
-  const img = $sidebarCollapsedIcon.find('img');
-  const i = $sidebarCollapsedIcon.find('i');
-  const $loading = $('<i class="fa fa-spinner fa-spin"></i>');
-  if (img.length) {
-    img.before($loading);
-    return img.hide();
-  } else if (i.length) {
-    i.before($loading);
-    return i.hide();
-  }
-};
-
-Sidebar.prototype.sidebarDropdownLoaded = function() {
-  const $sidebarCollapsedIcon = $(this)
-    .closest('.block')
-    .find('.sidebar-collapsed-icon');
-  const img = $sidebarCollapsedIcon.find('img');
-  $sidebarCollapsedIcon.find('i.fa-spin').remove();
-  const i = $sidebarCollapsedIcon.find('i');
-  if (img.length) {
-    return img.show();
-  } else {
-    return i.show();
-  }
-};
-
 Sidebar.prototype.sidebarCollapseClicked = function(e) {
   if ($(e.currentTarget).hasClass('dont-change-state')) {
     return;
diff --git a/app/assets/javascripts/vue_merge_request_widget/components/deployment/deployment_view_button.vue b/app/assets/javascripts/vue_merge_request_widget/components/deployment/deployment_view_button.vue
index 18d4073ecd4..e1a1b1022e3 100644
--- a/app/assets/javascripts/vue_merge_request_widget/components/deployment/deployment_view_button.vue
+++ b/app/assets/javascripts/vue_merge_request_widget/components/deployment/deployment_view_button.vue
@@ -1,4 +1,5 @@
 <script>
+import { GlLink } from '@gitlab/ui';
 import FilteredSearchDropdown from '~/vue_shared/components/filtered_search_dropdown.vue';
 import ReviewAppLink from '../review_app_link.vue';
 
@@ -6,6 +7,7 @@ export default {
   name: 'DeploymentViewButton',
   components: {
     FilteredSearchDropdown,
+    GlLink,
     ReviewAppLink,
     VisualReviewAppLink: () =>
       import('ee_component/vue_merge_request_widget/components/visual_review_app_link.vue'),
@@ -67,7 +69,7 @@ export default {
       </template>
 
