diff -ru docbook-utils-0.6.11/frontends/docbook.in docbook-utils-0.6.11.patch/frontends/docbook.in
--- docbook-utils-0.6.11/frontends/docbook.in	Thu Jun 27 06:28:20 2002
+++ docbook-utils-0.6.11.patch/frontends/docbook.in	Thu Aug 22 13:04:10 2002
@@ -25,7 +25,7 @@
 	    break
 	  fi
 	done
-	if [ -z "SGML_CATALOG" ]
+	if [ -z "$SGML_CATALOG" ]
 	then
 	  if [ "${SGML_XML}" != "sgml" ]
 	  then SGML_CATALOG=${SGML_CATALOGS_DIR}/${SGML_XML}-docbook.cat