[BoomBoomBap]

Looks like I got this working with Hair Guy's code.
Here's what Im using for 3.4.10

# new login mod
$mysite_pattern = '~^(http://'.$xcart_http_host.'|https://'.$xcart_https_host.')~';
                if($login_type=="C" && !func_is_cart_empty($cart)) {
                        if (preg_match('/\/cart\.php\?mode=(auth|checkout)/', $_SERVER['HTTP_REFERER'])) {
                                # go to next step in checkout
                                func_header_location("../$redirect/cart.php?mode=checkout");
                        } elseif (preg_match($mysite_pattern, $_SERVER['HTTP_REFERER'])) {
                                # go back to where we were before login
                                func_header_location(" ".$_SERVER['HTTP_REFERER']);
                        } else {
                                func_header_location("../$redirect/cart.php");
                        }
                } elseif ( ($config["General"]["default_pwd"]=="Y") and (count($default_accounts)>0) and $admin_safe_mode==false) {
                        echo"<SCRIPT language='JavaScript'>
                        alert('Default passwords for one or more administrator/provider accounts are not changed. We recommend you to change default passwords for security reasons. The default X-cart accounts$default_accounts_string!');   
                        self.location='$to_url';
                        </SCRIPT>If you see this message it means that your browser doesn't support Javascript or it is disabled. Please enable JavaScript in your browser settings for proper X-Cart functionality.";
			x_session_save();
			exit;
                }
                else {
                        if (preg_match($mysite_pattern, $_SERVER['HTTP_REFERER'])) {
                                # go back to where we were before login
                                func_header_location(" ".$_SERVER['HTTP_REFERER']);
                        } else {
                                func_header_location("../$redirect/home.php");
                        }
                } 
	} 
# here ends new login mod