Rewrite rules cause some URLs to fail

[wpmuguru]

MU Trac Ticket: ​http://trac.mu.wordpress.org/ticket/215

The following lines are not necessary with a vhost install and $base = '/' :

RewriteRule  ^([_0-9a-zA-Z-]+/)?(wp-.*) $2 [L]
RewriteRule  ^([_0-9a-zA-Z-]+/)?(.*\.php)$ $2 [L]

They could conduct to an infinite rewrite loop and lead the web server to a 500 error.

I have rules for nginx that fix this. I have to convert to apache and test.

(In [12884]) change wp- rewrite more specific rewrite rule, see #11994

For problems with the fix we can use #12136.