Header Content-length may cause problem

I found this line in the 4.6.3 common.inc on line 295.

Apache with mod_security enabled can trigger 403 errors with a content-length: 0 header sent. (for whatever reason)

This patch will only append the Content-Length header if we have content.

--- /home/gregm/drupal-4.7.2/includes/common.inc        2006-05-15 16:53:26.000000000 -0400
+++ www/localhost/htdocs/includes/common.inc    2006-07-12 08:25:06.000000000 -0400
@@ -399,9 +399,10 @@
     // We don't add the port to prevent from breaking rewrite rules checking
     // the host that do not take into account the port number.
     'Host' => "Host: $host",
-    'User-Agent' => 'User-Agent: Drupal (+http://drupal.org/)',
-    'Content-Length' => 'Content-Length: '. strlen($data)
-  );
+    'User-Agent' => 'User-Agent: Drupal (+http://drupal.org/)');
+    if (!empty($data)) {
+       $defaults['Content-Length'] = 'Content-Length:' . strlen($data);
+    }

   foreach ($headers as $header => $value) {
     $defaults[$header] = $header .': '. $value;

Must create a patch for 4.6.9
Checked the current HEAD and the bug is there too.

Following the advice by dlr and Centove here are the patches for CVS, 4.7 and 4.6

Anyway, this must be discussed further because these would be patches to solve both IIS and Apache bugs, as it seems.

Please post each patch separately and unarchived.

4.6.9

4.7.3

HEAD (2006-08-29)

I don't quite understand why we need this patch. Drupal has been reported to work on IIS just fine. I don't think we have business supporting broken servers.

http://www.ngssoftware.com/papers/iisrconfig.pdf

Note the Content-Length header is required even though there is no content and hence the length
is 0.

http://www.mail-archive.com/squid-users@squid-cache.org/msg40113.html

If you can, sending Content-Length is always best.