From f1b0b60340e7b8d2cdf321dcf2da1d523e8e5579 Mon Sep 17 00:00:00 2001
From: John Preston <johnprestonmail@gmail.com>
Date: Thu, 21 Mar 2019 22:21:23 +0400
Subject: [PATCH] Fix possible crash in MainWindow destructor.

---
 .../platform/linux/specific_linux.cpp         | 32 +++++++++---------
 .../platform/win/main_window_win.cpp          | 33 +++++++++++--------
 2 files changed, 35 insertions(+), 30 deletions(-)

diff --git a/Telegram/SourceFiles/platform/linux/specific_linux.cpp b/Telegram/SourceFiles/platform/linux/specific_linux.cpp
index dba4a7357..31f32cc66 100644
--- a/Telegram/SourceFiles/platform/linux/specific_linux.cpp
+++ b/Telegram/SourceFiles/platform/linux/specific_linux.cpp
@@ -261,24 +261,22 @@ void finish() {
 }
 
 bool TranslucentWindowsSupported(QPoint globalPosition) {
-	if (auto app = static_cast<QGuiApplication*>(QCoreApplication::instance())) {
-		if (auto native = app->platformNativeInterface()) {
-			if (auto desktop = QApplication::desktop()) {
-				auto index = desktop->screenNumber(globalPosition);
-				auto screens = QGuiApplication::screens();
-				if (auto screen = (index >= 0 && index < screens.size()) ? screens[index] : QGuiApplication::primaryScreen()) {
-					if (native->nativeResourceForScreen(QByteArray("compositingEnabled"), screen)) {
-						return true;
-					}
-
-					static OrderedSet<int> WarnedAbout;
-					if (!WarnedAbout.contains(index)) {
-						WarnedAbout.insert(index);
-						LOG(("WARNING: Compositing is disabled for screen index %1 (for position %2,%3)").arg(index).arg(globalPosition.x()).arg(globalPosition.y()));
-					}
-				} else {
-					LOG(("WARNING: Could not get screen for index %1 (for position %2,%3)").arg(index).arg(globalPosition.x()).arg(globalPosition.y()));
+	if (const auto native = QGuiApplication::platformNativeInterface()) {
+		if (const auto desktop = QApplication::desktop()) {
+			const auto index = desktop->screenNumber(globalPosition);
+			const auto screens = QGuiApplication::screens();
+			if (const auto screen = (index >= 0 && index < screens.size()) ? screens[index] : QGuiApplication::primaryScreen()) {
+				if (native->nativeResourceForScreen(QByteArray("compositingEnabled"), screen)) {
+					return true;
 				}
+
+				static auto WarnedAbout = base::flat_set<int>();
+				if (!WarnedAbout.contains(index)) {
+					WarnedAbout.insert(index);
+					LOG(("WARNING: Compositing is disabled for screen index %1 (for position %2,%3)").arg(index).arg(globalPosition.x()).arg(globalPosition.y()));
+				}
+			} else {
+				LOG(("WARNING: Could not get screen for index %1 (for position %2,%3)").arg(index).arg(globalPosition.x()).arg(globalPosition.y()));
 			}
 		}
 	}
diff --git a/Telegram/SourceFiles/platform/win/main_window_win.cpp b/Telegram/SourceFiles/platform/win/main_window_win.cpp
index 36d19357e..ffdd13635 100644
--- a/Telegram/SourceFiles/platform/win/main_window_win.cpp
+++ b/Telegram/SourceFiles/platform/win/main_window_win.cpp
@@ -767,12 +767,17 @@ void MainWindow::updateIconCounters() {
 }
 
 void MainWindow::initHook() {
-	auto platformInterface = QGuiApplication::platformNativeInterface();
-	ps_hWnd = static_cast<HWND>(platformInterface->nativeResourceForWindow(QByteArrayLiteral("handle"), windowHandle()));
+	if (const auto native = QGuiApplication::platformNativeInterface()) {
+		ps_hWnd = static_cast<HWND>(native->nativeResourceForWindow(
+			QByteArrayLiteral("handle"),
+			windowHandle()));
+	}
+	if (!ps_hWnd) {
+		return;
+	}
 
-	if (!ps_hWnd) return;
-
-	handleSessionNotification = (Dlls::WTSRegisterSessionNotification != nullptr) && (Dlls::WTSUnRegisterSessionNotification != nullptr);
+	handleSessionNotification = (Dlls::WTSRegisterSessionNotification != nullptr)
+		&& (Dlls::WTSUnRegisterSessionNotification != nullptr);
 	if (handleSessionNotification) {
 		Dlls::WTSRegisterSessionNotification(ps_hWnd, NOTIFY_FOR_THIS_SESSION);
 	}
@@ -914,8 +919,12 @@ void MainWindow::psUpdateMargins() {
 		_deltaLeft = _deltaTop = _deltaRight = _deltaBottom = 0;
 	}
 
-	QPlatformNativeInterface *i = QGuiApplication::platformNativeInterface();
-	i->setWindowProperty(windowHandle()->handle(), qsl("WindowsCustomMargins"), QVariant::fromValue<QMargins>(margins));
+	if (const auto native = QGuiApplication::platformNativeInterface()) {
+		native->setWindowProperty(
+			windowHandle()->handle(),
+			qsl("WindowsCustomMargins"),
+			QVariant::fromValue<QMargins>(margins));
+	}
 	if (!_themeInited) {
 		_themeInited = true;
 		if (QSysInfo::WindowsVersion < QSysInfo::WV_WINDOWS8) {
@@ -953,13 +962,11 @@ void MainWindow::psDestroyIcons() {
 
 MainWindow::~MainWindow() {
 	if (handleSessionNotification) {
-		QPlatformNativeInterface *i = QGuiApplication::platformNativeInterface();
-		if (HWND hWnd = static_cast<HWND>(i->nativeResourceForWindow(QByteArrayLiteral("handle"), windowHandle()))) {
-			Dlls::WTSUnRegisterSessionNotification(hWnd);
-		}
+		Dlls::WTSUnRegisterSessionNotification(ps_hWnd);
+	}
+	if (taskbarList) {
+		taskbarList.Reset();
 	}
-
-	if (taskbarList) taskbarList.Reset();
 
 	_shadowsWorking = false;
 	if (ps_menu) DestroyMenu(ps_menu);