MDL-83163 core_course: Fresh install fails if dependency on format

If any plugin had dependency on a course format, Moodle fresh install
showed dependency errors (even though course format exists).

course/lib.php

@@ -2894,7 +2894,11 @@ function include_course_editor(course_format $format) {
 function get_sorted_course_formats($enabledonly = false) {
     global $CFG;
 
-    $formats = core_plugin_manager::instance()->get_installed_plugins('format');
+    // Include both formats that exist on disk (but might not have been installed yet), and those
+    // which were installed but no longer exist on disk.
+    $installedformats = core_plugin_manager::instance()->get_installed_plugins('format');
+    $existingformats = core_component::get_plugin_list('format');
+    $formats = array_merge($installedformats, $existingformats);
 
     if (!empty($CFG->format_plugins_sortorder)) {
         $order = explode(',', $CFG->format_plugins_sortorder);

course/tests/courselib_test.php

@@ -7502,4 +7502,36 @@ public function test_course_section_view(): void {
         $this->assertEquals('course_sections', $event->objecttable);
         $this->assertEquals($section->id, $event->objectid);
     }
+
+    /**
+     * Tests get_sorted_course_formats returns all plugins in cases where plugins are installed now,
+     * installed previously but no longer exist, or not installed yet.
+     *
+     * @covers ::get_sorted_course_formats()
+     */
+    public function test_get_sorted_course_formats_installed_or_not(): void {
+        global $DB;
+
+        $this->resetAfterTest();
+
+        // By default returns all course formats.
+        $formats = get_sorted_course_formats();
+        $this->assertEquals(['topics', 'weeks', 'singleactivity', 'social'], $formats);
+
+        // If there is an extra format installed that no longer exists, include in list (at end).
+        $DB->insert_record('config_plugins', [
+            'plugin' => 'format_frogs',
+            'name' => 'version',
+            'value' => '20240916',
+        ]);
+        \core\plugin_manager::reset_caches();
+        $formats = get_sorted_course_formats();
+        $this->assertEquals(['topics', 'weeks', 'singleactivity', 'social', 'frogs'], $formats);
+
+        // If one of the formats is not installed yet, we still return it.
+        $DB->delete_records('config_plugins', ['plugin' => 'format_weeks']);
+        \core\plugin_manager::reset_caches();
+        $formats = get_sorted_course_formats();
+        $this->assertEquals(['topics', 'weeks', 'singleactivity', 'social', 'frogs'], $formats);
+    }
 }