       <template slot="result" slot-scope="slotProps">
-        <a
+        <gl-link
           :href="slotProps.result.external_url"
           target="_blank"
           rel="noopener noreferrer nofollow"
@@ -80,16 +82,15 @@ export default {
           <p class="text-secondary str-truncated-100 append-bottom-0 d-block">
             {{ slotProps.result.external_url }}
           </p>
-        </a>
+        </gl-link>
       </template>
     </filtered-search-dropdown>
-    <template v-else>
-      <review-app-link
-        :display="appButtonText"
-        :link="deploymentExternalUrl"
-        css-class="js-deploy-url deploy-link btn btn-default btn-sm inline"
-      />
-    </template>
+    <review-app-link
+      v-else
+      :display="appButtonText"
+      :link="deploymentExternalUrl"
+      css-class="js-deploy-url deploy-link btn btn-default btn-sm inline"
+    />
     <visual-review-app-link
       v-if="showVisualReviewApp"
       :link="deploymentExternalUrl"
diff --git a/changelogs/unreleased/13810-cluster-environments-table.yml b/changelogs/unreleased/13810-cluster-environments-table.yml
new file mode 100644
index 00000000000..bbcebec9106
--- /dev/null
+++ b/changelogs/unreleased/13810-cluster-environments-table.yml
@@ -0,0 +1,5 @@
+---
+title: Add responsivity to cluster environments table
+merge_request: 25501
+author:
+type: fixed
diff --git a/changelogs/unreleased/195969-multi-select-on-issue-boards-inconsistent-erratic.yml b/changelogs/unreleased/195969-multi-select-on-issue-boards-inconsistent-erratic.yml
new file mode 100644
index 00000000000..614379d7ad8
--- /dev/null
+++ b/changelogs/unreleased/195969-multi-select-on-issue-boards-inconsistent-erratic.yml
@@ -0,0 +1,5 @@
+---
+title: Improved selection of multiple cards
+merge_request:
+author: Gwen_
+type: fixed
diff --git a/changelogs/unreleased/205435.yml b/changelogs/unreleased/205435.yml
new file mode 100644
index 00000000000..c004bdf35c3
--- /dev/null
+++ b/changelogs/unreleased/205435.yml
@@ -0,0 +1,5 @@
+---
+title: Clean up conditional `col-` classes in `nav_dropdown_button.vue`
+merge_request: 25312
+author:
+type: other
diff --git a/changelogs/unreleased/28560_cleanup_optimistic_locking_db.yml b/changelogs/unreleased/28560_cleanup_optimistic_locking_db.yml
new file mode 100644
index 00000000000..30d1b6ce94d
--- /dev/null
+++ b/changelogs/unreleased/28560_cleanup_optimistic_locking_db.yml
@@ -0,0 +1,5 @@
+---
+title: Set all NULL `lock_version` values to 0 for issuables
+merge_request: 18418
+author:
+type: fixed
diff --git a/db/post_migrate/20200128210353_cleanup_optimistic_locking_nulls.rb b/db/post_migrate/20200128210353_cleanup_optimistic_locking_nulls.rb
new file mode 100644
index 00000000000..8bc037c7333
--- /dev/null
+++ b/db/post_migrate/20200128210353_cleanup_optimistic_locking_nulls.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+# See http://doc.gitlab.com/ce/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class CleanupOptimisticLockingNulls < ActiveRecord::Migration[5.2]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  disable_ddl_transaction!
+
+  TABLES = %w(epics merge_requests issues).freeze
+  BATCH_SIZE = 10_000
+
+  def declare_class(table)
+    Class.new(ActiveRecord::Base) do
+      include EachBatch
+
+      self.table_name = table
+      self.inheritance_column = :_type_disabled # Disable STI
+    end
+  end
+
+  def up
+    TABLES.each do |table|
+      add_concurrent_index table.to_sym, :lock_version, where: "lock_version IS NULL"
+
+      queue_background_migration_jobs_by_range_at_intervals(
+        declare_class(table).where(lock_version: nil),
+        'CleanupOptimisticLockingNulls',
+        2.minutes,
+        batch_size: BATCH_SIZE,
+        other_arguments: [table]
+      )
+    end
+  end
+
+  def down
+    TABLES.each do |table|
+      remove_concurrent_index table.to_sym, :lock_version, where: "lock_version IS NULL"
+    end
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index 36f15e000f7..0b3eab9797e 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -1574,6 +1574,7 @@ ActiveRecord::Schema.define(version: 2020_02_20_180944) do
     t.index ["end_date"], name: "index_epics_on_end_date"
     t.index ["group_id"], name: "index_epics_on_group_id"
     t.index ["iid"], name: "index_epics_on_iid"
+    t.index ["lock_version"], name: "index_epics_on_lock_version", where: "(lock_version IS NULL)"
     t.index ["parent_id"], name: "index_epics_on_parent_id"
     t.index ["start_date"], name: "index_epics_on_start_date"
     t.index ["start_date_sourcing_epic_id"], name: "index_epics_on_start_date_sourcing_epic_id", where: "(start_date_sourcing_epic_id IS NOT NULL)"
@@ -2193,6 +2194,7 @@ ActiveRecord::Schema.define(version: 2020_02_20_180944) do
     t.index ["confidential"], name: "index_issues_on_confidential"
     t.index ["description"], name: "index_issues_on_description_trigram", opclass: :gin_trgm_ops, using: :gin
     t.index ["duplicated_to_id"], name: "index_issues_on_duplicated_to_id", where: "(duplicated_to_id IS NOT NULL)"
+    t.index ["lock_version"], name: "index_issues_on_lock_version", where: "(lock_version IS NULL)"
     t.index ["milestone_id"], name: "index_issues_on_milestone_id"
     t.index ["moved_to_id"], name: "index_issues_on_moved_to_id", where: "(moved_to_id IS NOT NULL)"
     t.index ["project_id", "created_at", "id", "state"], name: "index_issues_on_project_id_and_created_at_and_id_and_state"
@@ -2611,6 +2613,7 @@ ActiveRecord::Schema.define(version: 2020_02_20_180944) do
     t.index ["id", "merge_jid"], name: "idx_merge_requests_on_id_and_merge_jid", where: "((merge_jid IS NOT NULL) AND (state_id = 4))"
     t.index ["id", "merge_jid"], name: "index_merge_requests_on_id_and_merge_jid", where: "((merge_jid IS NOT NULL) AND ((state)::text = 'locked'::text))"
     t.index ["latest_merge_request_diff_id"], name: "index_merge_requests_on_latest_merge_request_diff_id"
+    t.index ["lock_version"], name: "index_merge_requests_on_lock_version", where: "(lock_version IS NULL)"
     t.index ["merge_user_id"], name: "index_merge_requests_on_merge_user_id", where: "(merge_user_id IS NOT NULL)"
     t.index ["milestone_id"], name: "index_merge_requests_on_milestone_id"
