Fix left join query for LFS Objects

Join should include `file_type` along with `file_id`, otherwise we may
be joining with the wrong data.

ee/app/models/geo/fdw/lfs_object.rb

@@ -56,7 +56,10 @@ module Geo
           join_statement =
             arel_table
               .join(file_registry_table, Arel::Nodes::OuterJoin)
-              .on(arel_table[:id].eq(file_registry_table[:file_id]))
+              .on(
+                arel_table[:id].eq(file_registry_table[:file_id])
+                  .and(file_registry_table[:file_type].eq(:lfs))
+              )
 
           joins(join_statement.join_sources)
         end

ee/changelogs/unreleased/32696-geo-lfs-not-being-synced.yml

+---
+title: 'Geo: LFS not being synced'
+merge_request: 17633
+author:
+type: fixed

ee/spec/models/geo/fdw/lfs_object_spec.rb

@@ -7,4 +7,19 @@ RSpec.describe Geo::Fdw::LfsObject, :geo, type: :model do
     it { is_expected.to have_many(:lfs_objects_projects).class_name('Geo::Fdw::LfsObjectsProject') }
     it { is_expected.to have_many(:projects).class_name('Geo::Fdw::Project').through(:lfs_objects_projects) }
   end
+
+  describe '.missing_file_registry', :geo_fdw do
+    subject { described_class.missing_file_registry }
+
+    it 'returns lfs objects that doesnt have a corresponding file registry entry' do
+      lfs_objects = create_list(:lfs_object, 2)
+
+      # simulate existing registry entries with the same +id+, but different +file_type+
+      lfs_objects.each do |lfs|
+        create(:geo_file_registry, file_id: lfs.id)
+      end
+
+      expect(subject).to match_ids(lfs_objects)
+    end
+  end
 end