From the changelog:
Changes with Apache 1.3.17
*) Normalize the Netware path names to close a potential security
hole in comparing paths when the adminstrator specifies both
sys:foo and sys:/foo formats in the same httpd.conf file.
[Brad Nicholes]
*) Fix an unlikely segfault provided a zero length string in the
translate_userdir() call on win32/os2, and accept backslashes
in the UserDir directive on those platforms [William Rowe]