From d0e8802b9dfb1fc34227d960636a4ddf6e0f1121 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Tue, 11 Apr 2023 20:54:56 +0400
Subject: [PATCH] Allow who viewed lists in topic groups.

---
 Telegram/SourceFiles/api/api_who_reacted.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Telegram/SourceFiles/api/api_who_reacted.cpp b/Telegram/SourceFiles/api/api_who_reacted.cpp
index 86e0a5881a..6fc8800b9d 100644
--- a/Telegram/SourceFiles/api/api_who_reacted.cpp
+++ b/Telegram/SourceFiles/api/api_who_reacted.cpp
@@ -619,8 +619,11 @@ bool WhoReadExists(not_null<HistoryItem*> item) {
 		return false;
 	}
 	const auto type = DetectSeenType(item);
+	const auto thread = item->topic()
+		? (Data::Thread*)item->topic()
+		: item->history();
 	const auto unseen = (type == Ui::WhoReadType::Seen)
-		? item->unread(item->history())
+		? item->unread(thread)
 		: item->isUnreadMedia();
 	if (unseen) {
 		return false;
@@ -630,7 +633,6 @@ bool WhoReadExists(not_null<HistoryItem*> item) {
 	const auto chat = peer->asChat();
 	const auto megagroup = peer->asMegagroup();
 	if ((!chat && !megagroup)
-		|| peer->isForum()
 		|| (megagroup
 			&& (megagroup->flags() & ChannelDataFlag::ParticipantsHidden))) {
 		return false;