Move where with blank conditions test to the correct where tests file

This test does not belong to has many associations test.

activerecord/test/cases/associations/has_many_associations_test.rb

@@ -298,12 +298,6 @@ def test_finding_array_compatibility
     assert_equal 2, Firm.order(:id).find{|f| f.id > 0}.clients.length
   end
 
-  def test_find_with_blank_conditions
-    [[], {}, nil, ""].each do |blank|
-      assert_equal 2, Firm.all.merge!(:order => "id").first.clients.where(blank).to_a.size
-    end
-  end
-
   def test_find_many_with_merged_options
     assert_equal 1, companies(:first_firm).limited_clients.size
     assert_equal 1, companies(:first_firm).limited_clients.to_a.size

activerecord/test/cases/relation/where_test.rb

@@ -85,5 +85,11 @@ def test_where_with_table_name_and_empty_hash
     def test_where_with_empty_hash_and_no_foreign_key
       assert_equal 0, Edge.where(:sink => {}).count
     end
+
+    def test_where_with_blank_conditions
+      [[], {}, nil, ""].each do |blank|
+        assert_equal 4, Edge.where(blank).order("sink_id").to_a.size
+      end
+    end
   end
 end