request_uri() broken under thttpd [IIS]

Update to request_uri() method definition from bootstrap.inc for HTTP servers (such as IIS or the above mentioned thttpd) that do not provide the REQUEST_URI header and do provide the information through QUERY_STRING.

function request_uri() {
/*
** Since request_uri() is only available on Apache, we generate
** equivalent using other environment vars.
*/

if (isset($_SERVER["REQUEST_URI"])) {
$uri = $_SERVER["REQUEST_URI"];
}
else if (isset($_SERVER["QUERY_STRING"])) {
$uri = $_SERVER["QUERY_STRING"];
}
else {
$uri = $_SERVER["PHP_SELF"] ."?". $_SERVER["argv"][0];
}

return check_url($uri);
}

request_uri() is also broken under Xitami: neither _SERVER["REQUEST_URI"] nor _SERVER["argv"] are valued. However, the standard CGI environment variables _SERVER["SCRIPT_NAME"] and _SERVER["QUERY_STRING"] are valued. (These are probably the lowest-common-denominator variables for obtaining the URI.)

The attached patch adds support for servers that provide standard CGI environment variables. Note that the test must be for the presence of SCRIPT_NAME since QUERY_STRING is not always valued.

Based on the original poster's remarks, I doubt that this patch will work for thttpd, since its REQUEST_URI seems to be broken. This could be remedied by putting the new test first.