Merge pull request #24387 from owncloud/locking-mark-reload-free

free up memory when releasing the last shared lock

Author: DeepDiver1975

lib/private/Lock/AbstractLockingProvider.php

@@ -77,6 +77,9 @@ protected function markRelease($path, $type) {
 		if ($type === self::LOCK_SHARED) {
 			if (isset($this->acquiredLocks['shared'][$path]) and $this->acquiredLocks['shared'][$path] > 0) {
 				$this->acquiredLocks['shared'][$path]--;
+				if ($this->acquiredLocks['shared'][$path] === 0) {
+					unset($this->acquiredLocks['shared'][$path]);
+				}
 			}
 		} else if ($type === self::LOCK_EXCLUSIVE) {
 			unset($this->acquiredLocks['exclusive'][$path]);