For dma-buf support we need a egl context.  The gtk x11 backend uses glx
contexts though.  We can't use the GtkGlArea widget on x11 because of
that, so use our own gtk-egl code instead.  wayland continues to use
the GtkGlArea widget.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 ui/gtk.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/ui/gtk.c b/ui/gtk.c
index 137667dd2d..d1101406d5 100644
--- a/ui/gtk.c
+++ b/ui/gtk.c
@@ -2440,12 +2440,15 @@ void early_gtk_display_init(DisplayOptions *opts)
     assert(opts->type == DISPLAY_TYPE_GTK);
     if (opts->has_gl && opts->gl) {
 #if defined(CONFIG_OPENGL)
-#if defined(CONFIG_GTK_GL)
-        gtk_use_gl_area = true;
-        gtk_gl_area_init();
-#else
-        gtk_egl_init();
+#if defined(CONFIG_GTK_GL) && defined(GDK_WINDOWING_WAYLAND)
+        if (GDK_IS_WAYLAND_DISPLAY(gdk_display_get_default())) {
+            gtk_use_gl_area = true;
+            gtk_gl_area_init();
+        }
 #endif
+        {
+            gtk_egl_init();
+        }
 #endif
     }
 
-- 
2.9.3