From cff5360280c763b76ef70e42a2d66a1a755bcb35 Mon Sep 17 00:00:00 2001
From: Bruno de Oliveira Abinader <bruno@mapbox.com>
Date: Mon, 24 Oct 2016 18:57:39 +0300
Subject: [PATCH] [qt] Fix macOS Qt demo app with Qt4.x

---
 platform/qt/app/mapwindow.cpp | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/platform/qt/app/mapwindow.cpp b/platform/qt/app/mapwindow.cpp
index ca73b0a8d..0cce6caae 100644
--- a/platform/qt/app/mapwindow.cpp
+++ b/platform/qt/app/mapwindow.cpp
@@ -297,5 +297,15 @@ void MapWindow::resizeGL(int w, int h)
 void MapWindow::paintGL()
 {
     m_frameDraws++;
+
+#if QT_VERSION < 0x050400 && defined(__APPLE__)
+    // XXX GL framebuffer is valid only after first attempt of painting on
+    // older versions of Qt on macOS.
+    // See https://bugreports.qt.io/browse/QTBUG-36802 for details.
+    static bool first = true;
+    if (!first) m_map.render();
+    first = false;
+#else
     m_map.render();
+#endif
 }