Update full-text search index when moving issues

When moving issues, we do several updates to the new issue within an
outer transaction. This caused `saved_changes` to return only the
changes of the latest update even if more changes were committed.

This meant `#update_search_data!` wasn't run even though we saved the
title and description of the issue.

app/models/concerns/pg_full_text_searchable.rb

@@ -80,6 +80,15 @@ def pg_full_text_searchable(columns:)
         pg_full_text_searchable_columns[column[:name]] = column[:weight]
       end
 
+      # When multiple updates are done in a transaction, `saved_changes` will only report the latest save
+      # and we may miss an update to the searchable columns.
+      # As a workaround, we set a dirty flag here and update the search data in `after_save_commit`.
+      after_save do
+        next unless pg_full_text_searchable_columns.keys.any? { |f| saved_changes.has_key?(f) }
+
+        @update_pg_full_text_search_data = true
+      end
+
       # We update this outside the transaction because this could raise an error if the resulting tsvector
       # is too long. When that happens, we still persist the create / update but the model will not have a
       # search data record. This is fine in most cases because this is a very rare occurrence and only happens
@@ -87,9 +96,8 @@ def pg_full_text_searchable(columns:)
       #
       # We also do not want to use a subtransaction here due to: https://gitlab.com/groups/gitlab-org/-/epics/6540
       after_save_commit do
-        next unless pg_full_text_searchable_columns.keys.any? { |f| saved_changes.has_key?(f) }
-
-        update_search_data!
+        update_search_data! if @update_pg_full_text_search_data
+        @update_pg_full_text_search_data = nil
       end
     end
 

spec/models/concerns/pg_full_text_searchable_spec.rb

@@ -54,12 +54,23 @@ def self.name
     end
 
     context 'when specified columns are not changed' do
-      it 'does not enqueue worker' do
+      it 'does not call update_search_data!' do
         expect(model).not_to receive(:update_search_data!)
 
         model.update!(description: 'A new description')
       end
     end
+
+    context 'when model is updated twice within a transaction' do
+      it 'calls update_search_data!' do
+        expect(model).to receive(:update_search_data!)
+
+        model.transaction do
+          model.update!(title: 'A new title')
+          model.update!(updated_at: Time.current)
+        end
+      end
+    end
   end
 
   describe '.pg_full_text_search' do