squashed - refactor to cope with sub sub N relations probably using the sub_relations method recursively.

CHANGELOG

@@ -32,6 +32,31 @@ v 8.10.0 (unreleased)
   - Add basic system information like memory and disk usage to the admin panel
 
 v 8.9.5 (unreleased)
+  - Don't garbage collect commits that have related DB records like comments
+  - More descriptive message for git hooks and file locks
+  - Handle custom Git hook result in GitLab UI
+  - Allow '?', or '&' for label names
+  - Fix importer for GitHub Pull Requests when a branch was reused across Pull Requests
+  - Add date when user joined the team on the member page
+  - Fix 404 redirect after validation fails importing a GitLab project
+  - Added setting to set new users by default as external !4545 (Dravere)
+
+v 8.9.6
+  - Fix importing of events under notes for GitLab projects
+
+v 8.9.5
+  - Add more debug info to import/export and memory killer. !5108
+  - Fixed avatar alignment in new MR view. !5095
+  - Fix diff comments not showing up in activity feed. !5069
+  - Add index on both Award Emoji user and name. !5061
+  - Downgrade to Redis 3.2.2 due to massive memory leak with Sidekiq. !5056
+  - Re-enable import button when import process fails due to namespace already being taken. !5053
+  - Fix snippets comments not displayed. !5045
+  - Fix emoji paths in relative root configurations. !5027
+  - Fix issues importing events in Import/Export. !4987
+  - Fixed 'use shortcuts' button on docs. !4979
+  - Admin should be able to turn shared runners into specific ones. !4961
+  - Update RedCloth to 4.3.2 for CVE-2012-6684. !4929 (Takuya Noguchi)
   - Improve the request / withdraw access button. !4860
   - Fix assigning shared runners as admins. !4961
   - Show "locked" label for locked runners on runners admin. !4961

lib/gitlab/import_export/project_tree_restorer.rb

@@ -70,10 +70,19 @@ module Gitlab
       # Example:
       # +relation_key+ issues, loops through the list of *issues* and for each individual
       # issue, finds any subrelations such as notes, creates them and assign them back to the hash
+      #
+      # Recursively calls this method if the sub-relation is a hash containing more sub-relations
       def create_sub_relations(relation, tree_hash)
         relation_key = relation.keys.first.to_s
+        return if tree_hash[relation_key].blank?
+
         tree_hash[relation_key].each do |relation_item|
           relation.values.flatten.each do |sub_relation|
+            # We just use author to get the user ID, do not attempt to create an instance.
+            next if sub_relation == :author
+
+            create_sub_relations(sub_relation, relation_item) if sub_relation.is_a?(Hash)
+
             relation_hash, sub_relation = assign_relation_hash(relation_item, sub_relation)
             relation_item[sub_relation.to_s] = create_relation(sub_relation, relation_hash) unless relation_hash.blank?
           end

spec/lib/gitlab/import_export/project.json

@@ -4208,7 +4208,18 @@
             "name": "User 4"
           },
           "events": [
-
+            {
+              "id": 529,
+              "target_type": "Note",
+              "target_id": 2521,
+              "title": "test levels",
+              "data": null,
+              "project_id": 4,
+              "created_at": "2016-07-07T14:35:12.128Z",
+              "updated_at": "2016-07-07T14:35:12.128Z",
+              "action": 6,
+              "author_id": 1
+            }
           ]
         },
         {

spec/lib/gitlab/import_export/project_tree_restorer_spec.rb

@@ -25,11 +25,27 @@ describe Gitlab::ImportExport::ProjectTreeRestorer, services: true do
         expect(Ci::Pipeline.first.notes).not_to be_empty
       end
 
-      it 'restores the correct event' do
+      it 'restores the correct event with symbolised data' do
         restored_project_json
 
         expect(Event.where.not(data: nil).first.data[:ref]).not_to be_empty
       end
+
+      context 'event at forth level of the tree' do
+        let(:event) { Event.where(title: 'test levels').first }
+
+        before do
+          restored_project_json
+        end
+
+        it 'restores the event' do
+          expect(event).not_to be_nil
+        end
+
+        it 'event belongs to note, belongs to merge request, belongs to a project' do
+          expect(event.note.noteable.project).not_to be_nil
+        end
+      end
     end
   end
 end