php not interpreted ONLY in shibboleth-protected directory - php

Question

I have searched everywhere for an answer to this, without success.
I have PHP installed on my OSX web server. When I access myserver.com/test.php everything works perfectly.
However, I have a subdirectory protected by mod_shib and shibd called /shibboleth/
When I put the exact same test.php file into /shibboleth/ it is served back to the browser rather than interpreted. I have messed with a million combinations of AddType and AddHandler; I've checked that I'm using
Here is the relevant part of my httpd.conf file:
<VirtualHost *:443>
SSLEngine on
SSLCipherSuite ALL:!ADH:!EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP:+eNULL
ServerName jeesty.homeip.net
DocumentRoot "/Library/WebServer/Safe"
DirectoryIndex index.html index.php
DefaultType text/plain
AddType application/x-httpd-php .php
AddHandler application/x-httpd-php .php
<Directory "/Library/WebServer/Safe/">
DirectoryIndex index.html index.php
Options Indexes FollowSymLinks MultiViews
AllowOverride None
Order allow,deny
Allow from all
php_admin_flag engine on
</Directory>
<Location /shibboleth/>
SetHandler shib
AuthType shibboleth
ShibRequestSetting requireSession 1
Require valid-user
php_admin_flag engine on
</Location>
</VirtualHost>

Answer 1

If the directory is literally /shibboleth, then it's outside the document root of /Library/WebServer, and as such won't inherit a bunch of important configuration directives declared elsewhere in httpd.conf.