For the user of your application it can often be difficult to determine what the relative path is relative to. All DCli errors that contain a path call truepath so that the path is absolute and normalised, this gives your users the best chance of correctly identifying the file or path that caused the problem.
You should also normalised any path that a user enters. Using '..' to bypass security checks is a common hacking trick.
If you need to compare to paths you need to both canonicalize your path. As Windows paths are case-insensitive the canonicalize operations returns a all lowercase version of the path which ensures to equivalent paths will return true when a string comparison is performed. The call to canonicalize will also normalize the path.
The only safe way to compare two paths it to compare two absolute paths that have been canonicalized: