Merge branch 'MDL-69788' of https://github.com/paulholden/moodle

lib/adminlib.php

@@ -4933,6 +4933,36 @@ class admin_setting_langlist extends admin_setting_configtext {
         parent::__construct('langlist', get_string('langlist', 'admin'), get_string('configlanglist', 'admin'), '', PARAM_NOTAGS);
     }
 
+    /**
+     * Validate that each language identifier exists on the site
+     *
+     * @param string $data
+     * @return bool|string True if validation successful, otherwise error string
+     */
+    public function validate($data) {
+        $parentcheck = parent::validate($data);
+        if ($parentcheck !== true) {
+            return $parentcheck;
+        }
+
+        if ($data === '') {
+            return true;
+        }
+
+        // Normalize language identifiers.
+        $langcodes = array_map('trim', explode(',', $data));
+        foreach ($langcodes as $langcode) {
+            // If the langcode contains optional alias, split it out.
+            [$langcode, ] = preg_split('/\s*\|\s*/', $langcode, 2);
+
+            if (!get_string_manager()->translation_exists($langcode)) {
+                return get_string('invalidlanguagecode', 'error', $langcode);
+            }
+        }
+
+        return true;
+    }
+
     /**
      * Save the new setting
      *

lib/classes/string_manager_standard.php

@@ -533,7 +533,13 @@ class core_string_manager_standard implements core_string_manager {
                     $languages[$langcode] = !empty($this->transaliases[$langcode]) ? $this->transaliases[$langcode] : $langname;
                 }
             }
-            return $languages;
+
+            // If there are no valid enabled translations, then return all languages.
+            if (!empty($languages)) {
+                return $languages;
+            } else {
+                return $cachedlist;
+            }
         }
 
         // Get all languages available in system.
@@ -584,7 +590,12 @@ class core_string_manager_standard implements core_string_manager {
             }
         }
 
-        return $languages;
+        // If there are no valid enabled translations, then return all languages.
+        if (!empty($languages)) {
+            return $languages;
+        } else {
+            return $cachedlist;
+        }
     }
 
     /**

lib/tests/string_manager_standard_test.php

@@ -140,6 +140,13 @@ class core_string_manager_standard_testcase extends advanced_testcase {
 
         $this->assertEquals(['en' => 'En'], $stringman->get_list_of_translations());
 
+        // Set invalid config, ensure original list is returned.
+        set_config('langlist', 'xx');
+        $this->assertEquals(['en' => 'English ‎(en)‎'], get_string_manager(true)->get_list_of_translations());
+
+        set_config('langlist', 'xx,en|En');
+        $this->assertEquals(['en' => 'En'], get_string_manager(true)->get_list_of_translations());
+
         set_config('langlist', '');
         get_string_manager(true);
     }