From d458bf6be38963c3aae0fff08d7d2e974329b404 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 25 Jul 2025 13:05:41 +0400
Subject: [PATCH] Fix possible negative folder counters.

---
 Telegram/SourceFiles/history/history.cpp | 14 +++++++++-----
 Telegram/SourceFiles/history/history.h   |  1 +
 2 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/Telegram/SourceFiles/history/history.cpp b/Telegram/SourceFiles/history/history.cpp
index 3c8c10098e..ed146023f4 100644
--- a/Telegram/SourceFiles/history/history.cpp
+++ b/Telegram/SourceFiles/history/history.cpp
@@ -1983,13 +1983,17 @@ bool History::unreadCountKnown() const {
 	return _unreadCount.has_value();
 }
 
+bool History::useMyUnreadInParent() const {
+	return !isForum() && !amMonoforumAdmin();
+}
+
 void History::setUnreadCount(int newUnreadCount) {
 	Expects(folderKnown());
 
 	if (_unreadCount == newUnreadCount) {
 		return;
 	}
-	const auto notifier = unreadStateChangeNotifier(!isForum());
+	const auto notifier = unreadStateChangeNotifier(useMyUnreadInParent());
 	_unreadCount = newUnreadCount;
 
 	const auto lastOutgoing = [&] {
@@ -2028,7 +2032,7 @@ void History::setUnreadMark(bool unread) {
 		return;
 	}
 	const auto notifier = unreadStateChangeNotifier(
-		!unreadCount() && !isForum());
+		useMyUnreadInParent() && !unreadCount());
 	Thread::setUnreadMarkFlag(unread);
 }
 
@@ -2060,9 +2064,9 @@ void History::setMuted(bool muted) {
 	if (this->muted() == muted) {
 		return;
 	} else {
-		const auto state = isForum()
-			? Dialogs::BadgesState()
-			: computeBadgesState();
+		const auto state = useMyUnreadInParent()
+			? computeBadgesState()
+			: Dialogs::BadgesState();
 		const auto notify = (state.unread || state.reaction);
 		const auto notifier = unreadStateChangeNotifier(notify);
 		Thread::setMuted(muted);
diff --git a/Telegram/SourceFiles/history/history.h b/Telegram/SourceFiles/history/history.h
index 7f556bbc71..047a341094 100644
--- a/Telegram/SourceFiles/history/history.h
+++ b/Telegram/SourceFiles/history/history.h
@@ -608,6 +608,7 @@ private:
 
 	void hasUnreadMentionChanged(bool has) override;
 	void hasUnreadReactionChanged(bool has) override;
+	[[nodiscard]] bool useMyUnreadInParent() const;
 
 	const std::unique_ptr<HistoryMainElementDelegateMixin> _delegateMixin;