// component of the path in this space, converting
		// \\.\unc\a\b\..\c into \\.\unc\a\c.
		return uncLen(path, len(`\\.\UNC\`))

	case pathHasPrefixFold(path, `\\.`) ||
		pathHasPrefixFold(path, `\\?`) || pathHasPrefixFold(path, `\??`):
		// Path starts with \\.\, and is a Local Device path; or
		// path starts with \\?\ or \??\ and is a Root Local Device path.
		//
		// We treat the next component after the \\.\ prefix as