     t.index ["source_branch"], name: "index_merge_requests_on_source_branch"
diff --git a/doc/.linting/vale/styles/gitlab/OxfordComma.yml b/doc/.linting/vale/styles/gitlab/OxfordComma.yml
index c9f4d2895d1..4b37ba8c2b9 100644
--- a/doc/.linting/vale/styles/gitlab/OxfordComma.yml
+++ b/doc/.linting/vale/styles/gitlab/OxfordComma.yml
@@ -8,4 +8,4 @@ message: Use a comma before the last "and" or "or" in a list of four or more ite
 link: https://docs.gitlab.com/ee/development/documentation/styleguide.html#punctuation
 level: warning
 raw:
-  - '(?:[\w-_` ]+,){2,}(?:[\w-_` ]+) (and|or)'
+  - '(?:[\w-_` ]+,){2,}(?:[\w-_` ]+) (and |or )'
diff --git a/doc/.linting/vale/styles/gitlab/SentenceSpacing.yml b/doc/.linting/vale/styles/gitlab/SentenceSpacing.yml
index 5efc6ceeef5..0fc8bfedadc 100644
--- a/doc/.linting/vale/styles/gitlab/SentenceSpacing.yml
+++ b/doc/.linting/vale/styles/gitlab/SentenceSpacing.yml
@@ -1,32 +1,12 @@
 ---
-# `extends` indicates the Vale extension point being used.
-# Full list of styles: https://errata-ai.github.io/vale/styles/
+# Checks the presence of more than one space between sentences or clauses.
+#
+# For a list of all options, see https://errata-ai.github.io/vale/styles/
 extends: existence
-
-# Existence rules can display the matched strings in the user message.
-message: "'%s' should have one space between sentences."
-
-# Should a result be flagged as a suggestion, warning, or error?
-# Results that fall below the MinAlertLevel set in 
-# https://gitlab.com/gitlab-org/gitlab/blob/master/.vale.ini won't be shown.
-level: suggestion
-
-# Should a match be case-insensitive or case-sensitive?
-# Acceptable values are 'true' or 'false'
-# This value is irrelevant when testing non-alphabetical characters
-#ignorecase: true
-
-# Should this rule be limited to a specific scope? If yes, uncomment the line.
-# Possible scopes: https://errata-ai.github.io/vale/formats/#available-scopes
-# scope: heading
-
-# Should this rule ignore normal word boundaries, such as \b ?
-# Acceptable values are 'true' or 'false'
-nonword: true
-
-# What is the source for this rule?
+message: "'%s' should have one space between sentences or clauses."
 link: https://docs.gitlab.com/ee/development/documentation/styleguide.html#punctuation
-
+level: warning
+nonword: true
 tokens:
-  - '[a-z][.?!][A-Z]'
-  - '[.?!] {2,}[A-Z]'
+  - '[a-z][.?!,][A-Z]'
+  - '[.?!,] {2,}[\w]'
diff --git a/doc/README.md b/doc/README.md
index 132351f5353..3efba168f48 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -112,7 +112,7 @@ The following documentation relates to the DevOps **Plan** stage:
 | [Discussions](user/discussions/index.md)                                                                                                                                                                                                                           | Threads, comments, and resolvable threads in issues, commits, and  merge requests.                                                           |
 | [Due Dates](user/project/issues/due_dates.md)                                                                                                                                                                                                                      | Keep track of issue deadlines.                                                                                                                   |
 | [Epics](user/group/epics/index.md) **(ULTIMATE)**                                                                                                                                                                                                                  | Tracking groups of issues that share a theme.                                                                                                    |
-| [Issues](user/project/issues/index.md), including [confidential issues](user/project/issues/confidential_issues.md),<br/>[issue and merge request templates](user/project/description_templates.md),<br/>and [moving issues](user/project/issues/managing_issues.md#moving-issues) | Project issues, restricting access to issues, create templates for submitting new issues and merge requests, and moving issues between projects. |
+| [Issues](user/project/issues/index.md), including [confidential issues](user/project/issues/confidential_issues.md),<br/>[issue and merge request templates](user/project/description_templates.md),<br/>and [moving issues](user/project/issues/managing_issues.md#moving-issues) | Project issues and restricting access to issues as well as creating templates for submitting new issues and merge requests. Also, moving issues between projects. |
 | [Labels](user/project/labels.md)                                                                                                                                                                                                                                   | Categorize issues or merge requests with descriptive labels.                                                                                     |
 | [Milestones](user/project/milestones/index.md)                                                                                                                                                                                                                     | Set milestones for delivery of issues and merge requests, with optional due date.                                                                |
 | [Project Issue Board](user/project/issue_board.md)                                                                                                                                                                                                                 | Display issues on a Scrum or Kanban board.                                                                                                       |
diff --git a/doc/administration/git_protocol.md b/doc/administration/git_protocol.md
index 2e5c362a3ab..b15c3160459 100644
--- a/doc/administration/git_protocol.md
+++ b/doc/administration/git_protocol.md
@@ -4,17 +4,9 @@ description: "Set and configure Git protocol v2"
 
