From 804ed5115d50485fbe39709fb13eeead45713b30 Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Tue, 6 Oct 2020 18:20:34 +0200
Subject: [PATCH] Gui: [skip ci] fix appearance of TaskGroups when a style
 sheet is set

---
 src/Gui/Application.cpp | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/Gui/Application.cpp b/src/Gui/Application.cpp
index 21990b4cf2..36cdda7cf5 100644
--- a/src/Gui/Application.cpp
+++ b/src/Gui/Application.cpp
@@ -2345,8 +2345,14 @@ void Application::setStyleSheet(const QString& qssFile, bool tiledBackground)
 #endif
     }
 
-    if (mdi->style())
-        mdi->style()->unpolish(qApp);
+    // At startup time unpolish() mustn't be executed because otherwise the QSint widget
+    // appear incorrect due to an outdated cache.
+    // See https://doc.qt.io/qt-5/qstyle.html#unpolish-1
+    // See https://forum.freecadweb.org/viewtopic.php?f=17&t=50783
+    if (d->startingUp == false) {
+        if (mdi->style())
+            mdi->style()->unpolish(qApp);
+    }
 }
 
 void Application::checkForPreviousCrashes()