Also check if required fields are empty

includes/pages/guest_login.php

@@ -92,30 +92,22 @@ function guest_register()
     if ($request->hasPostData('submit')) {
         $valid = true;
 
-        if ($request->has('prename')) {
-            $preName = strip_request_item('prename');
-        } else {
+        if (!$request->has('prename') || empty($preName = strip_request_item('prename'))) {
             $valid = false;
             $msg .= error(__('Please enter your first name.'), true);
         }
 
-        if ($request->has('lastname')) {
-            $lastName = strip_request_item('lastname');
-        } else {
+        if (!$request->has('lastname') || empty($lastName = strip_request_item('lastname'))) {
             $valid = false;
             $msg .= error(__('Please enter your last name.'), true);
         }
 
-        if ($request->has('mobile')) {
-            $mobile = strip_request_item('mobile');
-
-            if (User::whereName($mobile)->count() > 0) {
-                $valid = false;
-                $msg .= error(__('This mobile number is already in use.'), true);
-            }
-        } else {
+        if (!$request->has('mobile') || empty($mobile = strip_request_item('mobile'))) {
             $valid = false;
             $msg .= error(__('Please enter your mobile number.'), true);
+        } else if (User::whereName($mobile)->count() > 0) {
+            $valid = false;
+            $msg .= error(__('This mobile number is already in use.'), true);
         }
 
         if ($request->has('mobile_consent')) {
@@ -314,6 +306,10 @@ function guest_register()
         $lastName = $form_data['last_name'];
     }
 
+    if (!$mobile && !empty($form_data['phone_number'])) {
+        $mobile = $form_data['phone_number'];
+    }
+
     return page_with_title(register_title(), [
         form_element('', __('By completing this form you\'re registering as a Chaos-Angel. This script will create you an account in the angel task scheduler.')),
         form_element('', entry_required() . ' = ' . __('Entry required!')),