objectcache: Make protected WANObjectCache::makePurgeValue non-static

It was already used everywhere as non-static via $this.
This is needed in order to allow MessageBlobStore unit tests
to disable the holdoff via a mock (mocks can't override static methods).

Change-Id: I3aad5b6e780addf1b6ce9de56c81b91f5ab358b2

diff --git a/includes/libs/objectcache/WANObjectCache.php b/includes/libs/objectcache/WANObjectCache.php
index 95bf743..8bdafcf 100644 (file)
--- a/includes/libs/objectcache/WANObjectCache.php
+++ b/includes/libs/objectcache/WANObjectCache.php
@@ -1091,7 +1091,7 @@ class WANObjectCache implements IExpiringStore, LoggerAwareInterface {
         * @param int $holdoff In seconds
         * @return string Wrapped purge value
         */
-       protected static function makePurgeValue( $timestamp, $holdoff ) {
+       protected function makePurgeValue( $timestamp, $holdoff ) {
                return self::PURGE_VAL_PREFIX . (float)$timestamp . ':' . (int)$holdoff;
        }
 }