 # Configuring Git Protocol v2
 
-> [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/issues/46555) in GitLab 11.4.
-> Temporarily disabled (see [confidential issue](../user/project/issues/confidential_issues.md)
-> `https://gitlab.com/gitlab-org/gitlab-foss/issues/55769`) in GitLab 11.5.8, 11.6.6, 11.7.1, and 11.8+.
-
-NOTE: **Note:**
-Git protocol v2 support has been temporarily disabled
-because a feature used to hide certain internal references does not function when it
-is enabled, and this has a security impact. Once this problem has been resolved,
-protocol v2 support will be re-enabled. For more information, see the
-[confidential issue](../user/project/issues/confidential_issues.md)
-`https://gitlab.com/gitlab-org/gitlab-foss/issues/55769`.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab-foss/issues/46555) in GitLab 11.4.
+> - [Temporarily disabled](https://gitlab.com/gitlab-org/gitlab-foss/issues/55769) in GitLab 11.5.8, 11.6.6, 11.7.1, and 11.8+.
+> - [Re-enabled](https://gitlab.com/gitlab-org/gitlab/issues/27828) in GitLab 12.8.
 
 Git protocol v2 improves the v1 wire protocol in several ways and is
 enabled by default in GitLab for HTTP requests. In order to enable SSH,
@@ -110,3 +102,15 @@ debug1: Sending env GIT_PROTOCOL = version=2
 
 For the server side, you can use the [same examples from HTTP](#http-connections), changing the
 URL to use SSH.
+
+### Observe Git protocol version of connections
+
+To observe what Git protocol versions are being used in a
+production environment, you can use the following Prometheus query:
+
+```prometheus
+sum(rate(gitaly_git_protocol_requests_total[1m])) by (grpc_method,git_protocol,grpc_service)
+```
+
+You can view what Git protocol versions are being used on GitLab.com at
+<https://dashboards.gitlab.com/d/pqlQq0xik/git-protocol-versions>.
diff --git a/doc/administration/job_artifacts.md b/doc/administration/job_artifacts.md
index 441ad2186f6..0c0be1da3c0 100644
--- a/doc/administration/job_artifacts.md
+++ b/doc/administration/job_artifacts.md
@@ -160,6 +160,11 @@ _The artifacts are stored by default in
    gitlab-rake gitlab:artifacts:migrate
    ```
 
+CAUTION: **CAUTION:**
+JUnit test report artifact (`junit.xml.gz`) migration
+[is not supported](https://gitlab.com/gitlab-org/gitlab/issues/27698)
+by the `gitlab:artifacts:migrate` script.
+
 **In installations from source:**
 
 _The artifacts are stored by default in
@@ -188,6 +193,11 @@ _The artifacts are stored by default in
    sudo -u git -H bundle exec rake gitlab:artifacts:migrate RAILS_ENV=production
    ```
 
+CAUTION: **CAUTION:**
+JUnit test report artifact (`junit.xml.gz`) migration
+[is not supported](https://gitlab.com/gitlab-org/gitlab/issues/27698)
+by the `gitlab:artifacts:migrate` script.
+
 ### Migrating from object storage to local storage
 
