init: forward wayland display only if it is set

Signed-off-by: Luca Di Maio <luca.dimaio1@gmail.com>

distrobox-init

@@ -1789,6 +1789,10 @@ if [ -z "\$XAUTHLOCALHOSTNAME" ]; then
     export XAUTHLOCALHOSTNAME="\$(host-spawn sh -c "printf "%s" \\\$XAUTHLOCALHOSTNAME")"
     [ -z "\$XAUTHLOCALHOSTNAME" ] && unset XAUTHLOCALHOSTNAME
 fi
+if [ -z "\$WAYLAND_DISPLAY" ]; then
+    export WAYLAND_DISPLAY="\$(host-spawn sh -c "printf "%s" \\\$WAYLAND_DISPLAY")"
+    [ -z "\$WAYLAND_DISPLAY" ] && unset WAYLAND_DISPLAY
+fi
 
 # This will ensure a default prompt for a container, this will be remineshent of
 # toolbx prompt: https://github.com/containers/toolbox/blob/main/profile.d/toolbox.sh#L47
@@ -1829,6 +1833,10 @@ if test -z \$XAUTHLOCALHOSTNAME
     set -gx XAUTHLOCALHOSTNAME (host-spawn sh -c "printf "%s" \\\$XAUTHLOCALHOSTNAME")
     test -z \$XAUTHLOCALHOSTNAME ; and set -e XAUTHLOCALHOSTNAME
 end
+if test -z \$WAYLAND_DISPLAY
+    set -gx WAYLAND_DISPLAY (host-spawn sh -c "printf "%s" \\\$WAYLAND_DISPLAY")
+    test -z \$WAYLAND_DISPLAY ; and set -e WAYLAND_DISPLAY
+end
 
 # This will ensure we have a first-shell password setup for an user if needed.
 # We're going to use this later in case of rootful containers