.htaccess RewriteRule with existing file and folder - apache

Question

My web structure looks like this:
public_html/
/images/
/user/
/userimage1.jpg
/userimage2.jpg
/userimage3.jpg
/icons/
/index.php
/user.php
...
I have 2 domains: example.com and images.example.com and I want to use a .htaccess RewriteRule that the images.example.com subdomain leads to the /images/-folder but also to use URLs without the file extension.
My .htaccess looks like this:
<IfModule mod_rewrite.c>
Options +FollowSymLinks +MultiViews
RewriteEngine on
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
RewriteCond %{HTTP_HOST} ^images\.example\.com$ [NC]
RewriteCond %{REQUEST_URI} !^/images/
RewriteRule ^(.*)$ /images/$1 [NC,L]
RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI} !-d
RewriteCond %{DOCUMENT_ROOT}%{REQUEST_URI}\.php -f
RewriteRule ^(.*)$ $1.php [L]
</IfModule>
Now, https://example.com/user/ works fine, but when I try to open https://images.example.com/user/userimage1.jpg it says that %{REQUEST_URI} is /images/redirect:/images/user.php/userimage1.jpg
Unfortunately, both, the domain and the subdomain have to be installed with public_html as the root folder.
How do I have to adept my .htaccess file so that both URLs, https://example.com/user/ and https://images.example.com/user/userimage1.jpg work fine?

Answer 1

You have a conflict with MultiViews (which you've enabled at the top). The fact that "https://example.com/user/ works fine" (with a trailing slash) is because of MultiViews, not because of your mod_rewrite directives. (The mod_rewrite directives as written would only "work" with /user - no trailing slash.)
When you request https://images.example.com/user/userimage1.jpg, MultiViews triggers an internal subrequest for /user.php/userimage1.jpg (/user.php with additional path-info /userimage1.jpg), but mod_rewrite has also tried to rewrite the request (an internal "redirect") - hence the seemingly malformed rewrite.
Generally, you need to avoid using MultiViews with mod_rewrite rewrites - a common cause of conflict.
Try the following instead:
Options +FollowSymLinks -MultiViews
RewriteEngine on
RewriteCond %{HTTPS} off
RewriteRule (.*) https://%{HTTP_HOST}%{REQUEST_URI} [R=301,L]
# Rewrite images subdomain
RewriteCond %{HTTP_HOST} ^images\.example\.com$ [NC]
RewriteCond %{REQUEST_URI} !^/images/
RewriteRule ^(.*)$ /images/$1 [L]
# Append .php file extensions
RewriteCond %{DOCUMENT_ROOT}/$1 !-d
RewriteCond %{DOCUMENT_ROOT}/$1\.php -f
RewriteRule ^(.*)/$ $1.php [L]
Note that I've included the trailing slash in the RewriteRule pattern and taken this out of the capturing subpattern - this is assuming that the trailing slash is mandatory on your URLs (as in your example).
You don't need the <IfModule> wrapper unless mod_rewrite really is optional? (It's not.)