Apache / PHP / .htaccess routing filename to filename.php - php

Question

I'm trying to debug a php site and I've got a routing problem that I can't figure out.
It's a custom built site and most of the requests are routed via index.php
The problem I am having is that on the live server (Linux / Apache):
http://www.sitename.com/cart is routed through index.php as it should be.
but on my test server (osx / apache):
http://www.sitename.com/cart goes straight to http://www.sitename.com/cart.php without being routed through index.php
I assume it's something to do with the .htaccess file (below) but I can't figure out what. Also the .htaccess file is the same on both servers so I don't understand why it's working differently, any help much appreciated.
AddType application/x-httpd-php .html
Options +FollowSymLinks
RewriteEngine on
RewriteCond %{SERVER_PORT} ^443$
RewriteRule ^robots.txt$ robots_ssl.txt
RewriteCond %{REQUEST_fileNAME} !-f
RewriteRule ^([^.]+)\.s?html$ /index.php?q=$1 [L,QSA]
RewriteRule ^([^.]+)\.s?htm$ /index.php?q=$1 [L,QSA]
RewriteRule ^([^.]+)\.s?xml$ /index.php?q=$1 [L,QSA]
RewriteRule ^([^.]+)\.s?asp$ /index.php?q=$1 [L,QSA]
RewriteRule ^([^.]+)\.s?aspx$ /index.php?q=$1 [L,QSA]
RewriteRule ^robots.txt$ /index.php?q=$1 [L,QSA]
RewriteRule ^([^.]+)$ /index.php?q=$1 [L,QSA]
RewriteRule ^admin/.*$ - [PT]
#php_flag display_errors off
php_value default_charset ISO-8859-1
php_flag magic_quotes_gpc on
php_flag magic_quotes_runtime off
The virtual host file is as follows:
<VirtualHost *:80>
DocumentRoot "/Users/jim/Sites/sitename.com/public_html"
ServerName sitename.com
ServerAlias www.sitename.com
<directory "/Users/jim/Sites/sitename.com/public_html/">
Options Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
AllowOverride All
Order allow,deny
Allow from all
</directory>
</VirtualHost>

Answer 1

This is happening because of this line in your vhost config:
Options Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI MultiViews
Not sure why you need Multiviews to be set to "on" but it's part of mod_negotiation and processes the request before mod_rewrite does. It takes requests like /cart and decides whether there's a fuzzy match against an existing resource. It sees /cart.php and assumes that's what you want and serves up the request before mod_rewrite even gets a chance to do anything. You can turn it off by adding a - in front:
Options Indexes Includes FollowSymLinks SymLinksifOwnerMatch ExecCGI -MultiViews
You can also do this via the htaccess file's Options directive:
Options +FollowSymLinks -MultiViews