MDL-53566 core: Add support for context locking

This chagne adds support for a new feature known as Context Locking.
This allows a context to be locked, thereby removing all write
capabilities for all users (including admin) for that context, and all
child contexts.

cohort/lib.php

@@ -634,4 +634,4 @@ function cohort_get_list_of_themes() {
         }
     }
     return $themes;
-}
+}

course/classes/category.php

@@ -238,6 +238,7 @@ public static function get($id, $strictness = MUST_EXIST, $alwaysreturnhidden =
                 $record->visible = 1;
                 $record->depth = 0;
                 $record->path = '';
+                $record->locked = 0;
                 self::$coursecat0 = new self($record);
             }
             return self::$coursecat0;
@@ -2458,6 +2459,7 @@ public function prepare_to_cache() {
         $context = $this->get_context();
         $a['xi'] = $context->id;
         $a['xp'] = $context->path;
+        $a['xl'] = $context->locked;
         return $a;
     }
 
@@ -2486,6 +2488,7 @@ public static function wake_from_cache($a) {
         $record->ctxdepth = $record->depth + 1;
         $record->ctxlevel = CONTEXT_COURSECAT;
         $record->ctxinstance = $record->id;
+        $record->ctxlocked = $a['xl'];
         return new self($record, true);
     }
 

lang/en/role.php

@@ -411,6 +411,7 @@
 $string['site:manageallmessaging'] = 'Add, remove, block and unblock contacts for any user';
 $string['site:manageblocks'] = 'Manage blocks on a page';
 $string['site:messageanyuser'] = 'Bypass user privacy preferences for messaging any user';
+$string['site:managecontextlocks'] = 'Manage locking of site contexts';
 $string['site:mnetloginfromremote'] = 'Login from a remote application via MNet';
 $string['site:mnetlogintoremote'] = 'Roam to a remote application via MNet';
 $string['site:readallmessages'] = 'Read all messages on site';