 In order to migrate back to local storage:
diff --git a/doc/api/groups.md b/doc/api/groups.md
index 946626859f8..14e04b9dd17 100644
--- a/doc/api/groups.md
+++ b/doc/api/groups.md
@@ -498,7 +498,7 @@ Parameters:
 
 ## Transfer project to group
 
-Transfer a project to the Group namespace. Available only to instance administrators.  Transferring projects may fail when tagged packages exist in the project's repository.
+Transfer a project to the Group namespace. Available only to instance administrators. Transferring projects may fail when tagged packages exist in the project's repository.
 
 ```
 POST  /groups/:id/projects/:project_id
diff --git a/doc/ci/parent_child_pipelines.md b/doc/ci/parent_child_pipelines.md
index 387f2e69606..f8d100b83b8 100644
--- a/doc/ci/parent_child_pipelines.md
+++ b/doc/ci/parent_child_pipelines.md
@@ -80,6 +80,52 @@ microservice_a:
     strategy: depend
 ```
 
+## Merge Request child pipelines
+
+To trigger a child pipeline as a [Merge Request Pipeline](merge_request_pipelines/index.md) we need to:
+
+- Set the trigger job to run on merge requests:
+
+```yaml
+# parent .gitlab-ci.yml
+microservice_a:
+  trigger:
+    include: path/to/microservice_a.yml
+  rules:
+    - if: $CI_MERGE_REQUEST_ID
+```
+
+- Configure the child pipeline by either:
+
+  - Setting all jobs in the child pipeline to evaluate in the context of a merge request:
+
+    ```yaml
+    # child path/to/microservice_a.yml
+    workflow:
+      rules:
+        - if: $CI_MERGE_REQUEST_ID
+
+    job1:
+      script: ...
+
+    job2:
+      script: ...
+    ```
+
+  - Alternatively, setting the rule per job. For example, to create only `job1` in
+    the context of merge request pipelines:
+
+    ```yaml
+    # child path/to/microservice_a.yml
+    job1:
+      script: ...
+      rules:
+        - if: $CI_MERGE_REQUEST_ID
+
+    job2:
+      script: ...
+    ```
+
 ## Limitations
 
 A parent pipeline can trigger many child pipelines, but a child pipeline cannot trigger
diff --git a/doc/user/application_security/container_scanning/index.md b/doc/user/application_security/container_scanning/index.md
index 8fc3ea4ee98..861c0e53103 100644
--- a/doc/user/application_security/container_scanning/index.md
+++ b/doc/user/application_security/container_scanning/index.md
@@ -176,7 +176,7 @@ using environment variables.
 | `CI_APPLICATION_TAG`           | Docker respository tag for the image to be scanned.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                | `$CI_COMMIT_SHA`                                                                                                |
 | `CLAIR_DB_IMAGE`               | The Docker image name and tag for the [Postgres server hosting the vulnerabilities definitions](https://hub.docker.com/r/arminc/clair-db). It can be useful to override this value with a specific version, for example, to provide a consistent set of vulnerabilities for integration testing purposes, or to refer to a locally hosted vulnerabilities database for an on-premise air-gapped installation.                                                                                                                                                                                                                                                                                                                                                                      | `arminc/clair-db:latest`                                                                                        |
 | `CLAIR_DB_IMAGE_TAG`           | (**DEPRECATED - use `CLAIR_DB_IMAGE` instead**) The Docker image tag for the [Postgres server hosting the vulnerabilities definitions](https://hub.docker.com/r/arminc/clair-db). It can be useful to override this value with a specific version, for example, to provide a consistent set of vulnerabilities for integration testing purposes.                                                                                                                                                                                                                                                                                                                                                                                                                                   | `latest`                                                                                                        |
-| `DOCKERFILE_PATH`              | The path to the `Dockerfile` to be used for generating remediations.  By default, the scanner will look for a file named `Dockerfile` in the root directory of the project, so this variable should only be configured if your `Dockerfile` is in a non-standard location, such as a subdirectory. See [Solutions for vulnerabilities](#solutions-for-vulnerabilities-auto-remediation) for more details.                                                                                                                                                                                                                                                                                                                                                                          | `Dockerfile`                                                                                                    |
+| `DOCKERFILE_PATH`              | The path to the `Dockerfile` to be used for generating remediations. By default, the scanner will look for a file named `Dockerfile` in the root directory of the project, so this variable should only be configured if your `Dockerfile` is in a non-standard location, such as a subdirectory. See [Solutions for vulnerabilities](#solutions-for-vulnerabilities-auto-remediation) for more details.                                                                                                                                                                                                                                                                                                                                                                          | `Dockerfile`                                                                                                    |
 
 ## Security Dashboard
 
@@ -352,7 +352,7 @@ the report JSON unless stated otherwise. Presence of optional fields depends on
 |------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
 | `version`                                            | Report syntax version used to generate this JSON.                                                                                                                                                                                                                                                                                                                                          |
 | `vulnerabilities`                                    | Array of vulnerability objects.                                                                                                                                                                                                                                                                                                                                                            |
-| `vulnerabilities[].category`                         | Where this vulnerability belongs (SAST, Container Scanning etc.). For Container Scanning, it will always be `container_scanning`.                                                                                                                                                                                                                                                          |
+| `vulnerabilities[].category`                         | Where this vulnerability belongs (for example, SAST or Container Scanning). For Container Scanning, it will always be `container_scanning`.                                                                                                                                                                                                                                                          |
 | `vulnerabilities[].message`                          | A short text that describes the vulnerability, it may include occurrence's specific information. Optional.                                                                                                                                                                                                                                                                                 |
 | `vulnerabilities[].description`                      | A long text that describes the vulnerability. Optional.                                                                                                                                                                                                                                                                                                                                    |
 | `vulnerabilities[].cve`                              | A fingerprint string value that represents a concrete occurrence of the vulnerability. It's used to determine whether two vulnerability occurrences are same or different. May not be 100% accurate. **This is NOT a [CVE](https://cve.mitre.org/)**.                                                                                                                                      |
@@ -388,7 +388,7 @@ the report JSON unless stated otherwise. Presence of optional fields depends on
 ### docker: Error response from daemon: failed to copy xattrs
 
