liveinst: Allow running as a Wayland-native application

As long as we have the path to the Wayland socket, we can run
Anaconda as a Wayland-native application.

data/liveinst/liveinst

@@ -20,11 +20,24 @@
 
 BACKEND_READY_FLAG=/run/anaconda/backend_ready
 
+WAYLAND_DISPLAY_SOCKET=/tmp/anaconda-wldisplay
+
+# Detect and save the wayland socket before re-exec
+if [ -n "$WAYLAND_DISPLAY" ]; then
+    if [ -e "$WAYLAND_DISPLAY_SOCKET" ]; then
+        rm -f "${WAYLAND_DISPLAY_SOCKET}"
+    fi
+    touch "${WAYLAND_DISPLAY_SOCKET}"
+    echo "${XDG_RUNTIME_DIR}/${WAYLAND_DISPLAY}" > ${WAYLAND_DISPLAY_SOCKET}
+fi
+
 # The command needs to be run with root privileges, so if it was started
 # unprivileged, restart running as root.
 if [ "$(id -u)" -ne 0 ]; then
-    xhost +si:localuser:root
-    unset XAUTHORITY
+    if [ -z "$WAYLAND_DISPLAY" ]; then
+        xhost +si:localuser:root
+        unset XAUTHORITY
+    fi
     pkexec "$0" "$@"
 fi
 
@@ -33,6 +46,11 @@ if [ -z "$DBUS_SESSION_BUS_ADDRESS" ]; then
     export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/${PKEXEC_UID}/bus
 fi
 
+# pkexec clears WAYLAND_DISPLAY from environment
+if [ -z "$WAYLAND_DISPLAY" ] && [ -e "$WAYLAND_DISPLAY_SOCKET" ]; then
+    export WAYLAND_DISPLAY=$(cat "${WAYLAND_DISPLAY_SOCKET}")
+fi
+
 # Allow running another command in the place of anaconda, but in this same
 # environment.  This allows storage testing to make use of all the module
 # loading and lvm control in this file, too.
@@ -170,8 +188,10 @@ start_anaconda() {
     $ANACONDA "$@"
 }
 
-# Force the X11 backend since sudo and wayland do not mix
-export GDK_BACKEND=x11
+# If no wayland socket is set, force x11 so that it loads correctly
+if [ -z "$WAYLAND_DISPLAY" ]; then
+    export GDK_BACKEND=x11
+fi
 
 if [ -x /usr/bin/udisks ]; then
     /usr/bin/udisks --inhibit -- start_anaconda "$@"