fix: Merge nex/fix-redactions-boogaloo-2

src/api/client/send.rs

@@ -6,7 +6,10 @@
 	matrix::pdu::{PartialPdu, sticky},
 	utils,
 };
-use ruma::{api::client::message::send_message_event, events::MessageLikeEventType};
+use ruma::{
+	OwnedEventId, api::client::message::send_message_event, events::MessageLikeEventType,
+};
+use serde::Deserialize;
 use serde_json::from_str;
 
 use crate::{Ruma, client_ip::ClientIp};
@@ -77,6 +80,13 @@ pub(crate) async fn send_message_event_route(
 
 	let content = from_str(body.body.body.json().get())
 		.map_err(|e| err!(Request(BadJson("Invalid JSON body: {e}"))))?;
+	let redacts = if body.body.event_type == MessageLikeEventType::RoomRedaction {
+		from_str::<MaybeRedaction>(body.body.body.json().get())
+			.ok()
+			.and_then(|r| r.redacts)
+	} else {
+		None
+	};
 
 	let event_id = services
 		.rooms
@@ -92,11 +102,14 @@ pub(crate) async fn send_message_event_route(
 					.flatten()
 					.map(sticky::object),
 				unsigned: Some(unsigned),
-				timestamp: if body.identity.is_appservice() {
+				timestamp: if body.identity.is_appservice()
+					|| services.admin.user_is_admin(sender_user).await
+				{
 					body.timestamp
 				} else {
 					None
 				},
+				redacts,
 				..Default::default()
 			},
 			sender_user,
@@ -116,3 +129,11 @@ pub(crate) async fn send_message_event_route(
 
 	Ok(send_message_event::v3::Response::new(event_id))
 }
+
+/// Struct containing exclusively the `redacts` field for MSC4169 compatible
+/// redaction moving.
+#[derive(Deserialize)]
+struct MaybeRedaction {
+	#[serde(default)]
+	redacts: Option<OwnedEventId>,
+}

src/core/matrix/event/redact.rs

@@ -56,7 +56,12 @@ pub(super) fn is_redacted<E: Event>(event: &E) -> bool {
 		return false;
 	};
 
-	unsigned.redacted_because.is_some()
+	unsigned.redacted_by.is_some()
+}
+
+#[derive(Deserialize)]
+struct RedactionField {
+	redacts: OwnedEventId,
 }
 
 #[must_use]
@@ -69,16 +74,104 @@ pub(super) fn redacts_id<E: Event>(
 	}
 
 	if room_version_rules.redaction.content_field_redacts {
-		event.redacts().map(ToOwned::to_owned)
-	} else {
 		event
-			.get_content::<RoomRedactionEventContent>()
-			.ok()?
-			.redacts
+			.get_content::<RedactionField>()
+			.map(|r| r.redacts)
+			.ok()
+	} else {
+		event.redacts().map(ToOwned::to_owned)
 	}
 }
 
