wp_fix_server_vars

			if ( isset( $_SERVER['PATH_INFO'] ) ) {
				if ( $_SERVER['PATH_INFO'] == $_SERVER['SCRIPT_NAME'] ) {
					$_SERVER['REQUEST_URI'] = $_SERVER['PATH_INFO'];
				} else {
					$_SERVER['REQUEST_URI'] = $_SERVER['SCRIPT_NAME'] . $_SERVER['PATH_INFO'];
				}
			}

			// Append the query string if it exists and isn't null.
			if ( ! empty( $_SERVER['QUERY_STRING'] ) ) {
				$_SERVER['REQUEST_URI'] .= '?' . $_SERVER['QUERY_STRING'];
			}
		}
	}

	// Fix for PHP as CGI hosts that set SCRIPT_FILENAME to something ending in php.cgi for all requests.
	if ( isset( $_SERVER['SCRIPT_FILENAME'] ) && ( strpos( $_SERVER['SCRIPT_FILENAME'], 'php.cgi' ) == strlen( $_SERVER['SCRIPT_FILENAME'] ) - 7 ) ) {
		$_SERVER['SCRIPT_FILENAME'] = $_SERVER['PATH_TRANSLATED'];
	}

	// Fix for Dreamhost and other PHP as CGI hosts.
	if ( strpos( $_SERVER['SCRIPT_NAME'], 'php.cgi' ) !== false ) {
		unset( $_SERVER['PATH_INFO'] );
	}

	// Fix empty PHP_SELF.
	$PHP_SELF = $_SERVER['PHP_SELF'];
	if ( empty( $PHP_SELF ) ) {
		$_SERVER['PHP_SELF'] = preg_replace( '/(\?.*)?$/', '', $_SERVER['REQUEST_URI'] );
		$PHP_SELF            = $_SERVER['PHP_SELF'];
	}
}

/**
 * Check for the required PHP version, and the MySQL extension or
 * a database drop-in.
 *
 * Dies if requirements are not met.
 *
 * @since 3.0.0
 * @access private
 *
 * @global string $required_php_version The required PHP version string.
 * @global string $wp_version           The WordPress version string.
 */
function wp_check_php_mysql_versions() {
	global $required_php_version, $wp_version;
	$php_version = phpversion();

	if ( version_compare( $required_php_version, $php_version, '>' ) ) {
		$protocol = wp_get_server_protocol();
		header( sprintf( '%s 500 Internal Server Error', $protocol ), true, 500 );
		header( 'Content-Type: text/html; charset=utf-8' );
		printf( 'Your server is running PHP version %1$s but WordPress %2$s requires at least %3$s.', $php_version, $wp_version, $required_php_version );
		exit( 1 );
	}

	if ( ! extension_loaded( 'mysql' ) && ! extension_loaded( 'mysqli' ) && ! extension_loaded( 'mysqlnd' ) && ! file_exists( WP_CONTENT_DIR . '/db.php' ) ) {