 When the GitLab Runner uses the Docker executor and NFS is used
-(e.g., `/var/lib/docker` is on an NFS mount), Container Scanning might fail with
+(for example, `/var/lib/docker` is on an NFS mount), Container Scanning might fail with
 an error like the following:
 
 ```text
diff --git a/doc/user/group/issues_analytics/index.md b/doc/user/group/issues_analytics/index.md
index 6c710885b98..4477b9bb1e6 100644
--- a/doc/user/group/issues_analytics/index.md
+++ b/doc/user/group/issues_analytics/index.md
@@ -4,13 +4,14 @@ type: reference
 
 # Issues Analytics **(PREMIUM)**
 
-> [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/7478) in [GitLab Premium](https://about.gitlab.com/pricing/) 11.5.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/7478) in [GitLab Premium](https://about.gitlab.com/pricing/) 11.5.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/196561) in [GitLab Premium](https://about.gitlab.com/pricing/) 12.9 at the project level.
 
 Issues Analytics is a bar graph which illustrates the number of issues created each month.
 The default timespan is 13 months, which includes the current month, and the 12 months
 prior.
 
-To access the chart, navigate to a group's sidebar and select **Analytics > Issues Analytics**.
+To access the chart, navigate to your group or project sidebar and select **{chart}** **Analytics > Issues Analytics**.
 
 Hover over each bar to see the total number of issues.
 
diff --git a/lib/gitlab/background_migration/cleanup_optimistic_locking_nulls.rb b/lib/gitlab/background_migration/cleanup_optimistic_locking_nulls.rb
new file mode 100644
index 00000000000..3aa1ebb49f9
--- /dev/null
+++ b/lib/gitlab/background_migration/cleanup_optimistic_locking_nulls.rb
@@ -0,0 +1,32 @@
+# frozen_string_literal: true
+# rubocop:disable Style/Documentation
+
+module Gitlab
+  module BackgroundMigration
+    class CleanupOptimisticLockingNulls
+      QUERY_ITEM_SIZE = 1_000
+
+      # table - The name of the table the migration is performed for.
+      # start_id - The ID of the object to start at
+      # stop_id - The ID of the object to end at
+      def perform(start_id, stop_id, table)
+        model = define_model_for(table)
+
+        # After analysis done, a batch size of 1,000 items per query was found to be
+        # the most optimal. Discussion in https://gitlab.com/gitlab-org/gitlab/-/merge_requests/18418#note_282285336
+        (start_id..stop_id).each_slice(QUERY_ITEM_SIZE).each do |range|
+          model
+              .where(lock_version: nil)
+              .where(id: range)
+              .update_all(lock_version: 0)
+        end
+      end
+
+      def define_model_for(table)
+        Class.new(ActiveRecord::Base) do
+          self.table_name = table
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/database/migration_helpers.rb b/lib/gitlab/database/migration_helpers.rb
index 6317e034cfb..95a562ca1f3 100644
--- a/lib/gitlab/database/migration_helpers.rb
+++ b/lib/gitlab/database/migration_helpers.rb
@@ -1042,6 +1042,7 @@ into similar problems in the future (e.g. when new tables are created).
       # job_class_name - The background migration job class as a string
       # delay_interval - The duration between each job's scheduled time (must respond to `to_f`)
       # batch_size - The maximum number of rows per job
+      # other_arguments - Other arguments to send to the job
       #
       # Example:
       #
@@ -1059,7 +1060,7 @@ into similar problems in the future (e.g. when new tables are created).
       #         # do something
       #       end
       #     end
-      def queue_background_migration_jobs_by_range_at_intervals(model_class, job_class_name, delay_interval, batch_size: BACKGROUND_MIGRATION_BATCH_SIZE)
+      def queue_background_migration_jobs_by_range_at_intervals(model_class, job_class_name, delay_interval, batch_size: BACKGROUND_MIGRATION_BATCH_SIZE, other_arguments: [])
         raise "#{model_class} does not have an ID to use for batch ranges" unless model_class.column_names.include?('id')
 
         # To not overload the worker too much we enforce a minimum interval both
@@ -1074,7 +1075,7 @@ into similar problems in the future (e.g. when new tables are created).
           # `BackgroundMigrationWorker.bulk_perform_in` schedules all jobs for
           # the same time, which is not helpful in most cases where we wish to
           # spread the work over time.
-          migrate_in(delay_interval * index, job_class_name, [start_id, end_id])
+          migrate_in(delay_interval * index, job_class_name, [start_id, end_id] + other_arguments)
         end
       end
 
diff --git a/spec/features/projects/navbar_spec.rb b/spec/features/projects/navbar_spec.rb
index bcb05e1c718..4ab6b0ce506 100644
--- a/spec/features/projects/navbar_spec.rb
+++ b/spec/features/projects/navbar_spec.rb
@@ -3,102 +3,123 @@
 require 'spec_helper'
 
 describe 'Project navbar' do
-  it_behaves_like 'verified navigation bar' do
-    let(:user) { create(:user) }
-    let(:project) { create(:project, :repository) }
+  let(:user) { create(:user) }
+  let(:project) { create(:project, :repository) }
 
-    let(:structure) do
-      [
-        {
-          nav_item: _('Project overview'),
-          nav_sub_items: [
-            _('Details'),
-            _('Activity'),
-            _('Releases')
-          ]
-        },
-        {
-          nav_item: _('Repository'),
-          nav_sub_items: [
-            _('Files'),
-            _('Commits'),
-            _('Branches'),
-            _('Tags'),
-            _('Contributors'),
-            _('Graph'),
-            _('Compare'),
-            (_('Locked Files') if Gitlab.ee?)
-          ]
-        },
-        {
-          nav_item: _('Issues'),
-          nav_sub_items: [
-            _('List'),
-            _('Boards'),
-            _('Labels'),
-            _('Milestones')
-          ]
-        },
-        {
-          nav_item: _('Merge Requests'),
-          nav_sub_items: []
-        },
-        {
-          nav_item: _('CI / CD'),
-          nav_sub_items: [
-            _('Pipelines'),
-            _('Jobs'),
-            _('Artifacts'),
-            _('Schedules')
-          ]
-        },
-        {
-          nav_item: _('Operations'),
-          nav_sub_items: [
-            _('Metrics'),
-            _('Environments'),
-            _('Error Tracking'),
-            _('Serverless'),
-            _('Kubernetes')
-          ]
-        },
-        {
-          nav_item: _('Analytics'),
-          nav_sub_items: [
-            _('CI / CD Analytics'),
-            (_('Code Review') if Gitlab.ee?),
-            _('Repository Analytics'),
-            _('Value Stream Analytics')
-          ]
-        },
-        {
-          nav_item: _('Wiki'),
-          nav_sub_items: []
-        },
-        {
-          nav_item: _('Snippets'),
-          nav_sub_items: []
-        },
-        {
-          nav_item: _('Settings'),
-          nav_sub_items: [
-            _('General'),
-            _('Members'),
-            _('Integrations'),
