GroupController: Properly handle 404's when handling group members

refs #8826

application/controllers/GroupController.php

@@ -232,10 +232,6 @@ class GroupController extends AuthBackendController
         $groupName = $this->params->getRequired('group');
         $backend = $this->getUserGroupBackend($this->params->getRequired('backend'), 'Icinga\Data\Extensible');
 
-        if ($backend->select()->where('group_name', $groupName)->count() === 0) {
-            $this->httpNotFound(sprintf($this->translate('Group "%s" not found'), $groupName));
-        }
-
         $form = new AddMemberForm();
         $form->setDataSource($this->fetchUsers())
             ->setBackend($backend)
@@ -243,8 +239,13 @@ class GroupController extends AuthBackendController
             ->setRedirectUrl(
                 Url::fromPath('group/show', array('backend' => $backend->getName(), 'group' => $groupName))
             )
-            ->setUidDisabled()
+            ->setUidDisabled();
-            ->handleRequest();
+
+        try {
+            $form->handleRequest();
+        } catch (NotFoundError $_) {
+            $this->httpNotFound(sprintf($this->translate('Group "%s" not found'), $groupName));
+        }
 
         $this->view->form = $form;
         $this->render('form');
@@ -260,10 +261,6 @@ class GroupController extends AuthBackendController
         $groupName = $this->params->getRequired('group');
         $backend = $this->getUserGroupBackend($this->params->getRequired('backend'), 'Icinga\Data\Reducible');
 
-        if ($backend->select()->where('group_name', $groupName)->count() === 0) {
-            $this->httpNotFound(sprintf($this->translate('Group "%s" not found'), $groupName));
-        }
-
         $form = new Form(array(
             'onSuccess' => function ($form) use ($groupName, $backend) {
                 foreach ($form->getValue('user_name') as $userName) {
@@ -280,6 +277,8 @@ class GroupController extends AuthBackendController
                             $userName,
                             $groupName
                         ));
+                    } catch (NotFoundError $e) {
+                        throw $e;
                     } catch (Exception $e) {
                         Notification::error($e->getMessage());
                     }
@@ -297,7 +296,12 @@ class GroupController extends AuthBackendController
         $form->setSubmitLabel('btn_submit'); // Required to ensure that isSubmitted() is called
         $form->addElement('hidden', 'user_name', array('required' => true, 'isArray' => true));
         $form->addElement('hidden', 'redirect');
-        $form->handleRequest();
+
+        try {
+            $form->handleRequest();
+        } catch (NotFoundError $_) {
+            $this->httpNotFound(sprintf($this->translate('Group "%s" not found'), $groupName));
+        }
     }
 
     /**

application/forms/Config/UserGroup/AddMemberForm.php

@@ -7,6 +7,7 @@ use Exception;
 use Icinga\Data\Extensible;
 use Icinga\Data\Filter\Filter;
 use Icinga\Data\Selectable;
+use Icinga\Exception\NotFoundError;
 use Icinga\Web\Form;
 use Icinga\Web\Notification;
 
@@ -155,6 +156,8 @@ class AddMemberForm extends Form
                         'user_name'     => $userName
                     )
                 );
+            } catch (NotFoundError $e) {
+                throw $e; // Trigger 404, the group name is initially accessed as GET parameter
             } catch (Exception $e) {
                 Notification::error(sprintf(
                     $this->translate('Failed to add "%s" as group member for "%s"'),