$base_root is wrong behind an SSL accelerator

Thanks for the research and detailed background information, ghoti. In order for this patch to be 'committable', we'll want to add some comments to the code (and rework the code so the flow is slightly more readable). Without some extra information in the code, I'm afraid we'd not be able to understand it one or two years down the road. Thanks.

Minor code style issue - comments have to break at column 80, yours goes a little over.

As it seems this is a hot topic, I recently tried to apply this patch to my Drupal 5.7 and Drupal 6.1 sites, with some interesting results:

I am using Apache 2.0 to serve drupal.silverhammer.cc (Drupal 5), drupal6.silverhammer.cc (Drupal 6), www.silverhammer.cc (Drupal 5), and some other sites. I am providing SSL support through Pound 2.4.1.

My pound.cfg:

ListenHTTPS
    Address 69.36.166.244
        Port 443
        Cert "/etc/ssl/cert.pem"
    HeadRemove "X-Forwarded-Proto"
    AddHeader "X-Forwarded-Proto: https"
End

Service
    Backend
            Address 69.36.166.244
                Port 80
        End
End

... with the Header lines added per suggestion from http://mongrel.rubyforge.org/wiki/Pound .

Before applying patch line to $base_root:
http://www.silverhammer.cc/user => http://www.silverhammer.cc/user/1
BUT...
https://www.silverhammer.cc/user => https://www.silverhammer.ccuser/1 (Host not found)
Similarly with http://drupal6.silverhammer.cc

After applying patch line to $base_root:
https://drupal6.silverhammer.cc/user => https://drupal6.silverhammer.cc/user/1
BUT... with Drupal 5....
https://www.silverhammer.cc/user => https://www.silverhammer.ccuser/1 (Host not found)
still.

So, Drupal 5 should be recognizing this header just the same... is there a new rewrite functionality found in Drupal 6 that can be ported over to 5?

Repeatable results anyone?

For anyone running into this issue, here's what needs to be added to settings.php in Drupal 6 to avoid this problem (based on patch provided by Ghoti in #8)

Testing and working with AWS Elastic Load Balancer

/******************************************************************************
 * Force server to use https:// path if SSL is handled at load balancer       *
 ******************************************************************************/
if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') {
  // We're running HTTPS natively in the web server.
  $base_root = 'https';
}
elseif (isset($_SERVER['HTTP_X_FORWARDED_PROTO'])) {
  // We're behind a proxy that talks to the web server via HTTP.
  $base_root = $_SERVER['HTTP_X_FORWARDED_PROTO'];
}
else {
  // There's no HTTPS spoor -- we must be running HTTP.
  $base_root = 'http';
}

$base_url = $base_root .= '://'. $_SERVER['HTTP_HOST'];

// $_SERVER['SCRIPT_NAME'] can, in contrast to $_SERVER['PHP_SELF'], not
// be modified by a visitor.
if ($dir = trim(dirname($_SERVER['SCRIPT_NAME']), '\,/')) {
  $base_path = "/$dir";
  $base_url .= $base_path;
  $base_path .= '/';
}
else {
  $base_path = '/';
}