id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc
22798,"Invalid URLs not giving 404 with ""Default"" permalink settings",vanchuck,,"'''Steps to reproduce:'''
 - Set up Wordpress with the default .htaccess
 - Select the ""Default"" option under Permalink Settings
 - Enter an invalid URL eg 'http://blogroot.com/garlbeflax.abc'

'''Expected Behaviour:'''
 - 404 page is displayed

'''Observed Behaviour:'''
 - No 404 page is ever shown, no matter what the request string is
 - Instead, Wordpress behaves as if no path was requested, eg displaying the homepage/posts lists.
 - If requested url has any of the standard params in it, those params ARE executed, eg http://blogroot.com/foo?paged=2 would properly show the 2nd page of the posts.

'''Suspected cause:'''

In line 620 of wp-includes/class-wp.php (in WP->parse_request), there is a conditional which means the only time the request can be marked as a 404 error is if the array of rewrite rules is NOT empty:
{{{
        $rewrite = $wp_rewrite->wp_rewrite_rules();

        if ( ! empty($rewrite) ) {
           ...
}}}

If the ""Default"" permalink is selected, and no other rewrite rules are set up elsewhere (for reasons I didn't investigate, adding a add_rewrite_rule to the theme didn't affect anything), then the $rewrite array IS empty and the request can not be checked to see if it's a 404. Therefore, execution of the request continues as if no path info were submitted.

This prevents the showing of the theme's 404 page, and can get a website flagged as spam/exploitative in Google's index.

'''Workaround:'''

Define a permalink redirect (eg pick one of the options other than Default). 

Server info:
{{{
Apache/2.2.16 (Debian) (w/ mod_rewrite)
PHP Version 5.3.3-7+squeeze3 (mod_php5)
}}}

.htaccess contents:
{{{
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
}}}",enhancement,new,normal,Awaiting Review,Rewrite Rules,3.4.2,normal,,,knut@…