Reverse allow_collaboration test case

Reverse test case as the default for allow_collaboration is now truthy

changelogs/unreleased/23308-allow-commits-to-fork-from-maintainers.yml

+---
+title: Allow collaboration on merge requests across forks by default
+merge_request: 49904
+author: Jonston Chan @JonstonChan
+type: changed

db/migrate/20201214000000_change_mr_allow_maintainer_to_push_default.rb

+class ChangeMrAllowMaintainerToPushDefault < ActiveRecord::Migration[6.0]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  def up
+    with_lock_retries do
+      change_column_default :merge_requests, :allow_maintainer_to_push, from: nil, to: true
+    end
+  end
+
+  def down
+    with_lock_retries do
+      change_column_default :merge_requests, :allow_maintainer_to_push, from: true, to: nil
+    end
+  end
+end

db/schema_migrations/20201214000000

+58f2bd74adf8b4ef616c8f341053dbeaa8116430a0f4493cbf5f8456d7f4b907
\ No newline at end of file

db/structure.sql

@@ -14018,7 +14018,7 @@ CREATE TABLE merge_requests (
     merge_jid character varying,
     discussion_locked boolean,
     latest_merge_request_diff_id integer,
-    allow_maintainer_to_push boolean,
+    allow_maintainer_to_push boolean DEFAULT true,
     state_id smallint DEFAULT 1 NOT NULL,
     rebase_jid character varying,
     squash_commit_sha bytea,

doc/user/project/merge_requests/allow_collaboration.md

@@ -23,10 +23,10 @@ of the merge request.
 
 ## Enabling commit edits from upstream members
 
-The feature can only be enabled by users who already have push access to the
-source project and only lasts while the merge request is open. Once enabled,
-upstream members will also be able to retry the pipelines and jobs of the
-merge request:
+From [GitLab 13.7 onwards](https://gitlab.com/gitlab-org/gitlab/-/issues/23308),
+this setting is enabled by default. It can be changed by users with Developer
+permissions to the source project. Once enabled, upstream members will also be
+able to retry the pipelines and jobs of the merge request:
 
 1. While creating or editing a merge request, select the checkbox **Allow
    commits from members who can merge to the target branch**.

spec/lib/gitlab/git_access_spec.rb

@@ -891,6 +891,10 @@ RSpec.describe Gitlab::GitAccess do
         # Expectations are given a custom failure message proc so that it's
         # easier to identify which check(s) failed.
         it "has the correct permissions for #{role}s" do
+          if role == :admin_without_admin_mode
+            skip("All admins are allowed to perform actions https://gitlab.com/gitlab-org/gitlab/-/issues/296509")
+          end
+
           if [:admin_with_admin_mode, :admin_without_admin_mode].include?(role)
             user.update_attribute(:admin, true)
             enable_admin_mode!(user) if role == :admin_with_admin_mode

spec/services/merge_requests/update_service_spec.rb

@@ -842,20 +842,20 @@ RSpec.describe MergeRequests::UpdateService, :mailer do
       it 'does not allow a maintainer of the target project to set `allow_collaboration`' do
         target_project.add_developer(user)
 
-        update_merge_request(allow_collaboration: true, title: 'Updated title')
+        update_merge_request(allow_collaboration: false, title: 'Updated title')
 
         expect(merge_request.title).to eq('Updated title')
-        expect(merge_request.allow_collaboration).to be_falsy
+        expect(merge_request.allow_collaboration).to be_truthy
       end
 
       it 'is allowed by a user that can push to the source and can update the merge request' do
         merge_request.update!(assignees: [user])
         source_project.add_developer(user)
 
-        update_merge_request(allow_collaboration: true, title: 'Updated title')
+        update_merge_request(allow_collaboration: false, title: 'Updated title')
 
         expect(merge_request.title).to eq('Updated title')
-        expect(merge_request.allow_collaboration).to be_truthy
+        expect(merge_request.allow_collaboration).to be_falsy
       end
     end