mod_rewrite causing extra slash - apache

Question

I'm trying to simply remove .php from the filenames on URLs. I'm implementing the solution from this StackOverflow answer so my VirtualHost looks like this,
# domain: example.com
# public: /var/www/html/example.com/public_html/
<Directory /var/www/html/example.com/public_html>
Options +FollowSymLinks
AllowOverride All
DirectoryIndex index.html index.htm index.php
</Directory>
<VirtualHost *:80>
ServerName example.com
Redirect / https://example.com/
</VirtualHost>
<VirtualHost *:443>
# Admin details
ServerAdmin vanguard#example.com
ServerName example.com
ServerAlias www.example.com
SSLEngine on
SSLCertificateFile /etc/letsencrypt/live/example.com/fullchain.pem
SSLCertificateKeyFile /etc/letsencrypt/live/example.com/privkey.pem
#Index File
DirectoryIndex index.html index.php
DocumentRoot /var/www/html/example.com/public_html
#Log Details
LogLevel warn
ErrorLog /var/www/html/example.com/log/error.log
CustomLog /var/www/html/example.com/log/access.log combined
RewriteEngine On
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule !.*\.php$ %{REQUEST_FILENAME}.php [L]
</VirtualHost>
Going to https://example.com resolves just fine, but if I try to go to https://example.com/examplefile it rewrites it to https://example.com//examplefile/

Answer 1

RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule !.*\.php$ %{REQUEST_FILENAME}.php [L]
In a virtual host context this RewriteCond directive will never match because at the time the directive is processed the request has not yet been mapped to the file system, so REQUEST_FILENAME simply contains the URL-path (as opposed to the absolute filesystem path), which is the same as REQUEST_URI.
(This wouldn't work in .htaccess either, but for a different reason. In .htaccess you can't rewrite to an absolute filesystem path, so whilst the RewriteCond should match, the RewriteRule is likely to trigger a 403 Forbidden error.)
To fix this in a server/virtual host context, you can modify these directives to use a URL-based look-ahead:
RewriteCond %{LA-U:REQUEST_FILENAME}.php -f
RewriteRule !\.php$ %{LA-U:REQUEST_FILENAME}.php [L]
However, neither your original directives nor this correction explains the double slash you are seeing in your example. Either an erroneously cached response or your web application?