mod_rewrite not appending queries - mod-rewrite

Question

I have a site where I am trying to rewrite search/ks3/7/example-topic to search.php?ks=ks3&year=7&topic=example-topic
I am using apache mod_rewrite and my .htaccess looks like this:
RewriteEngine On
RewriteBase /
RewriteRule ^search/(a-zA-Z0-9+)/(a-zA-Z0-9+)/(a-zA-Z0-9-+) search.php?ks=$1&year=$2&topic=$3 [R=301,L]
However, when I browse to search/ks3/7/example my php $_GET['ks'], $_GET['topic'] and $_GET['year'] contain no data.
My apache error log shows errors in the PHP "undefined index ks" etc.
My rewrite log (which is set to a verbosity of 9) shows:
192.168.0.171 - - [08/Jan/2012:13:11:46 +0000] [192.168.0.10/sid#7ff3cc9b7460][rid#7ff3c65f90a0/initial] (3) [perdir /data/shared/chemistry/] add path info postfix: /data/shared/chemistry/search.php -> /data/shared/chemistry/search.php/ks3/7/example-topic
192.168.0.171 - - [08/Jan/2012:13:11:46 +0000] [192.168.0.10/sid#7ff3cc9b7460][rid#7ff3c65f90a0/initial] (3) [perdir /data/shared/chemistry/] strip per-dir prefix: /data/shared/chemistry/search.php/ks3/7/example-topic -> search.php/ks3/7/example-topic
192.168.0.171 - - [08/Jan/2012:13:11:46 +0000] [192.168.0.10/sid#7ff3cc9b7460][rid#7ff3c65f90a0/initial] (3) [perdir /data/shared/chemistry/] applying pattern '^search/(a-zA-Z0-9+)/(a-zA-Z0-9+)/(a-zA-Z0-9-+)$' to uri 'search.php/ks3/7/example-topic'
192.168.0.171 - - [08/Jan/2012:13:11:46 +0000] [192.168.0.10/sid#7ff3cc9b7460][rid#7ff3c65f90a0/initial] (1) [perdir /data/shared/chemistry/] pass through /data/shared/chemistry/search.php
192.168.0.171 - - [08/Jan/2012:13:11:46 +0000] [192.168.0.10/sid#7ff3cc9b7460][rid#7ff3c65f00a0/subreq] (1) [perdir /data/shared/chemistry/] pass through /data/shared/chemistry/ks3
and my apache virtual hosts file looks like this
<VirtualHost *:80>
ServerAdmin powerj96#hotmail.co.uk
DocumentRoot /data/shared/chemistry
<Directory /data/shared/chemistry/>
Options Indexes FollowSymLinks MultiViews
AllowOverride All
</Directory>
<Directory />
Options Indexes FollowSymLinks MultiViews
AllowOverride All
Order allow,deny
allow from all
</Directory>
</VirtualHost>
Mod_Rewrite is definitely working. I have tried the rule:
RewriteRule ^google http://www.google.com [R=301,L]
and this works.
I also run 4 other virtual hosts on the server, 3 of which are just websites and 1 is transmission's web interface.
I am running Ubuntu Server 11.11
EDIT:
I think the problem may be to do with running reverse proxy alongside this. for example, if reverse proxy is changing 192.168.0.10:81 (address of my server and port 81 vhost) to transmission/web then the fact that transmission is running at 192.168.0.10/transmission/web, which is both a vhost and a subdirectory of the site which is running at 192.168.0.10/ (the one in question on this post), may be causing conflicts in the rewrite module. Do you have any ideas of a solution to this if you think it may be the problem.
EDIT:
This is the complete log for everything that happens when I click the link search/ks3/7/example-topic
(1) [perdir /data/shared/chemistry/] pass through /data/shared/chemistry/search.php
(3) [perdir /data/shared/chemistry/] add path info postfix: /data/shared/chemistry/search.php -> /data/shared/chemistry/search.php/ks3/7/example-topic
(3) [perdir /data/shared/chemistry/] strip per-dir prefix: /data/shared/chemistry/search.php/ks3/7/example-topic -> search.php/ks3/7/example-topic
(3) [perdir /data/shared/chemistry/] applying pattern '^search/([^/]+)/([^/]+)/([^/]+)' to uri 'search.php/ks3/7/example-topic'
(1) [perdir /data/shared/chemistry/] pass through /data/shared/chemistry/search.php
(1) [perdir /data/shared/chemistry/] pass through /data/shared/chemistry/ks3
EDIT:
I have realised the source of the problem after looking at that log file. For some reason apache is rewriting search/ks3/7/example-topic to search.php/ks3/7/example-topic before it applies my rewrite, therefore search/ks3/7/example-topic doesn't satisfy the
^search/([^/]+)/([^/]+)/([^/]+)
rule. I have changed the rule to
^search.php/([^/]+)/([^/]+)/([^/]+)
and this works.
Do you have any idea of how to stop apache rewriting search/ks3/7/example-topic to search.php/ks3/7/example-topic ?
It is working now, after removing the QSA, NC and R=301 options.

