Workaround render glitches on new MacBooks.

For unknown reason large windows have bad render glitches in High Sierra.
Forcing of OpenGL composition (by adding a fake child QOpenGLWidget) fixes it.

Telegram/SourceFiles/messenger.cpp

@@ -129,7 +129,6 @@ Messenger::Messenger() : QObject()
 	QMimeDatabase().mimeTypeForName(qsl("text/plain"));
 
 	_window = std::make_unique<MainWindow>();
-	_window->createWinId();
 	_window->init();
 
 	auto currentGeometry = _window->geometry();

Telegram/SourceFiles/platform/mac/main_window_mac.mm

@@ -216,6 +216,8 @@ MainWindow::Private::~Private() {
 
 MainWindow::MainWindow()
 : _private(std::make_unique<Private>(this)) {
+	auto forceOpenGL = std::make_unique<QOpenGLWidget>(this);
+
 	trayImg = st::macTrayIcon.instance(QColor(0, 0, 0, 180), dbisOne);
 	trayImgSel = st::macTrayIcon.instance(QColor(255, 255, 255), dbisOne);
 

Telegram/SourceFiles/window/main_window.cpp

@@ -135,6 +135,9 @@ void MainWindow::updateWindowIcon() {
 }
 
 void MainWindow::init() {
+	Expects(!windowHandle());
+	createWinId();
+
 	initHook();
 	updateWindowIcon();