Problem:
The current check is intended to match DOS device paths starting with
`\\?` or `\\.` but will match any path starting with `?` or `.`,
including relative paths such as `.\`.
This is because the leading slashes are removed before the comparison.
Solution:
Changes the check to include the path's prefix, assuring the path has
the correct amount of separators for a DOS device path.
4a5062cda6