From b94ab42c90eddd62ffb95a2fb4957cf5588a2ca7 Mon Sep 17 00:00:00 2001
From: Bruno Windels <bruno@windels.cloud>
Date: Thu, 3 Jun 2021 19:10:29 +0200
Subject: [PATCH] delete annotations object when no more annotations left

---
 .../room/timeline/persistence/RelationWriter.js      | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/matrix/room/timeline/persistence/RelationWriter.js b/src/matrix/room/timeline/persistence/RelationWriter.js
index b15f2800..3838c494 100644
--- a/src/matrix/room/timeline/persistence/RelationWriter.js
+++ b/src/matrix/room/timeline/persistence/RelationWriter.js
@@ -171,6 +171,9 @@ export class RelationWriter {
         const relations = await txn.timelineRelations.getForTargetAndType(this._roomId, targetId, ANNOTATION_RELATION_TYPE);
         log.set("relations", relations.length);
         delete target.annotations[key];
+        if (isObjectEmpty(target.annotations)) {
+            delete target.annotations;
+        }
         await Promise.all(relations.map(async relation => {
             const annotation = await txn.timelineEvents.getByEventId(this._roomId, relation.sourceEventId);
             if (!annotation) {
@@ -184,6 +187,15 @@ export class RelationWriter {
     }
 }
 
+function isObjectEmpty(obj) {
+    for (const key in obj) {
+        if (obj.hasOwnProperty(key)) {
+            return false;
+        }
+    }
+    return true;
+}
+
 // copied over from matrix-js-sdk, copyright 2016 OpenMarket Ltd
 /* _REDACT_KEEP_KEY_MAP gives the keys we keep when an event is redacted
  *