[Interest] Strange issue with Qt, OpenGL and remote desktop

Rainer Wiesenfarth rainer_wiesenfarth at trimble.com
Fri Oct 25 08:56:23 CEST 2019

On Thu, Oct 24, 2019 at 10:23 PM Giuseppe D'Angelo via Interest <
interest at qt-project.org> wrote:

> Il 24/10/19 17:57, Rainer Wiesenfarth ha scritto:
> > We ran into a reproducible crash that is restricted to a certain
> > scenario. The crash occurs in QGlContextPrivate::syncGlState() when
> > trying to call glDisableVertexAttribArray(). It seems the function
> > pointer is not available. However, there are some other factors involved:
> Very wild guess, maybe remote desktop is somehow issuing a GL context
> reset, and the code in question is not prepared to handle it?
> (Are we talking about QGL* classes here or QOpenGL* classes?)

This is (still) QGL..., we have not yet switched to the QOpenGL... classes.

Remote desktop is definitely involved in some way, as its Windows 10
version supports OpenGL > 1.1. Probably the graphics driver also, as the
issue is related to (older) Nvidia GTX boards.

In the meantime we ran the OpenGL Extensions Viewer (version 6.0.5) both
locally on one of the affected machines as well as via RDP. Over RDP, it
also crashes, during "Querying properties - Forwarding context 4.1" or "...
4.3". So, the root cause seems to be unrelated to Qt (I assumed that
earlier), but it would be nice if we could get our application / Qt 5.12.x
to cure the symptoms, as at least Qt 5.6.2 did not trigger the crash...

Cheers, Rainer

Software Engineer | Trimble Imaging Division
Rotebühlstraße 81 | 70178 Stuttgart | Germany
Office +49 711 22881 0 | Fax +49 711 22881 11
http://www.trimble.com/imaging/ | http://www.inpho.de/

Trimble Germany GmbH, Am Prime Parc 11, 65479 Raunheim
Eingetragen beim Amtsgericht Darmstadt unter HRB 83893,
Geschäftsführer: Dr. Frank Heimberg, Jürgen Kesper
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.qt-project.org/pipermail/interest/attachments/20191025/179895d8/attachment.html>

More information about the Interest mailing list