The testing system likes to assume that HTTP Auth is supported by the PHP environment. See this new feature () as one example; there is also a test that will not work without HTTP Auth: .
PHP only supports HTTP Authorization when coupled with Apache as a module - when running PHP via a CGI gateway (which is increasingly popular, offering more flexibility) the PHP_AUTH_* server variables are not available.
There is in fact a way to add support for HTTP authentication in PHP running as a CGI interface. It is a bit roundabout, but not dirty if done right, and it would fit well among the other environment clean-up Drupal does - eg. populating the HTTP_HOST, HTTP_REFERER and SERVER_PROTOCOL variables. On the Apache side, it is based on mod_rewrite, which Drupal already relies on.
I suggest that Drupal should implement this method in its .htaccess and bootstrap phase, adding support for HTTP authentication on environments where Apache and PHP are not coupled together.
Putting together a patch now.
FAILED: [[SimpleTest]]: [MySQL] Unable to apply patch auth_4.patch. Unable to apply patch. See the log in the details link for more information.
FAILED: [[SimpleTest]]: [MySQL] Unable to apply patch auth.patch. Unable to apply patch. See the log in the details link for more information.
PASSED: [[SimpleTest]]: [MySQL] 58,145 pass(es).
PASSED: [[SimpleTest]]: [MySQL] 57,758 pass(es).
PASSED: [[SimpleTest]]: [MySQL] 40,283 pass(es).