From 4e1154dfd128cbada65e9ea08ee274cdeafc4c53 Mon Sep 17 00:00:00 2001
From: Hennadii Stepanov <32963518+hebasto@users.noreply.github.com>
Date: Thu, 7 Jan 2021 23:04:56 +0200
Subject: [PATCH] qt: Use "fusion" style on macOS Big Sur with old Qt

The "macintosh" style is broken on macOS Big Sur at least for Qt 5.9.8.
---
 src/qt/bitcoin.cpp | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index 8efb0e35d0..d6d5ba6968 100644
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -51,6 +51,7 @@
 #include <QThread>
 #include <QTimer>
 #include <QTranslator>
+#include <QtGlobal>
 
 #if defined(QT_STATICPLUGIN)
 #include <QtPlugin>
@@ -466,6 +467,13 @@ int GuiMain(int argc, char* argv[])
     QCoreApplication::setAttribute(Qt::AA_EnableHighDpiScaling);
 #endif
 
+#if (QT_VERSION <= QT_VERSION_CHECK(5, 9, 8)) && defined(Q_OS_MACOS)
+    const auto os_name = QSysInfo::prettyProductName();
+    if (os_name.startsWith("macOS 11") || os_name.startsWith("macOS 10.16")) {
+        QApplication::setStyle("fusion");
+    }
+#endif
+
     BitcoinApplication app;
 
     /// 2. Parse command-line options. We do this after qt in order to show an error if there are problems parsing these