[gtk/ebassi/egl-x11] x11: Always fall back to GLX on NVIDIA

[Emmanuele Bassi <ebassi src gnome org>]

commit 118e6241c57c80d72a84b956dbb7047e9ecb1db3
Author: Emmanuele Bassi <ebassi gnome org>
Date:   Mon May 10 20:37:13 2021 +0100

    x11: Always fall back to GLX on NVIDIA
    
    At least until we can guarantee that EGL-X11 works fine there.

 gdk/x11/gdkglcontext-egl.c | 9 +++++++++
 1 file changed, 9 insertions(+)
---
diff --git a/gdk/x11/gdkglcontext-egl.c b/gdk/x11/gdkglcontext-egl.c
index a2b195fc77..1836f19057 100644
--- a/gdk/x11/gdkglcontext-egl.c
+++ b/gdk/x11/gdkglcontext-egl.c
@@ -572,6 +572,15 @@ gdk_x11_screen_init_egl (GdkX11Screen *screen)
   if (!eglInitialize (edpy, &major, &minor))
     return FALSE;
 
+  /* While NVIDIA might support EGL, it might very well not support
+   * all the EGL subset we rely on; we should be looking at more
+   * EGL extensions, but for the time being, this is a blanket
+   * fallback to GLX
+   */
+  const char *vendor = eglQueryString (edpy, EGL_VENDOR);
+  if (g_strcmp0 (vendor, "NVIDIA Corporation") == 0)
+    return FALSE;
+
   display_x11->have_egl = TRUE;
   display_x11->egl_version = epoxy_egl_version (dpy);