[gnome-settings-daemon/benzea/only-use-non-empty-setup-display] common: Only use GNOME_SETUP_DISPLAY if it is not empty

[Benjamin Berg <bberg src gnome org>]

commit 31078dc8188c987c91615d31fed2d9b78ed09e9e
Author: Benjamin Berg <bberg redhat com>
Date:   Sat Mar 21 16:17:09 2020 +0100

    common: Only use GNOME_SETUP_DISPLAY if it is not empty
    
    This means that setting it to an empty value will still make g-s-d
    ignore it.

 plugins/common/daemon-skeleton-gtk.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/plugins/common/daemon-skeleton-gtk.h b/plugins/common/daemon-skeleton-gtk.h
index f39fd5d6..596281df 100644
--- a/plugins/common/daemon-skeleton-gtk.h
+++ b/plugins/common/daemon-skeleton-gtk.h
@@ -224,7 +224,7 @@ main (int argc, char **argv)
 #ifdef GDK_BACKEND
        {
                const gchar *setup_display = getenv ("GNOME_SETUP_DISPLAY");
-               if (setup_display)
+               if (setup_display && *setup_display != '\0')
                        g_setenv ("DISPLAY", setup_display, TRUE);
        }