From f0499e72695e716614beb3c3dd454f6c968a6b64 Mon Sep 17 00:00:00 2001
From: Michael <heluecht@pirati.ca>
Date: Thu, 28 Jul 2022 20:25:38 +0000
Subject: [PATCH] Use negative caching

---
 src/Protocol/ActivityPub/Processor.php | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/Protocol/ActivityPub/Processor.php b/src/Protocol/ActivityPub/Processor.php
index bfff5f84bb..3b31e6d3c4 100644
--- a/src/Protocol/ActivityPub/Processor.php
+++ b/src/Protocol/ActivityPub/Processor.php
@@ -1207,13 +1207,19 @@ class Processor
 		$object = DI::cache()->get($cachekey);
 
 		if (!is_null($object)) {
-			Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
+			if (!empty($object)) {
+				Logger::debug('Fetch from cache', ['url' => $url, 'uid' => $uid]);
+			} else {
+				Logger::debug('Fetch from negative cache', ['url' => $url, 'uid' => $uid]);
+			}
 			return $object;
 		}
 
 		$object = ActivityPub::fetchContent($url, $uid);
 		if (empty($object)) {
 			Logger::notice('Activity was not fetchable, aborting.', ['url' => $url, 'uid' => $uid]);
+			// We perform negative caching.
+			DI::cache()->set($cachekey, [], Duration::FIVE_MINUTES);
 			return [];
 		}