-            _('Repository'),
-            _('CI / CD'),
-            _('Operations'),
-            (_('Audit Events') if Gitlab.ee?)
-          ].compact
-        }
+  let(:analytics_nav_item) do
+    {
+      nav_item: _('Analytics'),
+      nav_sub_items: [
+        _('CI / CD Analytics'),
+        (_('Code Review') if Gitlab.ee?),
+        _('Repository Analytics'),
+        _('Value Stream Analytics')
       ]
-    end
+    }
+  end
 
-    before do
-      project.add_maintainer(user)
-      sign_in(user)
+  let(:structure) do
+    [
+      {
+        nav_item: _('Project overview'),
+        nav_sub_items: [
+          _('Details'),
+          _('Activity'),
+          _('Releases')
+        ]
+      },
+      {
+        nav_item: _('Repository'),
+        nav_sub_items: [
+          _('Files'),
+          _('Commits'),
+          _('Branches'),
+          _('Tags'),
+          _('Contributors'),
+          _('Graph'),
+          _('Compare'),
+          (_('Locked Files') if Gitlab.ee?)
+        ]
+      },
+      {
+        nav_item: _('Issues'),
+        nav_sub_items: [
+          _('List'),
+          _('Boards'),
+          _('Labels'),
+          _('Milestones')
+        ]
+      },
+      {
+        nav_item: _('Merge Requests'),
+        nav_sub_items: []
+      },
+      {
+        nav_item: _('CI / CD'),
+        nav_sub_items: [
+          _('Pipelines'),
+          _('Jobs'),
+          _('Artifacts'),
+          _('Schedules')
+        ]
+      },
+      {
+        nav_item: _('Operations'),
+        nav_sub_items: [
+          _('Metrics'),
+          _('Environments'),
+          _('Error Tracking'),
+          _('Serverless'),
+          _('Kubernetes')
+        ]
+      },
+      analytics_nav_item,
+      {
+        nav_item: _('Wiki'),
+        nav_sub_items: []
+      },
+      {
+        nav_item: _('Snippets'),
+        nav_sub_items: []
+      },
+      {
+        nav_item: _('Settings'),
+        nav_sub_items: [
+          _('General'),
+          _('Members'),
+          _('Integrations'),
+          _('Repository'),
+          _('CI / CD'),
+          _('Operations'),
+          (_('Audit Events') if Gitlab.ee?)
+        ].compact
+      }
+    ]
+  end
+
+  before do
+    project.add_maintainer(user)
+    sign_in(user)
+  end
 
+  it_behaves_like 'verified navigation bar' do
+    before do
       visit project_path(project)
     end
   end
+
+  if Gitlab.ee?
+    context 'when issues analytics is available' do
+      before do
+        stub_licensed_features(issues_analytics: true)
+
+        analytics_nav_item[:nav_sub_items] << _('Issues Analytics')
+        analytics_nav_item[:nav_sub_items].sort!
+
+        visit project_path(project)
+      end
+
+      it_behaves_like 'verified navigation bar'
+    end
+  end
 end
diff --git a/spec/frontend/frequent_items/components/frequent_items_list_item_spec.js b/spec/frontend/frequent_items/components/frequent_items_list_item_spec.js
new file mode 100644
index 00000000000..925699f5623
--- /dev/null
+++ b/spec/frontend/frequent_items/components/frequent_items_list_item_spec.js
@@ -0,0 +1,103 @@
+import { shallowMount } from '@vue/test-utils';
+import { trimText } from 'helpers/text_helper';
+import frequentItemsListItemComponent from '~/frequent_items/components/frequent_items_list_item.vue';
+import mockData from '../mock_data'; // can also use 'mockGroup', but not useful to test here
+
+const mockProject = mockData();
+
+describe('FrequentItemsListItemComponent', () => {
+  let wrapper;
+
+  const findTitle = () => wrapper.find({ ref: 'frequentItemsItemTitle' });
+  const findAvatar = () => wrapper.find({ ref: 'frequentItemsItemAvatar' });
+  const findAllTitles = () => wrapper.findAll({ ref: 'frequentItemsItemTitle' });
+  const findNamespace = () => wrapper.find({ ref: 'frequentItemsItemNamespace' });
+  const findAllAnchors = () => wrapper.findAll('a');
+  const findAllNamespace = () => wrapper.findAll({ ref: 'frequentItemsItemNamespace' });
+  const findAvatarContainer = () => wrapper.findAll({ ref: 'frequentItemsItemAvatarContainer' });
+  const findAllMetadataContainers = () =>
+    wrapper.findAll({ ref: 'frequentItemsItemMetadataContainer' });
+
+  const createComponent = (props = {}) => {
+    wrapper = shallowMount(frequentItemsListItemComponent, {
+      propsData: {
+        itemId: mockProject.id,
+        itemName: mockProject.name,
+        namespace: mockProject.namespace,
+        webUrl: mockProject.webUrl,
+        avatarUrl: mockProject.avatarUrl,
+        ...props,
+      },
+    });
+  };
+
+  afterEach(() => {
+    wrapper.destroy();
+    wrapper = null;
+  });
+
+  describe('computed', () => {
+    describe('highlightedItemName', () => {
+      it('should enclose part of project name in <b> & </b> which matches with `matcher` prop', () => {
+        createComponent({ matcher: 'lab' });
+
+        expect(findTitle().element.innerHTML).toContain('<b>L</b><b>a</b><b>b</b>');
+      });
+
+      it('should return project name as it is if `matcher` is not available', () => {
+        createComponent({ matcher: null });
+
+        expect(trimText(findTitle().text())).toBe(mockProject.name);
+      });
+    });
+
+    describe('truncatedNamespace', () => {
+      it('should truncate project name from namespace string', () => {
+        createComponent({ namespace: 'platform / nokia-3310' });
+
+        expect(trimText(findNamespace().text())).toBe('platform');
+      });
+
+      it('should truncate namespace string from the middle if it includes more than two groups in path', () => {
+        createComponent({
+          namespace: 'platform / hardware / broadcom / Wifi Group / Mobile Chipset / nokia-3310',
+        });
+
+        expect(trimText(findNamespace().text())).toBe('platform / ... / Mobile Chipset');
+      });
+    });
+  });
+
+  describe('template', () => {
+    beforeEach(() => {
+      createComponent();
+    });
+
+    it('should render avatar if avatarUrl is present', () => {
+      wrapper.setProps({ avatarUrl: 'path/to/avatar.png' });
+
+      return wrapper.vm.$nextTick(() => {
+        expect(findAvatar().exists()).toBe(true);
+      });
+    });
+
+    it('should not render avatar if avatarUrl is not present', () => {
+      expect(findAvatar().exists()).toBe(false);
+    });
+
+    it('renders root element with the right classes', () => {
+      expect(wrapper.classes('frequent-items-list-item-container')).toBe(true);
+    });
+
+    it.each`
+      name                    | selector                     | expected
+      ${'anchor'}             | ${findAllAnchors}            | ${1}
+      ${'avatar container'}   | ${findAvatarContainer}       | ${1}
+      ${'metadata container'} | ${findAllMetadataContainers} | ${1}
+      ${'title'}              | ${findAllTitles}             | ${1}
+      ${'namespace'}          | ${findAllNamespace}          | ${1}
+    `('should render $expected $name', ({ selector, expected }) => {
+      expect(selector()).toHaveLength(expected);
+    });
+  });
+});
