I've got a scenario involving two domains:

1. WordPress site hosted on domain1.com
2. domain2.co.uk, simply redirecting users to domain1 via mod_rewrite

This rule applies irrespective of whether www. is specified or not. (It's eventually removed from the URL, I'm a no-WWW fan.)

There's nothing on domain2.co.uk at all except for an .htaccess with some mod_rewrite rules. However, I want to be able to allow users to be redirected to the correct article URI even if they specify the "wrong" URL (i.e., a 301 redirect preserving the stuff after the first forward slash).

I'm currently achieving this with this ruleset:

RewriteCond %{HTTP_HOST} ^((www\.)?[^\.]+)\.domain2\.co\.uk [NC,OR]
RewriteCond %{HTTP_HOST} ^domain2\.co\.uk [NC]
RewriteRule ^(.*)$ http://domain1.com/$1 [R=301,L]

This works but is uglier than I want it to be. I'm not a mod_rewrite zen master, but from what I can tell the top rule should match irrespective of whether www. is specified... But it doesn't. In order to catch www-less requests, I need the second RewriteCond.

From the rewrite log, with just the first RewriteCond:

[domain2.co.uk/sid#e200498][rid#e670168/initial] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] strip per-dir prefix: /home/devnull/domains/domain2.co.uk/public_html/ -> 
[domain2.co.uk/sid#e200498][rid#e670168/initial] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] applying pattern '^(.*)$' to uri ''
[domain2.co.uk/sid#e200498][rid#e670168/initial] (4) [perdir /home/devnull/domains/domain2.co.uk/public_html/] RewriteCond: input='domain2.co.uk' pattern='^((www\.)|[^\.]+)\.domain2\.co\.uk' [NC] => not-matched
[domain2.co.uk/sid#e200498][rid#e670168/initial] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/
[domain2.co.uk/sid#e200498][rid#e653868/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.html
[domain2.co.uk/sid#e200498][rid#e65f8b8/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.htm
[domain2.co.uk/sid#e200498][rid#e653868/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.shtml
[domain2.co.uk/sid#e200498][rid#e65f8b8/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.php
[domain2.co.uk/sid#e200498][rid#e653868/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.php5
[domain2.co.uk/sid#e200498][rid#e666c98/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.php4
[domain2.co.uk/sid#e200498][rid#e65f8b8/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.php3
[domain2.co.uk/sid#e200498][rid#e653868/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.phtml
[domain2.co.uk/sid#e200498][rid#e65f8b8/subreq] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/index.cgi
[domain2.co.uk/sid#e200498][rid#e66c370/initial/redir#1] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] strip per-dir prefix: /home/devnull/domains/domain2.co.uk/public_html/403.shtml -> 403.shtml
[domain2.co.uk/sid#e200498][rid#e66c370/initial/redir#1] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] applying pattern '^(.*)$' to uri '403.shtml'
[domain2.co.uk/sid#e200498][rid#e66c370/initial/redir#1] (4) [perdir /home/devnull/domains/domain2.co.uk/public_html/] RewriteCond: input='domain2.co.uk' pattern='^((www\.)|[^\.]+)\.domain2\.co\.uk' [NC] => not-matched
[domain2.co.uk/sid#e200498][rid#e66c370/initial/redir#1] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/403.shtml
[domain2.co.uk/sid#e200498][rid#e668ca8/initial] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] strip per-dir prefix: /home/devnull/domains/domain2.co.uk/public_html/favicon.ico -> favicon.ico
[domain2.co.uk/sid#e200498][rid#e668ca8/initial] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] applying pattern '^(.*)$' to uri 'favicon.ico'
[domain2.co.uk/sid#e200498][rid#e668ca8/initial] (4) [perdir /home/devnull/domains/domain2.co.uk/public_html/] RewriteCond: input='domain2.co.uk' pattern='^((www\.)|[^\.]+)\.domain2\.co\.uk' [NC] => not-matched
[domain2.co.uk/sid#e200498][rid#e668ca8/initial] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/favicon.ico
[domain2.co.uk/sid#e200498][rid#f160b40/initial/redir#1] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] strip per-dir prefix: /home/devnull/domains/domain2.co.uk/public_html/404.shtml -> 404.shtml
[domain2.co.uk/sid#e200498][rid#f160b40/initial/redir#1] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] applying pattern '^(.*)$' to uri '404.shtml'
[domain2.co.uk/sid#e200498][rid#f160b40/initial/redir#1] (4) [perdir /home/devnull/domains/domain2.co.uk/public_html/] RewriteCond: input='domain2.co.uk' pattern='^((www\.)|[^\.]+)\.domain2\.co\.uk' [NC] => not-matched
[domain2.co.uk/sid#e200498][rid#f160b40/initial/redir#1] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] pass through /home/devnull/domains/domain2.co.uk/public_html/404.shtml

However with the second RewriteCond added, the rule works, and the logs show this:

[domain2.co.uk/sid#e200498][rid#e65fe58/initial] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] strip per-dir prefix: /home/devnull/domains/domain2.co.uk/public_html/ -> 
[domain2.co.uk/sid#e200498][rid#e65fe58/initial] (3) [perdir /home/devnull/domains/domain2.co.uk/public_html/] applying pattern '^(.*)$' to uri ''
[domain2.co.uk/sid#e200498][rid#e65fe58/initial] (4) [perdir /home/devnull/domains/domain2.co.uk/public_html/] RewriteCond: input='domain2.co.uk' pattern='^((www\.)?[^\.]+)\.domain2\.co\.uk' [NC] => not-matched
[domain2.co.uk/sid#e200498][rid#e65fe58/initial] (4) [perdir /home/devnull/domains/domain2.co.uk/public_html/] RewriteCond: input='domain2.co.uk' pattern='^domain2\.co\.uk' [NC] => matched
[domain2.co.uk/sid#e200498][rid#e65fe58/initial] (2) [perdir /home/devnull/domains/domain2.co.uk/public_html/] rewrite '' -> 'http://domain1.com/'
[domain2.co.uk/sid#e200498][rid#e65fe58/initial] (2) [perdir /home/devnull/domains/domain2.co.uk/public_html/] explicitly forcing redirect with http://domain1.com/
[domain2.co.uk/sid#e200498][rid#e65fe58/initial] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] escaping http://domain1.com/ for redirect
[domain2.co.uk/sid#e200498][rid#e65fe58/initial] (1) [perdir /home/devnull/domains/domain2.co.uk/public_html/] redirect to http://domain1.com/ [REDIRECT/301]

Can anybody help me figure out why it just won't work with the one rule? I feel like I'm missing the bleeding obvious, and while the second RewriteCond is a valid workaround, it's a kludge and that annoys me. ;-) All help appreciated...