Avoid clear flash messages for plugin templates on regions - refs BT#10376 #TMI

main/inc/lib/plugin.lib.php

@@ -387,7 +387,7 @@ class AppPlugin
                             if (!empty($plugin_tpl)) {
                                 //$template_plugin_file = api_get_path(SYS_PLUGIN_PATH)."$plugin_name/$plugin_tpl"; //for smarty
                                 $template_plugin_file = "$plugin_name/$plugin_tpl"; // for twig
-                                $template->display($template_plugin_file);
+                                $template->display($template_plugin_file, false);
                             }
                         }
                     }

main/inc/lib/template.lib.php

@@ -1118,12 +1118,18 @@ class Template
     }
 
     /**
-     * @param string $template
+     * Render the template
+     * @param string $template The template path
+     * @param boolean $clearFlashMessages Clear the $_SESSION variables for flash messages
      */
-    public function display($template)
+    public function display($template, $clearFlashMessages = true)
     {
         $this->assign('flash_messages', Display::getFlashToString());
-        Display::cleanFlashMessages();
+
+        if ($clearFlashMessages) {
+            Display::cleanFlashMessages();
+        }
+
         echo $this->twig->render($template, $this->params);
     }