From e8d63c1a9d39018739bb37d54400cc5166f92750 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 29 Aug 2024 17:19:49 +0100
Subject: [PATCH 1/3] Fix background update for sliding sync (find previous
 membership)

---
 synapse/storage/databases/main/events_bg_updates.py | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/synapse/storage/databases/main/events_bg_updates.py b/synapse/storage/databases/main/events_bg_updates.py
index 3160e12bb30..b86f873eba2 100644
--- a/synapse/storage/databases/main/events_bg_updates.py
+++ b/synapse/storage/databases/main/events_bg_updates.py
@@ -1967,12 +1967,13 @@ def _find_previous_membership_txn(
             txn.execute(
                 """
                 SELECT event_id, membership
-                FROM room_memberships
+                FROM room_memberships AS m
+                INNER JOIN events AS e USING (room_id, event_id)
                 WHERE
                     room_id = ?
-                    AND user_id = ?
-                    AND event_stream_ordering < ?
-                ORDER BY event_stream_ordering DESC
+                    AND m.user_id = ?
+                    AND e.stream_ordering < ?
+                ORDER BY e.stream_ordering DESC
                 LIMIT 1
                 """,
                 (

From 3340f18ddbe8644d9144a06942d6c1884665e0c4 Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 29 Aug 2024 17:20:18 +0100
Subject: [PATCH 2/3] Newsfile

---
 changelog.d/17632.misc | 1 +
 1 file changed, 1 insertion(+)
 create mode 100644 changelog.d/17632.misc

diff --git a/changelog.d/17632.misc b/changelog.d/17632.misc
new file mode 100644
index 00000000000..2f81356d127
--- /dev/null
+++ b/changelog.d/17632.misc
@@ -0,0 +1 @@
+Store sliding sync per-connection state in the database.

From e4f731becc4c7bb97d623cd3bdd16d5665ef313f Mon Sep 17 00:00:00 2001
From: Erik Johnston <erik@matrix.org>
Date: Thu, 29 Aug 2024 17:25:23 +0100
Subject: [PATCH 3/3] Newsfile

---
 changelog.d/17632.misc | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/changelog.d/17632.misc b/changelog.d/17632.misc
index 2f81356d127..756918e2b21 100644
--- a/changelog.d/17632.misc
+++ b/changelog.d/17632.misc
@@ -1 +1 @@
-Store sliding sync per-connection state in the database.
+Pre-populate room data used in experimental [MSC3575](https://github.com/matrix-org/matrix-spec-proposals/pull/3575) Sliding Sync `/sync` endpoint for quick filtering/sorting.