Really, it is best
not to edit
http.conf directly under MacOS X, so you can side-step this issue altogether. Notice the last line of Apple's
http.conf file:
Include /private/etc/httpd/users
That's intended to load http.conf customizations for individual users on your Mac. What it does, effectively, is append
every file in the directory
/private/etc/httpd/users/, in alphabetical order, to your /etc/httpd/httpd.conf file. So if you place a file containing
only the customizations you would otherwise make to /etc/httpd/httpd.conf in the directory
/private/etc/httpd/users/, your customizations will always be in effect
without ever editing your /etc/httpd/httpd.conf file. Slick, eh? This also saves you from having to re-edit this file if Apple should change it during a system update (folks here on this list have been complaining about this recently, and it is so easily avoided!)
Important safety tip: Every file in
/private/etc/httpd/users/ is appended to your /etc/httpd/httpd.conf file, even files with suffixes like ".bak", so keep your backup files in another directory, else they are likely to override the changes you're making in your primary file (e.g.
my.httpd.conf.bak would load
after my.httpd.conf, which might undo the edits you've made and send you off chasing your tail for hours while trying to figure out why the changes you're making don't seem to work properly -- of course i was never caught by this snare!

).