From ada0b3184b46a800be293c843fd6431e63403bf9 Mon Sep 17 00:00:00 2001
From: Ginger <ginger@gingershaped.computer>
Date: Sat, 11 Jul 2026 10:39:30 -0400
Subject: [PATCH] fix: Properly sync newly created rooms

---
 changelog.d/+88fbb987.bugfix.md  |  1 +
 src/api/client/sync/v3/joined.rs | 25 +++++++++++++++----------
 2 files changed, 16 insertions(+), 10 deletions(-)
 create mode 100644 changelog.d/+88fbb987.bugfix.md

diff --git a/changelog.d/+88fbb987.bugfix.md b/changelog.d/+88fbb987.bugfix.md
new file mode 100644
index 000000000..0fb997e3a
--- /dev/null
+++ b/changelog.d/+88fbb987.bugfix.md
@@ -0,0 +1 @@
+Fixed newly created rooms failing to sync properly in clients using legacy sync.
diff --git a/src/api/client/sync/v3/joined.rs b/src/api/client/sync/v3/joined.rs
index d225a1e5c..20bcda294 100644
--- a/src/api/client/sync/v3/joined.rs
+++ b/src/api/client/sync/v3/joined.rs
@@ -381,16 +381,21 @@ async fn fetch_shortstatehashes(
 				| Some((_, pdu_after_last_sync_end)) => {
 					trace!(?pdu_after_last_sync_end.event_id, "pdu at last sync end");
 
-					Some(
-						services
-							.rooms
-							.state_accessor
-							.pdu_shortstatehash(&pdu_after_last_sync_end.event_id)
-							.await
-							.map_err(|err| {
-								err!("Last sync end PDU has no shortstatehash: {err}")
-							}),
-					)
+					if pdu_after_last_sync_end.kind == RoomCreate {
+						// Room create events have no previous state
+						None
+					} else {
+						Some(
+							services
+								.rooms
+								.state_accessor
+								.pdu_shortstatehash(&pdu_after_last_sync_end.event_id)
+								.await
+								.map_err(|err| {
+									err!("Last sync end PDU has no shortstatehash: {err}")
+								}),
+						)
+					}
 				},
 				| None => {
 					// No events have been sent since the last sync, or we just joined this room