fix(timeline): maintain aggregations when an event is deduplicated

bindings/matrix-sdk-ffi/src/timeline/mod.rs

@@ -1040,6 +1040,7 @@ pub struct EventTimelineItem {
 impl From<matrix_sdk_ui::timeline::EventTimelineItem> for EventTimelineItem {
     fn from(item: matrix_sdk_ui::timeline::EventTimelineItem) -> Self {
         let reactions = item
+            .content()
             .reactions()
             .iter()
             .map(|(k, v)| Reaction {

crates/matrix-sdk-ui/CHANGELOG.md

@@ -6,6 +6,18 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased] - ReleaseDate
 
+### Bug Fixes
+
+### Features
+
+### Refactor
+
+- [**breaking**] Reactions on a given timeline item have been moved from
+  [`EventTimelineItem::reactions()`] to [`TimelineItemContent::reactions()`]; they're thus available
+  from an [`EventTimelineItem`] by calling `.content().reactions()`. They're also returned by
+  ownership (cloned) instead of by reference.
+  ([#4576](https://github.com/matrix-org/matrix-rust-sdk/pull/4576))
+
 ## [0.10.0] - 2025-02-04
 
 ### Bug Fixes

crates/matrix-sdk-ui/src/timeline/algorithms.rs

@@ -39,7 +39,13 @@ impl EventTimelineItemWithId<'_> {
     /// Create a clone of the underlying [`TimelineItem`] with the given
     /// reactions.
     pub fn with_reactions(&self, reactions: ReactionsByKeyBySender) -> Arc<TimelineItem> {
-        let event_item = self.inner.with_reactions(reactions);
+        let content = self.inner.content().with_reactions(reactions);
+
+        // Do not use `Self::with_content` which may override the latest_edit_json.
+        // TODO: it's likely incorrect?
+        let mut event_item = self.inner.clone();
+        event_item.content = content;
+
         TimelineItem::new(event_item, self.internal_id.clone())
     }
 }