Stop when a mid result is empty

1 files changed, 8 insertions, 2 deletions

diff --git a/apps/dav/lib/connector/sabre/filesreportplugin.php b/apps/dav/lib/connector/sabre/filesreportplugin.php
index d7e4f8beda1..141b684360e 100644
--- a/apps/dav/lib/connector/sabre/filesreportplugin.php
+++ b/apps/dav/lib/connector/sabre/filesreportplugin.php
@@ -211,7 +211,7 @@ class FilesReportPlugin extends ServerPlugin {
 	 */
 	public function processFilterRules($filterRules) {
 		$ns = '{' . $this::NS_OWNCLOUD . '}';
-		$resultFileIds = [];
+		$resultFileIds = null;
 		$systemTagIds = [];
 		foreach ($filterRules as $filterRule) {
 			if ($filterRule['name'] === $ns . 'systemtag') {
@@ -240,15 +240,21 @@ class FilesReportPlugin extends ServerPlugin {
 			$fileIds = $this->tagMapper->getObjectIdsForTags($systemTagId, 'files');
 
 			if (empty($fileIds)) {
+				// This tag has no files, nothing can ever show up
 				return [];
 			}
 
 			// first run ?
-			if (empty($resultFileIds)) {
+			if ($resultFileIds === null) {
 				$resultFileIds = $fileIds;
 			} else {
 				$resultFileIds = array_intersect($resultFileIds, $fileIds);
 			}
+
+			if (empty($resultFileIds)) {
+				// Empty intersection, nothing can show up anymore
+				return [];
+			}
 		}
 		return $resultFileIds;
 	}