diff --git a/spec/frontend/frequent_items/mock_data.js b/spec/frontend/frequent_items/mock_data.js
new file mode 100644
index 00000000000..81f34053543
--- /dev/null
+++ b/spec/frontend/frequent_items/mock_data.js
@@ -0,0 +1,9 @@
+import { TEST_HOST } from 'helpers/test_constants';
+
+export default () => ({
+  id: 1,
+  name: 'GitLab Community Edition',
+  namespace: 'gitlab-org / gitlab-ce',
+  webUrl: `${TEST_HOST}/gitlab-org/gitlab-foss`,
+  avatarUrl: null,
+});
diff --git a/spec/javascripts/frequent_items/components/frequent_items_list_item_spec.js b/spec/javascripts/frequent_items/components/frequent_items_list_item_spec.js
deleted file mode 100644
index e3f05e89a2d..00000000000
--- a/spec/javascripts/frequent_items/components/frequent_items_list_item_spec.js
+++ /dev/null
@@ -1,94 +0,0 @@
-import { shallowMount, createLocalVue } from '@vue/test-utils';
-import { trimText } from 'spec/helpers/text_helper';
-import frequentItemsListItemComponent from '~/frequent_items/components/frequent_items_list_item.vue';
-import { mockProject } from '../mock_data'; // can also use 'mockGroup', but not useful to test here
-
-const localVue = createLocalVue();
-
-describe('FrequentItemsListItemComponent', () => {
-  let wrapper;
-
-  const createComponent = (props = {}) => {
-    wrapper = shallowMount(localVue.extend(frequentItemsListItemComponent), {
-      propsData: {
-        itemId: mockProject.id,
-        itemName: mockProject.name,
-        namespace: mockProject.namespace,
-        webUrl: mockProject.webUrl,
-        avatarUrl: mockProject.avatarUrl,
-        ...props,
-      },
-      localVue,
-    });
-  };
-
-  afterEach(() => {
-    wrapper.destroy();
-    wrapper = null;
-  });
-
-  describe('computed', () => {
-    describe('hasAvatar', () => {
-      it('should return `true` or `false` if whether avatar is present or not', () => {
-        createComponent({ avatarUrl: 'path/to/avatar.png' });
-
-        expect(wrapper.vm.hasAvatar).toBe(true);
-      });
-
-      it('should return `false` if avatar is not present', () => {
-        createComponent({ avatarUrl: null });
-
-        expect(wrapper.vm.hasAvatar).toBe(false);
-      });
-    });
-
-    describe('highlightedItemName', () => {
-      it('should enclose part of project name in <b> & </b> which matches with `matcher` prop', () => {
-        createComponent({ matcher: 'lab' });
-
-        expect(wrapper.find('.js-frequent-items-item-title').html()).toContain(
-          '<b>L</b><b>a</b><b>b</b>',
-        );
-      });
-
-      it('should return project name as it is if `matcher` is not available', () => {
-        createComponent({ matcher: null });
-
-        expect(trimText(wrapper.find('.js-frequent-items-item-title').text())).toBe(
-          mockProject.name,
-        );
-      });
-    });
-
-    describe('truncatedNamespace', () => {
-      it('should truncate project name from namespace string', () => {
-        createComponent({ namespace: 'platform / nokia-3310' });
-
-        expect(trimText(wrapper.find('.js-frequent-items-item-namespace').text())).toBe('platform');
-      });
-
-      it('should truncate namespace string from the middle if it includes more than two groups in path', () => {
-        createComponent({
-          namespace: 'platform / hardware / broadcom / Wifi Group / Mobile Chipset / nokia-3310',
-        });
-
-        expect(trimText(wrapper.find('.js-frequent-items-item-namespace').text())).toBe(
-          'platform / ... / Mobile Chipset',
-        );
-      });
-    });
-  });
-
-  describe('template', () => {
-    it('should render component element', () => {
-      createComponent();
-
-      expect(wrapper.classes()).toContain('frequent-items-list-item-container');
-      expect(wrapper.findAll('a').length).toBe(1);
-      expect(wrapper.findAll('.frequent-items-item-avatar-container').length).toBe(1);
-      expect(wrapper.findAll('.frequent-items-item-metadata-container').length).toBe(1);
-      expect(wrapper.findAll('.frequent-items-item-title').length).toBe(1);
-      expect(wrapper.findAll('.frequent-items-item-namespace').length).toBe(1);
-    });
-  });
-});
diff --git a/spec/lib/gitlab/database/migration_helpers_spec.rb b/spec/lib/gitlab/database/migration_helpers_spec.rb
index bb5475130cf..ce6e8c731e2 100644
--- a/spec/lib/gitlab/database/migration_helpers_spec.rb
+++ b/spec/lib/gitlab/database/migration_helpers_spec.rb
@@ -1332,6 +1332,15 @@ describe Gitlab::Database::MigrationHelpers do
           end
         end
       end
+
+      context 'with other_arguments option' do
+        it 'queues jobs correctly' do
+          model.queue_background_migration_jobs_by_range_at_intervals(User, 'FooJob', 10.minutes, other_arguments: [1, 2])
+
+          expect(BackgroundMigrationWorker.jobs[0]['args']).to eq(['FooJob', [id1, id3, 1, 2]])
+          expect(BackgroundMigrationWorker.jobs[0]['at']).to eq(10.minutes.from_now.to_f)
+        end
+      end
     end
 
     context "when the model doesn't have an ID column" do
diff --git a/spec/migrations/cleanup_optimistic_locking_nulls_spec.rb b/spec/migrations/cleanup_optimistic_locking_nulls_spec.rb
new file mode 100644
index 00000000000..bec8435b2f0
--- /dev/null
+++ b/spec/migrations/cleanup_optimistic_locking_nulls_spec.rb
@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20200128210353_cleanup_optimistic_locking_nulls')
+
+describe CleanupOptimisticLockingNulls, :migration do
+  TABLES = %w(epics merge_requests issues).freeze
+  TABLES.each do |table|
+    let(table.to_sym) { table(table.to_sym) }
+  end
+  let(:tables) { TABLES.map { |t| method(t.to_sym).call } }
+
+  let(:namespaces) { table(:namespaces) }
+  let(:projects) { table(:projects) }
+  let(:users) { table(:users)}
+
+  before do
+    namespaces.create!(id: 123, name: 'gitlab1', path: 'gitlab1')
+    projects.create!(id: 123, name: 'gitlab1', path: 'gitlab1', namespace_id: 123)
+    users.create!(id: 123, username: 'author', projects_limit: 1000)
+
+    # Create necessary rows
+    epics.create!(iid: 123, group_id: 123, author_id: 123, title: 'a', title_html: 'a')
+    merge_requests.create!(iid: 123, target_project_id: 123, source_project_id: 123, target_branch: 'master', source_branch: 'hmm', title: 'a', title_html: 'a')
+    issues.create!(iid: 123, project_id: 123, title: 'a', title_html: 'a')
+
+    # Nullify `lock_version` column for all rows
+    # Needs to be done with a SQL fragment, otherwise Rails will coerce it to 0
+    tables.each do |table|
+      table.update_all('lock_version = NULL')
+    end
+  end
+
+  it 'correctly migrates nullified lock_version column', :sidekiq_inline do
+    tables.each do |table|
+      expect(table.where(lock_version: nil).count).to eq(1)
+    end
+
+    tables.each do |table|
+      expect(table.where(lock_version: 0).count).to eq(0)
+    end
+
+    migrate!
+
+    tables.each do |table|
+      expect(table.where(lock_version: nil).count).to eq(0)
+    end
+
+    tables.each do |table|
+      expect(table.where(lock_version: 0).count).to eq(1)
+    end
+  end
+end