Sync reactions after getMessageAddedReactions if needed.

td/telegram/MessageReaction.cpp

@@ -176,6 +176,7 @@ class GetMessageReactionsListQuery final : public Td::ResultHandler {
     }
 
     vector<td_api::object_ptr<td_api::addedReaction>> reactions;
+    FlatHashMap<string, vector<DialogId>> recent_reactions;
     for (const auto &reaction : ptr->reactions_) {
       DialogId dialog_id(reaction->peer_id_);
       if (!dialog_id.is_valid() ||
@@ -184,12 +185,21 @@ class GetMessageReactionsListQuery final : public Td::ResultHandler {
         continue;
       }
 
+      if (offset_.empty()) {
+        recent_reactions[reaction->reaction_].push_back(dialog_id);
+      }
+
       auto message_sender = get_min_message_sender_object(td_, dialog_id, "GetMessageReactionsListQuery");
       if (message_sender != nullptr) {
         reactions.push_back(td_api::make_object<td_api::addedReaction>(reaction->reaction_, std::move(message_sender)));
       }
     }
 
+    if (offset_.empty()) {
+      td_->messages_manager_->on_get_message_reaction_list({dialog_id_, message_id_}, reaction_,
+                                                           std::move(recent_reactions), total_count);
+    }
+
     promise_.set_value(
         td_api::make_object<td_api::addedReactions>(total_count, std::move(reactions), ptr->next_offset_));
   }

td/telegram/MessagesManager.cpp

@@ -6810,6 +6810,60 @@ void MessagesManager::update_message_reactions(FullMessageId full_message_id,
   update_message_interaction_info(full_message_id, -1, -1, false, nullptr, true, std::move(reactions));
 }
 
+void MessagesManager::on_get_message_reaction_list(FullMessageId full_message_id, const string &reaction,
+                                                   FlatHashMap<string, vector<DialogId>> reactions, int32 total_count) {
+  const Message *m = get_message_force(full_message_id, "on_get_message_reaction_list");
+  if (m == nullptr || m->reactions == nullptr) {
+    return;
+  }
+
+  auto are_consistent = [](const vector<DialogId> &lhs, const vector<DialogId> &rhs) {
+    size_t i = 0;
+    size_t max_i = td::min(lhs.size(), rhs.size());
+    while (i < max_i && lhs[i] == rhs[i]) {
+      i++;
+    }
+    return i == max_i;
+  };
+
+  // it's impossible to use received reactions to update message reactions, because there is no way to find,
+  // which reaction is chosen by the current user, so just reload message reactions for consistency
+  bool need_reload = false;
+  if (reaction.empty()) {
+    // received list and total_count for all reactions
+    int32 old_total_count = 0;
+    for (const auto &message_reaction : m->reactions->reactions_) {
+      need_reload |=
+          !are_consistent(reactions[message_reaction.get_reaction()], message_reaction.get_recent_chooser_dialog_ids());
+      old_total_count += message_reaction.get_choose_count();
+      reactions.erase(message_reaction.get_reaction());
+    }
+    need_reload |= old_total_count != total_count || !reactions.empty();
+  } else {
+    // received list and total_count for a single reaction
+    const auto *message_reaction = m->reactions->get_reaction(reaction);
+    if (message_reaction == nullptr) {
+      need_reload = reactions.count(reaction) != 0 || total_count > 0;
+    } else {
+      need_reload = !are_consistent(reactions[reaction], message_reaction->get_recent_chooser_dialog_ids()) ||
+                    message_reaction->get_choose_count() != total_count;
+    }
+  }
+
+  if (!need_reload) {
+    return;
+  }
+
+  LOG(INFO) << "Need reload reactions in " << full_message_id << " for consistency";
+
+  auto it = pending_reactions_.find(full_message_id);
+  if (it != pending_reactions_.end()) {
+    it->second.was_updated = true;
+  } else {
+    reload_message_reactions(td_, full_message_id.get_dialog_id(), {full_message_id.get_message_id()});
+  }
+}
+
 void MessagesManager::on_update_message_interaction_info(FullMessageId full_message_id, int32 view_count,
                                                          int32 forward_count, bool has_reply_info,
                                                          tl_object_ptr<telegram_api::messageReplies> &&reply_info) {

td/telegram/MessagesManager.h

@@ -341,6 +341,9 @@ class MessagesManager final : public Actor {
 
   void update_message_reactions(FullMessageId full_message_id, unique_ptr<MessageReactions> &&reactions);
 
+  void on_get_message_reaction_list(FullMessageId full_message_id, const string &reaction,
+                                    FlatHashMap<string, vector<DialogId>> reactions, int32 total_count);
+
   void on_update_message_interaction_info(FullMessageId full_message_id, int32 view_count, int32 forward_count,
                                           bool has_reply_info,
                                           tl_object_ptr<telegram_api::messageReplies> &&reply_info);