[development] Loading configuration using 'SERVER_NAME' as opposed to 'HTTP_HOST'

[Adam Cooper]

Hello all,

It's a (very) long time since I posted to this list. So please excuse  
me if I'm breaking etiquette. I'm attempting to set up a development  
environment that suits my way of working. Using a VMware virtual  
machine (that is as close a replica to my VPS as possible) I've set up  
an apache instance and am adding virtual hosts to it as I go. Up until  
now I've had no issue bring across my current sites. They all are  
single sites and so have been set up in the 'default' configuration. I  
can add an entry to my host machines hosts file (say 'sitename.dev')  
and everything works great.

The problem now is that I have come across one of my multisite  
configurations. I figured I could just set the virtual host  
configuration to have ServerName as my site name (sitename) and then  
ServerAlias in the name I would be accessing it as (sitename.dev).  
Setting UseCanonicalName to 'on' would let me access the site as I  
would expect.

Except, despite this setting SERVER_NAME to the value I expect  
(sitename) my drupal configuration refuses to load. I took a look in  
the bootstrap file and found that the configuration directory is  
loaded from HTTP_HOST.

TL;DR.

So my question is this, why does drupal load it's configuration using  
HTTP_HOST as opposed to SERVER_NAME? Surely SERVER_NAME would allow  
more flexibility and more direct control? Would a patch changing this  
have any chance of being looked at?

Thanks
Adam