Ensure query_constraints_list is empty if primary_key is nil

Author: nvasilevski

activerecord/test/cases/persistence_test.rb

@@ -1439,6 +1439,15 @@ def test_primary_key_stays_the_same
     assert_equal("id", ClothingItem.primary_key)
   end
 
+  def test_query_constraints_list_is_an_empty_array_if_primary_key_is_nil
+    klass = Class.new(ActiveRecord::Base) do
+      self.table_name = "developers_projects"
+    end
+
+    assert_nil klass.primary_key
+    assert_empty klass.query_constraints_list
+  end
+
   def test_query_constraints_uses_primary_key_by_default
     post = posts(:welcome)
     assert_uses_query_constraints_on_reload(post, "id")