QOffscreenContext becomes version 2.0 when using EGL

Hi,

I have an application that creates a window with some OpenGL contexts, and then a bunch of offscreen surfaces and contexts (sharing with the former) to be able to hand them to worker threads.

I ask for OpenGL 4.5 core, same as for the global context:

 QSurfaceFormat fmt;
 fmt.setDepthBufferSize(0);
 fmt.setStencilBufferSize(0);
 fmt.setProfile(QSurfaceFormat::CoreProfile);
 fmt.setMajorVersion(4);
 fmt.setMinorVersion(5);
 fmt.setSwapInterval(0);
 assert(QThread::currentThread() == QCoreApplication::instance()->thread());
 QOffscreenSurface *surface = new QOffscreenSurface;
 surface->setFormat(fmt);
 surface->create();

However, if I use EGL (QT_XCB_GL_INTEGRATION=xcb_egl), which I need to for some zerocopy functionality between OpenGL and VA-API, the offscreen surfaces come back as 2.0 compatibility, instead of 4.5 core. So now you have a 4.5 core and a 2.0 compatibility context, sharing shaders. This triggers Mesa bug #110872 (which I guess you could argue isn't a Mesa bug at all), which makes my application crash.