Fix issue importing members with owner access

changelogs/unreleased/fix-import-member-access.yml

+---
+title: Fix issue importing members with owner access
+merge_request: 28636
+author:
+type: fixed

doc/user/project/settings/import_export.md

@@ -23,6 +23,7 @@
 >    in the import side is required to map the users, based on email or username.
 >    Otherwise, a supplementary comment is left to mention the original author and
 >    the MRs, notes or issues will be owned by the importer.
+>  - Project members with owner access will get imported as maintainers.
 >  - Control project Import/Export with the [API](../../../api/project_import_export.md).
 >  - If an imported project contains merge requests originated from forks, 
 >    then new branches associated with such merge requests will be created 

lib/gitlab/import_export/members_mapper.rb

@@ -59,7 +59,11 @@ module Gitlab
       end
 
       def member_hash(member)
-        parsed_hash(member).merge('source_id' => @project.id, 'importing' => true)
+        parsed_hash(member).merge(
+          'source_id' => @project.id,
+          'importing' => true,
+          'access_level' => [member['access_level'], ProjectMember::MAINTAINER].min
+        )
       end
 
       def parsed_hash(member)

spec/lib/gitlab/import_export/members_mapper_spec.rb

@@ -73,6 +73,13 @@ describe Gitlab::ImportExport::MembersMapper do
       expect(user2.authorized_project?(project)).to be true
     end
 
+    it 'maps an owner as a maintainer' do
+      exported_members.first['access_level'] = ProjectMember::OWNER
+
+      expect(members_mapper.map[exported_user_id]).to eq(user2.id)
+      expect(ProjectMember.find_by_user_id(user2.id).access_level).to eq(ProjectMember::MAINTAINER)
+    end
+
     context 'user is not an admin' do
       let(:user) { create(:user) }