diff -aur plymouth.src/scripts/plymouth-set-default-theme.in plymouth.patch/scripts/plymouth-set-default-theme.in
--- plymouth.src/scripts/plymouth-set-default-theme.in       2014-02-20 19:38:13.319427393 +1100
+++ plymouth.patch/scripts/plymouth-set-default-theme.in      2014-02-20 19:54:13.035553244 +1100
@@ -173,7 +173,10 @@
         exit $?
 fi
 
-if [ ! -e ${PLYMOUTH_DATADIR}/plymouth/themes/${THEME_NAME}/${THEME_NAME}.plymouth ]; then
+if [ -z ${THEME_NAME} ]; then
+        echo "Please specify a theme name"
+        exit 1
+elif [ ! -e ${PLYMOUTH_DATADIR}/plymouth/themes/${THEME_NAME}/${THEME_NAME}.plymouth ]; then
         echo "${PLYMOUTH_DATADIR}/plymouth/themes/${THEME_NAME}/${THEME_NAME}.plymouth does not exist" >&2
         exit 1
 fi