1 files changed, 11 insertions, 0 deletions
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index ddfcaaf986..d054dfa25a 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -14,6 +14,7 @@ require 'models/car'
 require 'models/engine'
 require 'models/tyre'
 require 'models/minivan'
+require 'models/aircraft'
 
 
 class RelationTest < ActiveRecord::TestCase
@@ -365,6 +366,16 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal({ 'salary' => 100_000 }, Developer.none.where(salary: 100_000).where_values_hash)
   end
 
+
+  def test_null_relation_count
+    ac = Aircraft.new
+    assert_equal Hash.new, ac.engines.group(:id).count
+    assert_equal        0, ac.engines.count
+    ac.save
+    assert_equal Hash.new, ac.engines.group(:id).count
+    assert_equal        0, ac.engines.count
+  end
+
   def test_joins_with_nil_argument
     assert_nothing_raised { DependentFirm.joins(nil).first }
   end