Merge pull request #3815 from matrix-org/andybalaam/redactions-move-t…

…o-main-when-actioned

Move the redaction event to main at the same time we move redacted

src/models/event.ts

@@ -1197,6 +1197,7 @@ export class MatrixEvent extends TypedEventEmitter<MatrixEventEmittedEvents, Mat
         // to the main timeline. This will change if MSC3389 is merged.
         if (room && !this.isThreadRoot && this.threadRootId && this.threadRootId !== this.getId()) {
             this.moveAllRelatedToMainTimeline(room);
+            redactionEvent.moveToMainTimeline(room);
         }
 
         this.invalidateExtensibleEvent();

src/models/room.ts

@@ -236,8 +236,9 @@ export type RoomEventHandlerMap = {
      *
      * @param event - The matrix redaction event
      * @param room - The room containing the redacted event
+     * @param threadId - The thread containing the redacted event (before it was redacted)
      */
-    [RoomEvent.Redaction]: (event: MatrixEvent, room: Room) => void;
+    [RoomEvent.Redaction]: (event: MatrixEvent, room: Room, threadId?: string) => void;
     /**
      * Fires when an event that was previously redacted isn't anymore.
      * This happens when the redaction couldn't be sent and
@@ -2113,6 +2114,12 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
      * Relations (other than m.thread), redactions, replies to a thread root live only in the main timeline
      * Relations, redactions, replies where the parent cannot be found live in no timelines but should be aggregated regardless.
      * Otherwise, the event lives in the main timeline only.
+     *
+     * Note: when a redaction is applied, the redacted event, events relating
+     * to it, and the redaction event itself, will all move to the main thread.
+     * This method classifies them as inside the thread of the redacted event.
+     * They are moved later as part of makeRedacted.
+     * This will change if MSC3389 is merged.
      */
     public eventShouldLiveIn(
         event: MatrixEvent,
@@ -2329,6 +2336,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
             // if we know about this event, redact its contents now.
             const redactedEvent = redactId ? this.findEventById(redactId) : undefined;
             if (redactedEvent) {
+                const threadRootId = redactedEvent.threadRootId;
                 redactedEvent.makeRedacted(event, this);
 
                 // If this is in the current state, replace it with the redacted version
@@ -2342,7 +2350,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                     }
                 }
 
-                this.emit(RoomEvent.Redaction, event, this);
+                this.emit(RoomEvent.Redaction, event, this, threadRootId);
 
                 // TODO: we stash user displaynames (among other things) in
                 // RoomMember objects which are then attached to other events
@@ -2495,7 +2503,7 @@ export class Room extends ReadReceipt<RoomEmittedEvents, RoomEventHandlerMap> {
                 }
                 if (redactedEvent) {
                     redactedEvent.markLocallyRedacted(event);
-                    this.emit(RoomEvent.Redaction, event, this);
+                    this.emit(RoomEvent.Redaction, event, this, redactedEvent.threadRootId);
                 }
             }
         } else {

src/models/thread.ts

@@ -228,8 +228,8 @@ export class Thread extends ReadReceipt<ThreadEmittedEvents, ThreadEventHandlerM
         }
     };
 
-    private onRedaction = async (event: MatrixEvent): Promise<void> => {
-        if (event.threadRootId !== this.id) return; // ignore redactions for other timelines
+    private onRedaction = async (event: MatrixEvent, room: Room, threadRootId?: string): Promise<void> => {
+        if (threadRootId !== this.id) return; // ignore redactions for other timelines
         if (this.replyCount <= 0) {
             for (const threadEvent of this.timeline) {
                 this.clearEventMetadata(threadEvent);