Mark events as not visible when they're not found or in the wrong room

src/service/rooms/state_accessor.rs

@@ -215,6 +215,14 @@ impl Service {
     ) -> Result<bool> {
         let lookup = Lookup::VisibilityForUser;
 
+        let Some(pdu) = services().rooms.timeline.get_pdu(event_id)? else {
+            return Ok(false);
+        };
+
+        if pdu.room_id() != room_id {
+            return Ok(false);
+        }
+
         let Some(shortstatehash) = self.pdu_shortstatehash(event_id)? else {
             return Ok(true);
         };