fixup! memorystore: store received room key bundle data

Author: richvdh

crates/matrix-sdk-crypto/src/store/memorystore.rs

@@ -103,7 +103,8 @@ pub struct MemoryStore {
     dehydrated_device_pickle_key: RwLock<Option<DehydratedDeviceKey>>,
     next_batch_token: RwLock<Option<String>>,
     room_settings: StdRwLock<HashMap<OwnedRoomId, RoomSettings>>,
-    room_key_bundles: StdRwLock<HashMap<OwnedRoomId, Vec<StoredRoomKeyBundleData>>>,
+    room_key_bundles:
+        StdRwLock<HashMap<OwnedRoomId, HashMap<OwnedUserId, StoredRoomKeyBundleData>>>,
 
     save_changes_lock: Arc<Mutex<()>>,
 }
@@ -328,7 +329,7 @@ impl CryptoStore for MemoryStore {
                 room_key_bundles
                     .entry(bundle.bundle_data.room_id.clone())
                     .or_default()
-                    .push(bundle);
+                    .insert(bundle.sender_user.clone(), bundle);
             }
         }
 
@@ -710,10 +711,7 @@ impl CryptoStore for MemoryStore {
     ) -> Result<Option<StoredRoomKeyBundleData>> {
         let guard = self.room_key_bundles.read();
 
-        let result = guard.get(room_id).and_then(|bundles| {
-            // Find the most recently-added entry from this user
-            bundles.iter().rfind(|b| b.sender_user == user_id).cloned()
-        });
+        let result = guard.get(room_id).and_then(|bundles| bundles.get(user_id).cloned());
 
         Ok(result)
     }