MDL-86416 navigation: Render the more menu only when it's not empty

Co-authored-by: Jun Pataleta <[email protected]>

public/lib/classes/navigation/output/more_menu.php

@@ -83,6 +83,10 @@ class more_menu implements renderable, templatable {
             $data['nodecollection'] = $this->content;
         } else {
             $data['nodearray'] = (array) $this->content;
+            // If there is no node array to render then return an empty array.
+            if (empty($data['nodearray'])) {
+                return [];
+            }
         }
         $data['moremenuid'] = uniqid();
 

public/lib/tests/navigation/output/more_menu_test.php

@@ -0,0 +1,46 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace core\navigation\output;
+
+use basic_testcase;
+use core\output\renderer_base;
+use stdClass;
+
+/**
+ * More menu navigation renderable test.
+ *
+ * @package     core
+ * @category    navigation
+ * @copyright   Stefan Topfstedt
+ * @license     http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @covers      \core\navigation\output\more_menu
+ */
+final class more_menu_test extends basic_testcase {
+    /**
+     * Checks that export_for_template() returns an empty array if the given content is empty.
+     * See MDL-86416.
+     *
+     * @return void
+     */
+    public function test_export_for_template_returns_empty_array(): void {
+        $moremenu = new more_menu(new stdClass(), 'whatever', false, false);
+        $output = $this->createStub(renderer_base::class);
+        $data = $moremenu->export_for_template($output);
+        $this->assertIsArray($data);
+        $this->assertEmpty($data);
+    }
+}