Answer 1

Your rewritelog doesn't tell much. Remove IP information at the beginning (who cares?). And add the beginning of rewrite (= tell us what is the uri that will be rewritten): take a look at the first line of the following log.
Here's an example of what should be more helpful:
(2) init rewrite engine with requested uri /robots.txt
(3) applying pattern '(.*)setup.php' to uri '/robots.txt'
(3) applying pattern '(.*)admin(.*)' to uri '/robots.txt'
(3) applying pattern '(.*)' to uri '/robots.txt'
(4) RewriteCond: input='www.papdevis.com' pattern='!(papdevis)' [NC] => not-matched
(3) applying pattern '(.*)' to uri '/robots.txt'
(4) RewriteCond: input='www.papdevis.com' pattern='(.*)\.(com|net|org|eu)' [NC] => matched
(2) rewrite '/robots.txt' -> 'http://www.papdevis.fr/robots.txt'
(2) explicitly forcing redirect with http://www.papdevis.fr/robots.txt
(1) escaping http://www.papdevis.fr/robots.txt for redirect
(1) redirect to http://www.papdevis.fr/robots.txt [REDIRECT/301]
(2) init rewrite engine with requested uri /
(3) applying pattern '(.*)setup.php' to uri '/'
(3) applying pattern '(.*)admin(.*)' to uri '/'
(3) applying pattern '(.*)' to uri '/'
(4) RewriteCond: input='www.papdevis.com' pattern='!(papdevis)' [NC] => not-matched
(3) applying pattern '(.*)' to uri '/'
(4) RewriteCond: input='www.papdevis.com' pattern='(.*)\.(com|net|org|eu)' [NC] => matched
(2) rewrite '/' -> 'http://www.papdevis.fr/'
(2) explicitly forcing redirect with http://www.papdevis.fr/
(1) escaping http://www.papdevis.fr/ for redirect
(1) redirect to http://www.papdevis.fr/ [REDIRECT/301]
Rewrite from:
search/ks3/7/example-topic
to
search.php?ks=ks3&year=7&topic=example-topic
And your .htaccess file looks like this:
RewriteEngine On
RewriteBase /
RewriteRule ^search/(a-zA-Z0-9+)/(a-zA-Z0-9+)/(a-zA-Z0-9-+) \
search.php?ks=$1&year=$2&topic=$3 [R=301,L]
It will never work... try this:
RewriteEngine On
RewriteBase /
RewriteRule ^search/([a-zA-Z0-9]+)/([a-zA-Z0-9]+)/([a-zA-Z0-9-]+) \
search.php?ks=$1&year=$2&topic=$3 [QSA,NC,R=301,L]
... or maybe how about taking everything but the slash? This may look like that:
RewriteEngine On
RewriteBase /
RewriteRule ^search/([^/]+)/([^/]+)/([^/]+) \
search.php?ks=$1&year=$2&topic=$3 [QSA,NC,R=301,L]
Please tell me if this works.
Two hints:
If you're not in a hosted environment (= if it's your own server and you can modify the virtual hosts, not only the .htaccess files), try to use the RewriteLog directive: it helps you to track down such problems:
# Trace:
# (!) file gets big quickly, remove in prod environments:
RewriteLog "/web/logs/mywebsite.rewrite.log"
RewriteLogLevel 9
RewriteEngine On
My favorite tool to check for regexp:
http://www.quanetic.com/Regex (don't forget to choose ereg(POSIX) instead of preg(PCRE)!)