Add update permissions hook to sharing

lib/public/share.php

@@ -657,6 +657,15 @@ class Share {
 			}
 			$query = \OC_DB::prepare('UPDATE `*PREFIX*share` SET `permissions` = ? WHERE `id` = ?');
 			$query->execute(array($permissions, $item['id']));
+			\OC_Hook::emit('OCP\Share', 'post_update_permissions', array(
+				'itemType' => $itemType,
+				'itemSource' => $itemSource,
+				'itemTarget' => $itemTarget,
+				'shareType' => $shareType,
+				'shareWith' => $shareWith,
+				'uidOwner' => \OC_User::getUser(),
+				'permissions' => $permissions,
+			));
 			// Check if permissions were removed
 			if ($item['permissions'] & ~$permissions) {
 				// If share permission is removed all reshares must be deleted