Use assert_equal instead of assert in uploaded file test.

actionpack/test/dispatch/uploaded_file_test.rb

@@ -16,7 +16,7 @@ def test_original_filename
     if "ruby".encoding_aware?
       def test_filename_should_be_in_utf_8
         uf = Http::UploadedFile.new(:filename => 'foo', :tempfile => Object.new)
-        assert "UTF-8", uf.original_filename.encoding.to_s
+        assert_equal "UTF-8", uf.original_filename.encoding.to_s
       end
     end