Bug in option "attach existing images"

In image_attach_form_alter($form_id, &$form), line:
$existing = variable_get('existingImageAttachDisabled', 1);
should be
$existing = variable_get('image_attach_existing', 1);
(In current download version is line#69)

There is no "existingImageAttachDisabled" variable.

Without this patch that option is unusable.