From bb016e14896bfe44fffafb8565e6e0f0f309a32e Mon Sep 17 00:00:00 2001
From: Ilya Fedin <fedin-ilja2010@ya.ru>
Date: Tue, 12 Jan 2021 19:35:32 +0400
Subject: [PATCH] Restore frameless hint on showing to workaround a bug in Qt

---
 Telegram/SourceFiles/window/window_title_qt.cpp | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/Telegram/SourceFiles/window/window_title_qt.cpp b/Telegram/SourceFiles/window/window_title_qt.cpp
index 2dbc133b6..2ee27b67f 100644
--- a/Telegram/SourceFiles/window/window_title_qt.cpp
+++ b/Telegram/SourceFiles/window/window_title_qt.cpp
@@ -306,6 +306,12 @@ void TitleWidgetQt::windowStateChanged(Qt::WindowState state) {
 void TitleWidgetQt::visibleChanged(bool visible) {
 	if (visible) {
 		updateWindowExtents();
+
+		// workaround a bug in Qt 5.12, works ok in Qt 5.15
+		// https://github.com/telegramdesktop/tdesktop/issues/10119
+		if (!_windowWasFrameless) {
+			toggleFramelessWindow(true);
+		}
 	}
 }