[gnome-settings-daemon/benzea/test-display-env] tests: Unset display environment variables

[Benjamin Berg <bberg src gnome org>]

commit 82356e0f9db9de306a1f2c2864755727c6383b96
Author: Benjamin Berg <bberg redhat com>
Date:   Wed Nov 25 18:11:31 2020 +0100

    tests: Unset display environment variables
    
    The environment variables were not correctly cleared. Fix this and also
    make sure that we don't have the GNOME_SETUP_DISPLAY environment
    variable leaking in from the outside.

 tests/x11session.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/tests/x11session.py b/tests/x11session.py
index ff2d389c..7fb0b834 100644
--- a/tests/x11session.py
+++ b/tests/x11session.py
@@ -94,7 +94,10 @@ class X11SessionTestCase(DBusTestCase):
         klass.X_display = display
         # Export information into our environment for tests to use
         os.environ['DISPLAY'] = ":%d" % klass.X_display
-        os.environ['WAYLAND'] = ''
+        if 'GNOME_SETUP_DISPLAY' in os.environ:
+            del os.environ['GNOME_SETUP_DISPLAY']
+        if 'WAYLAND_DISPLAY' in os.environ:
+            del os.environ['WAYLAND_DISPLAY']
 
         # Server should still be up and running at this point
         assert klass.xorg.poll() is None