Return broken messages unchanged from messages()

Without this change, a batch with a message that cannot be deserialized
(for whatever reason) means that the batch cannot be processed at all by
the caller. Now, those messages are returned unchanged in the batch so
that the caller can handle them.

crates/matrix-sdk/src/room/common.rs

@@ -132,6 +132,10 @@ impl Common {
     /// returns a `Messages` struct that contains a chunk of room and state
     /// events (`RoomEvent` and `AnyStateEvent`).
     ///
+    /// With the encryption feature, messages are decrypted if possible. If
+    /// decryption fails for an individual message, that message is returned
+    /// undecrypted.
+    ///
     /// # Arguments
     ///
     /// * `request` - The easiest way to create this request is using the
@@ -175,14 +179,19 @@ impl Common {
             state: http_response.state,
         };
 
-        for event in &http_response.chunk {
-            let event = event.deserialize()?;
-
+        for event in http_response.chunk {
             #[cfg(feature = "encryption")]
-            let event = self.client.decrypt_room_event(&event).await?;
+            let event = match event.deserialize() {
+                Ok(event) => self.client.decrypt_room_event(&event).await?,
+                Err(_) => {
+                    // "Broken" messages (i.e., those that cannot be deserialized) are
+                    // returned unchanged so that the caller can handle them individually.
+                    RoomEvent { event, encryption_info: None }
+                }
+            };
 
             #[cfg(not(feature = "encryption"))]
-            let event = RoomEvent { event: Raw::new(&event)?, encryption_info: None };
+            let event = RoomEvent { event, encryption_info: None };
 
             response.chunk.push(event);
         }