 #[derive(Deserialize)]
 struct ExtractRedactedBecause {
-	redacted_because: Option<serde::de::IgnoredAny>,
+	#[serde(rename = "org.continuwuity.redacted_by")]
+	redacted_by: Option<serde::de::IgnoredAny>,
+}
+
+#[cfg(test)]
+mod tests {
+	use ruma::{UInt, events::TimelineEventType, room_version_rules::RoomVersionRules};
+	use serde_json::json;
+
+	use crate::{Event, Pdu, pdu::EventHash};
+
+	#[test]
+	fn v11_redacts_from_content() {
+		let p = Pdu {
+			event_id: ruma::owned_event_id!("$v11"),
+			room_id: Some(ruma::owned_room_id!("!v11:example.com")),
+			sender: ruma::owned_user_id!("@user:example.com"),
+			origin: None,
+			origin_server_ts: UInt::default(),
+			kind: TimelineEventType::RoomRedaction,
+			content: serde_json::value::to_raw_value(&json!({"redacts": "$content_redacts"}))
+				.unwrap(),
+			sticky: None,
+			state_key: None,
+			prev_events: vec![],
+			depth: UInt::default(),
+			auth_events: vec![],
+			redacts: Some(ruma::owned_event_id!("$apex_redacts")),
+			unsigned: None,
+			hashes: EventHash { sha256: String::new() },
+			signatures: None,
+		};
+		assert_eq!(
+			p.redacts_id(&RoomVersionRules::V11),
+			Some(ruma::owned_event_id!("$content_redacts"))
+		);
+	}
+
+	#[test]
+	fn v10_redacts_from_apex() {
+		let p = Pdu {
+			event_id: ruma::owned_event_id!("$v11"),
+			room_id: Some(ruma::owned_room_id!("!v11:example.com")),
+			sender: ruma::owned_user_id!("@user:example.com"),
+			origin: None,
+			origin_server_ts: UInt::default(),
+			kind: TimelineEventType::RoomRedaction,
+			content: serde_json::value::to_raw_value(&json!({"redacts": "$content_redacts"}))
+				.unwrap(),
+			sticky: None,
+			state_key: None,
+			prev_events: vec![],
+			depth: UInt::default(),
+			auth_events: vec![],
+			redacts: Some(ruma::owned_event_id!("$apex_redacts")),
+			unsigned: None,
+			hashes: EventHash { sha256: String::new() },
+			signatures: None,
+		};
+		assert_eq!(
+			p.redacts_id(&RoomVersionRules::V10),
+			Some(ruma::owned_event_id!("$apex_redacts"))
+		);
+	}
+
+	#[test]
+	fn redacts_ignores_non_redaction_event() {
+		let p = Pdu {
+			event_id: ruma::owned_event_id!("$v11"),
+			room_id: Some(ruma::owned_room_id!("!v11:example.com")),
+			sender: ruma::owned_user_id!("@user:example.com"),
+			origin: None,
+			origin_server_ts: UInt::default(),
+			kind: TimelineEventType::RoomMessage,
+			content: serde_json::value::to_raw_value(&json!({"redacts": "$content_redacts"}))
+				.unwrap(),
+			sticky: None,
+			state_key: None,
+			prev_events: vec![],
+			depth: UInt::default(),
+			auth_events: vec![],
+			redacts: Some(ruma::owned_event_id!("$apex_redacts")),
+			unsigned: None,
+			hashes: EventHash { sha256: String::new() },
+			signatures: None,
+		};
+		assert_eq!(p.redacts_id(&RoomVersionRules::V11), None);
+		assert_eq!(p.redacts_id(&RoomVersionRules::V10), None);
+	}
 }

src/service/rooms/timeline/create.rs

@@ -183,11 +183,6 @@ pub async fn create_event(
 					.room_state_get(room_id, &event_type.clone().to_string().into(), state_key)
 					.await
 				{
-					unsigned.insert("prev_content".to_owned(), prev_pdu.get_content_as_value());
-					unsigned.insert(
-						"prev_sender".to_owned(),
-						serde_json::to_value(prev_pdu.sender())?,
-					);
 					unsigned.insert(
 						"replaces_state".to_owned(),
 						serde_json::to_value(prev_pdu.event_id())?,
@@ -195,9 +190,17 @@ pub async fn create_event(
 				}
 			}
 		}
+		let redacts = match redacts {
+			// If this isn't a real redaction event, there's no redacts field.
+			| _ if event_type != TimelineEventType::RoomRedaction || state_key.is_some() => None,
+			// If the redaction is itself in the event content, we don't set the top-level field.
+			| Some(_) if room_version_rules.redaction.content_field_redacts => None,
+			// Otherwise, we do if it's present
+			| other => other,
+		};
 
 		let pdu = PduEvent {
-			event_id: ruma::event_id!("$thiswillbefilledinlater").into(),
+			event_id: ruma::owned_event_id!("$thiswillbefilledinlater"),
 			room_id: room_id.map(ToOwned::to_owned),
 			sender: sender.to_owned(),
 			origin: None,