Just in case you thought having a path starting with c:/ or C:/ was the same... let me tell you how wrong you are.

Setting up my new computer

I've been migrating all my local websites to a new computer, with a fresh install of WAMPServer (yes, I'm not a big docker & co fan). I used to configure my website with a nice little snippet to automatically create all my vhosts like this:

#
# Dynamic Virtual Host Definitions
#
<IfModule mod_vhost_alias.c>
    # example.com              -->  /var/www/vhosts/example.com/www
    # www.example.com          -->  /var/www/vhosts/example.com/www
    # a.www.example.com        -->  /var/www/vhosts/example.com/a.www
    # shop.example.com        -->  /var/www/vhosts/example.com/shop
    <VirtualHost *:80>
      ServerName sub.domain
      ServerAlias *.*.*
      VirtualDocumentRoot "D:/www/%-2.0.%-1.0/%-3"
    </VirtualHost>
    <VirtualHost *:80>
      ServerName bare.domain
      ServerAlias *.*
      VirtualDocumentRoot "D:/www/%-2.0.%-1.0/www"
    </VirtualHost>
    <VirtualHost *:80>
      ServerName sub.domain
      ServerAlias *.*.*
      VirtualDocumentRoot "D:/www/%-2.0.%-1.0/%-3"
      SSLCertificateFile "D:/wamp64/bin/apache/apache2.4.51/conf/key/localhost/server.crt"
      SSLCertificateKeyFile "D:/wamp64/bin/apache/apache2.4.51/conf/key/localhost/server.key"
      SSLEngine on
    </VirtualHost>
    <VirtualHost *:80>
      ServerName bare.domain
      ServerAlias *.*
      VirtualDocumentRoot "D:/www/%-2.0.%-1.0/www"
      SSLCertificateFile "D:/wamp64/bin/apache/apache2.4.51/conf/key/localhost/server.crt"
      SSLCertificateKeyFile "D:/wamp64/bin/apache/apache2.4.51/conf/key/localhost/server.key"
      SSLEngine on
    </VirtualHost>
    <VirtualHost *:8000>
      ServerName sub.domain
      ServerAlias *.*.*
      VirtualDocumentRoot "D:/www/%-2.0.%-1.0/%-3/public"
    </VirtualHost>
    <VirtualHost *:8000>
      ServerName sub.domain
      ServerAlias *.*.*
      VirtualDocumentRoot "D:/www/%-2.0.%-1.0/%-3/public"
      SSLCertificateFile "D:/wamp64/bin/apache/apache2.4.51/conf/key/localhost/server.crt"
      SSLCertificateKeyFile "D:/wamp64/bin/apache/apache2.4.51/conf/key/localhost/server.key"
      SSLEngine on
    </VirtualHost>
    <VirtualHost *:8000>
      ServerName bare.domain
      ServerAlias *.*
      VirtualDocumentRoot "D:/www/%-2.0.%-1.0/www/public"
    </VirtualHost>
    <VirtualHost *:8000>
      ServerName bare.domain
      ServerAlias *.*
      VirtualDocumentRoot "D:/www/%-2.0.%-1.0/www/public"
      SSLCertificateFile "D:/wamp64/bin/apache/apache2.4.51/conf/key/localhost/server.crt"
      SSLCertificateKeyFile "D:/wamp64/bin/apache/apache2.4.51/conf/key/localhost/server.key"
      SSLEngine on
    </VirtualHost>
</IfModule>

This allows me to map mywebsite.local to D:/www/mywebsite.local/ (and to the "public" folder if I'm using port 8000). This worked quite well, until my recent migration.

Seems working, but mod rewrite fails

In the snippet above, I was using a lowercase "d" instead. All the websites work, but as soon as you get a mod rewrite rule, you get an infinite loop resulting in an error 500. I scratched my head for a while, tried an older version of apache... nothing worked.

Until... I tried to rename the lowercase "d:/" to a "D:/"... and it worked! Why? I don't know ! Probably some odd bug that take case into account when interpreting mod rewrite rules.