[gnome-desktop/wip/hadess/fix-wallclock-reftest: 1/2] tests: Require x11 for the wallclock-reftest

[Bastien Nocera <hadess src gnome org>]

commit 3b2086dad437b19afaac0b83c059531aadc1c72f
Author: Bastien Nocera <hadess hadess net>
Date:   Tue Apr 7 10:54:55 2020 +0200

    tests: Require x11 for the wallclock-reftest
    
    It's broken for every other backend.

 tests/wallclock-reftest.c | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/tests/wallclock-reftest.c b/tests/wallclock-reftest.c
index 0a7e812d..9c90eeca 100644
--- a/tests/wallclock-reftest.c
+++ b/tests/wallclock-reftest.c
@@ -586,6 +586,9 @@ main (int argc, char **argv)
   unsetenv("LC_ALL");
   unsetenv("LC_TIME");
 
+  /* gdk_cairo_set_source_window() doesn't work with anything but X11 */
+  gdk_set_allowed_backends ("x11");
+
   /* I don't want to fight fuzzy scaling algorithms in GPUs,
    * so unless you explicitly set it to something else, we
    * will use Cairo's image surface.