Fix various Warning messages

app/models/postn/Postn.php

@@ -601,7 +601,8 @@ class Postn extends Model
     public function getComments()
     {
         $pd = new \Modl\PostnDAO;
-        return $pd->getComments($this);
+        $comments = $pd->getComments($this);
+        return $comments ? $comments : [];
     }
 
     public function countComments()

app/widgets/CommunitiesServers/CommunitiesServers.php

@@ -46,9 +46,10 @@ class CommunitiesServers extends \Movim\Widget\Base
     function prepareCommunities()
     {
         $id = new \Modl\InfoDAO;
+        $servers = $id->getCommunitiesServers();
 
         $view = $this->tpl();
-        $view->assign('servers', $id->getCommunitiesServers() ?? []);
+        $view->assign('servers', $servers ? $servers : []);
 
         return $view->draw('_communitiesservers', true);
     }

app/widgets/ContactData/ContactData.php

@@ -33,11 +33,13 @@ class ContactData extends \Movim\Widget\Base
             $view->assign('message', $m[0]);
         }
 
+        $subscriptions = $id->getSharedItems($jid);
+
         $view->assign('mood', getMood());
         $view->assign('clienttype', getClientTypes());
         $view->assign('contact', $cd->get($jid));
         $view->assign('contactr', $contactr);
-        $view->assign('subscriptions', $id->getSharedItems($jid) ?? []);
+        $view->assign('subscriptions', $subscriptions ? $subscriptions : []);
 
         if(isset($contactr)) {
             if($contactr->value != null) {

app/widgets/Login/Login.php

@@ -69,19 +69,23 @@ class Login extends \Movim\Widget\Base
 
         $this->view->assign('invitation', null);
 
-        if($this->get('i') && Validator::length(8)->validate($this->get('i'))) {
+        if ($this->get('i')
+        && Validator::length(8)->validate($this->get('i'))) {
             $invitation = \Modl\Invite::get($this->get('i'));
-            $this->view->assign('invitation', $invitation);
 
-            $cd = new \Modl\ContactDAO;
-            $this->view->assign('contact', $cd->get($invitation->jid));
+            if($invitation) {
+                $this->view->assign('invitation', $invitation);
+
+                $cd = new \Modl\ContactDAO;
+                $this->view->assign('contact', $cd->get($invitation->jid));
+            }
         }
 
         $this->view->assign('pop', $pop-2);
         $this->view->assign('connected', (int)requestURL('http://localhost:1560/started/', 2));
         $this->view->assign('error', $this->prepareError());
 
-        if(isset($_SERVER['PHP_AUTH_USER'])
+        if (isset($_SERVER['PHP_AUTH_USER'])
         && isset($_SERVER['PHP_AUTH_PW'])
         && Validator::email()->length(6, 40)->validate($_SERVER['HTTP_EMAIL'])) {
             list($username, $host) = explode('@', $_SERVER['HTTP_EMAIL']);