Pending upstream PR #2546

@@ -1491,0 +1494,4 @@
+	/// by default. Users will need to use MSC4495-compatible clients to explicitly
+	/// opt in to presence sharing with other users.
+	///
+	/// If this is enabled, you probably also want to set `allow_outgoing_presence`.

@@ -1400,0 +1405,4 @@
+#
+# [MSC4495]: https://github.com/matrix-org/matrix-spec-proposals/pull/4495
+#
+#enable_msc4495_selective_presence = false

@@ -1240,0 +1241,4 @@
+	pub(super) async fn recalculate_presence_recipients(&self, user_id: OwnedUserId) -> Result {
+		self.bail_restricted()?;
+
+		let out = match self

@@ -487,2 +488,4 @@
 		.await?;
 
+	// 5.4 Presence Sharing
+	services

@@ -374,0 +396,4 @@
+
+			// Incremental update
+			| Some(prev_id)
+				if current_recipients.stream_id == <Int as Into<i64>>::into(prev_id) =>

@@ -162,2 +162,4 @@
 		..descriptor::SEQUENTIAL_SMALL
 	},
+	Descriptor {
+		name: "userid_recipients",

@@ -167,0 +238,4 @@
+						prev_recipients
+							.stream_id
+							.try_into()
+							.expect("js_int overflowed"),

@@ -167,0 +250,4 @@
+					);
+				},
+				| Err(e) => {
+					warn!("Failed to calculate presence recipients for {user_id}: {e}");

@@ -167,0 +265,4 @@
+				.chain(update.recipients.delete.iter())
+				.map(|u| u.server_name().to_owned())
+				.dedup()
+				.collect::<Vec<_>>()

@@ -167,0 +293,4 @@
+			let mut buf = EduBuf::new();
+			serde_json::to_writer(
+				&mut buf,
+				&Edu::Presence(PresenceContent::new(vec![server_update])),

@@ -278,0 +560,4 @@
+				.services
+				.users
+				.stream_local_users()
+				.filter(|local_user| {

@@ -278,0 +618,4 @@
+			return Ok(None);
+		}
+
+		let stream_id = self.services.globals.next_count()?.cast_signed();

@@ -193,1 +193,4 @@
 
+	/// Returns all servers that can see a user by sharing at least one room.
+	pub async fn servers_seeing_user(&self, user_id: &UserId) -> Vec<OwnedServerName> {
+		let rooms = self

@@ -194,0 +197,4 @@
+			.rooms_joined(user_id)
+			.collect::<Vec<OwnedRoomId>>()
+			.await;
+		let mut servers = Vec::new();