From ca548a11d7b6e183444d713768ee7ff5fd59e207 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 26 Apr 2019 17:23:32 +0400
Subject: [PATCH] Fix assertion violation in History::inboxRead().

---
 Telegram/SourceFiles/history/history.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Telegram/SourceFiles/history/history.cpp b/Telegram/SourceFiles/history/history.cpp
index 1f93f60f3..bfa188a2f 100644
--- a/Telegram/SourceFiles/history/history.cpp
+++ b/Telegram/SourceFiles/history/history.cpp
@@ -1495,6 +1495,9 @@ void History::addToSharedMedia(
 }
 
 std::optional<int> History::countUnread(MsgId upTo) const {
+	if (!folderKnown() || !loadedAtBottom()) {
+		return std::nullopt;
+	}
 	auto result = 0;
 	for (auto i = blocks.cend(), e = blocks.cbegin(); i != e;) {
 		--i;
@@ -1568,7 +1571,7 @@ void History::inboxRead(MsgId upTo, std::optional<int> stillUnread) {
 	if (unreadCount() > 0 && loadedAtBottom()) {
 		App::main()->historyToDown(this);
 	}
-	if (stillUnread) {
+	if (stillUnread.has_value() && folderKnown()) {
 		setUnreadCount(*stillUnread);
 	} else if (const auto still = countUnread(upTo)) {
 		setUnreadCount(*still);