Merge pull request rails#53706 from fatkodima/fix-where-with-cpk-nil-association

Fix finding by nil composite primary key association

Author: kamipo

activerecord/lib/active_record/relation/predicate_builder/association_query_value.rb

@@ -59,6 +59,8 @@ def polymorphic_clause?
         def convert_to_id(value)
           if primary_key.is_a?(Array)
             primary_key.map do |attribute|
+              next nil if value.nil?
+
               if attribute == "id"
                 value.id_value
               else

activerecord/test/cases/relation/where_test.rb

@@ -149,6 +149,15 @@ def test_with_tuple_syntax_and_large_values_list
       end
     end
 
+    def test_where_with_nil_cpk_association
+      order = Cpk::Order.create!(id: [1, 2])
+      book = order.books.create!(id: [3, 4])
+      assert_includes Cpk::Book.where(order: order), book
+
+      book.update!(order: nil)
+      assert_includes Cpk::Book.where(order: nil), book
+    end
+
     def test_belongs_to_shallow_where
       author = Author.new
       author.id = 1