From 6bd530182879337ab1ba50769e465392f23391ae Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Fri, 9 Mar 2018 14:44:42 +0300
Subject: [PATCH] Fix crash when accessing a deleted item view.

---
 .../SourceFiles/data/data_peer_values.cpp     |  4 ++--
 Telegram/SourceFiles/data/data_session.cpp    |  8 +++++++
 Telegram/SourceFiles/data/data_session.h      |  3 +++
 .../history/history_inner_widget.cpp          | 22 ++++++++++++++++---
 .../history/history_inner_widget.h            |  1 +
 Telegram/SourceFiles/history/history_item.cpp |  1 +
 6 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/Telegram/SourceFiles/data/data_peer_values.cpp b/Telegram/SourceFiles/data/data_peer_values.cpp
index 8d55136e4..2f3e849a8 100644
--- a/Telegram/SourceFiles/data/data_peer_values.cpp
+++ b/Telegram/SourceFiles/data/data_peer_values.cpp
@@ -21,7 +21,7 @@ int OnlinePhraseChangeInSeconds(TimeId online, TimeId now) {
 		if (-online > now) {
 			return (-online - now);
 		}
-		return std::numeric_limits<int32>::max();
+		return std::numeric_limits<TimeId>::max();
 	}
 	if (online > now) {
 		return online - now;
@@ -36,7 +36,7 @@ int OnlinePhraseChangeInSeconds(TimeId online, TimeId now) {
 	}
 	const auto nowFull = ParseDateTime(now);
 	const auto tomorrow = QDateTime(nowFull.date().addDays(1));
-	return static_cast<int32>(nowFull.secsTo(tomorrow));
+	return std::max(static_cast<TimeId>(nowFull.secsTo(tomorrow)), 0);
 }
 
 base::optional<QString> OnlineTextSpecial(not_null<UserData*> user) {
diff --git a/Telegram/SourceFiles/data/data_session.cpp b/Telegram/SourceFiles/data/data_session.cpp
index 5f670542a..2a42fadd2 100644
--- a/Telegram/SourceFiles/data/data_session.cpp
+++ b/Telegram/SourceFiles/data/data_session.cpp
@@ -273,6 +273,14 @@ rpl::producer<not_null<const HistoryItem*>> Session::itemRemoved() const {
 	return _itemRemoved.events();
 }
 
+void Session::notifyViewRemoved(not_null<const ViewElement*> view) {
+	_viewRemoved.fire_copy(view);
+}
+
+rpl::producer<not_null<const ViewElement*>> Session::viewRemoved() const {
+	return _viewRemoved.events();
+}
+
 void Session::notifyHistoryUnloaded(not_null<const History*> history) {
 	_historyUnloaded.fire_copy(history);
 }
diff --git a/Telegram/SourceFiles/data/data_session.h b/Telegram/SourceFiles/data/data_session.h
index 58e88a4ca..11ce8b635 100644
--- a/Telegram/SourceFiles/data/data_session.h
+++ b/Telegram/SourceFiles/data/data_session.h
@@ -87,6 +87,8 @@ public:
 
 	void notifyItemRemoved(not_null<const HistoryItem*> item);
 	[[nodiscard]] rpl::producer<not_null<const HistoryItem*>> itemRemoved() const;
+	void notifyViewRemoved(not_null<const ViewElement*> view);
+	[[nodiscard]] rpl::producer<not_null<const ViewElement*>> viewRemoved() const;
 	void notifyHistoryCleared(not_null<const History*> history);
 	[[nodiscard]] rpl::producer<not_null<const History*>> historyCleared() const;
 	void notifyHistoryChangeDelayed(not_null<History*> history);
@@ -468,6 +470,7 @@ private:
 	rpl::event_stream<not_null<HistoryItem*>> _itemViewRefreshRequest;
 	rpl::event_stream<not_null<HistoryItem*>> _animationPlayInlineRequest;
 	rpl::event_stream<not_null<const HistoryItem*>> _itemRemoved;
+	rpl::event_stream<not_null<const ViewElement*>> _viewRemoved;
 	rpl::event_stream<not_null<const History*>> _historyUnloaded;
 	rpl::event_stream<not_null<const History*>> _historyCleared;
 	base::flat_set<not_null<History*>> _historiesChanged;
diff --git a/Telegram/SourceFiles/history/history_inner_widget.cpp b/Telegram/SourceFiles/history/history_inner_widget.cpp
index 0d7b8d1c1..3c0068a8f 100644
--- a/Telegram/SourceFiles/history/history_inner_widget.cpp
+++ b/Telegram/SourceFiles/history/history_inner_widget.cpp
@@ -139,10 +139,14 @@ HistoryInner::HistoryInner(
 	) | rpl::start_with_next(
 		[this](auto item) { itemRemoved(item); },
 		lifetime());
+	Auth().data().viewRemoved(
+	) | rpl::start_with_next(
+		[this](auto view) { viewRemoved(view); },
+		lifetime());
 	Auth().data().itemViewRefreshRequest(
-	) | rpl::start_with_next([this](auto item) {
-		refreshView(item);
-	}, lifetime());
+	) | rpl::start_with_next(
+		[this](auto item) { refreshView(item); },
+		lifetime());
 	rpl::merge(
 		Auth().data().historyUnloaded(),
 		Auth().data().historyCleared()
@@ -1222,6 +1226,18 @@ void HistoryInner::itemRemoved(not_null<const HistoryItem*> item) {
 	mouseActionUpdate();
 }
 
+void HistoryInner::viewRemoved(not_null<const Element*> view) {
+	if (_dragSelFrom == view) {
+		_dragSelFrom = nullptr;
+	}
+	if (_dragSelTo == view) {
+		_dragSelTo = nullptr;
+	}
+	if (_scrollDateLastItem == view) {
+		_scrollDateLastItem = nullptr;
+	}
+}
+
 void HistoryInner::refreshView(not_null<HistoryItem*> item) {
 	const auto dragSelFrom = (_dragSelFrom && _dragSelFrom->data() == item);
 	const auto dragSelTo = (_dragSelTo && _dragSelTo->data() == item);
diff --git a/Telegram/SourceFiles/history/history_inner_widget.h b/Telegram/SourceFiles/history/history_inner_widget.h
index d430769d4..e8eec987d 100644
--- a/Telegram/SourceFiles/history/history_inner_widget.h
+++ b/Telegram/SourceFiles/history/history_inner_widget.h
@@ -214,6 +214,7 @@ private:
 	void toggleFavedSticker(not_null<DocumentData*> document);
 
 	void itemRemoved(not_null<const HistoryItem*> item);
+	void viewRemoved(not_null<const Element*> view);
 	void refreshView(not_null<HistoryItem*> item);
 
 	void touchResetSpeed();
diff --git a/Telegram/SourceFiles/history/history_item.cpp b/Telegram/SourceFiles/history/history_item.cpp
index 71014e4e6..39f6d5da7 100644
--- a/Telegram/SourceFiles/history/history_item.cpp
+++ b/Telegram/SourceFiles/history/history_item.cpp
@@ -268,6 +268,7 @@ void HistoryItem::refreshMainView() {
 void HistoryItem::removeMainView() {
 	if (const auto view = mainView()) {
 		Auth().data().notifyHistoryChangeDelayed(_history);
+		Auth().data().notifyViewRemoved(view);
 		view->removeFromBlock();
 	}
 }