What's going on with my mod_rewrite?

I have a simple mod_rewrite system set up on my site which basically converts

http://site.com/file -> http://site.com/file.php

Here's the .htaccess file

Options -MultiViews
RewriteEngine On

RewriteCond %{HTTP_HOST} ^www.site.com
RewriteRule ^(.*)$ http://site.com/$1 [R=301]

RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^([a-z]+)/?$ http://site.com/$1.php [L]

This was working for a long time and then a couple of days ago I realized that while the RewriteRule was working, it was actually changing my URL in the status bar.

For instance, it would redirect /photos to /photos.php, but it would also change t开发者_开发百科he URL to show the .php. This has never happened before and I'm not sure what happened to trigger the change.

Any ideas?

The first rewrite rule needs the [L] flag. From the mod_rewrite documentation for the [R] flag:

You will almost always want to use [R] in conjunction with [L] (that is, use [R,L]) because on its own, the [R] flag prepends http://thishost[:thisport] to the URI, but then passes this on to the next rule in the ruleset, which can often result in 'Invalid URI in request' warnings.

In this case, you don't get a warning, but appending the ".php" extension happens before issuing the redirect rather than when the second, redirected request comes in.

Also, remove the scheme and domain name from the substitution in the second rewrite rule. A full URL can cause an implicit redirect. From the documentation for RewriteRule:

The Substitution of a rewrite rule is the string that replaces the original URL-path that was matched by Pattern. The Substitution may be a:

[...]

Absolute URL

If an absolute URL is specified, mod_rewrite checks to see whether the hostname matches the current host. If it does, the scheme and hostname are stripped out and the resulting path is treated as a URL-path. Otherwise, an external redirect is performed for the given URL. To force an external redirect back to the current host, see the [R] flag below.