From 63a88d0d26eff44549be233518c8005356139f7a Mon Sep 17 00:00:00 2001
From: Allan Sandfeld Jensen <allan.jensen@qt.io>
Date: Mon, 18 May 2020 13:21:47 +0200
Subject: [PATCH] Allow multithreaded opengl to be disabled

Pick-to: 5.15
Change-Id: I5bffb6d6844c19adc575d86d5f9846af344a8679
Reviewed-by: Laszlo Agocs <laszlo.agocs@qt.io>
---
 .../platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
index 0fd421e925..ea9db10858 100644
--- a/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
+++ b/src/plugins/platforms/xcb/gl_integrations/xcb_glx/qglxintegration.cpp
@@ -786,6 +786,10 @@ void QGLXContext::queryDummyContext()
         }
     }
 
+    static bool nomultithread = qEnvironmentVariableIsSet("QT_XCB_NO_THREADED_OPENGL");
+    if (nomultithread)
+        m_supportsThreading = false;
+
     context.doneCurrent();
     if (oldContext && oldSurface)
         oldContext->makeCurrent(oldSurface);