Messages - Add validation of users field before sending message - refs BT#19397

main/messages/new_message.php

@@ -183,6 +183,7 @@ function manageForm($default, $select_from_user_list = null, $sent_to = '', $tpl
                             'url' => api_get_path(WEB_AJAX_PATH).'message.ajax.php?a=find_users',
                         ]
                     );
+                    $form->addRule('users', get_lang('ThisFieldIsRequired'), 'required');
                 }
             } else {
                 $form->addElement('hidden', 'hidden_user', $default['users'][0], ['id' => 'hidden_user']);
@@ -451,10 +452,10 @@ if (!isset($_POST['compose'])) {
             if (isset($_POST['hidden_user'])) {
                 $default['users'] = [$_POST['hidden_user']];
             }
-            $social_right_content .= manageForm($default, null, null, $tpl);
+        } /*else {
-        } else {
             $social_right_content .= Display::return_message(get_lang('ErrorSendingMessage'), 'error');
-        }
+        }*/
+        $social_right_content .= manageForm($default, null, null, $tpl);
     }
 }