Index: lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20190721.sql
===================================================================
diff -u -r881a5b96d6e82cd465e71a1041dc4de99b52e3e8 -r7f49e520871e7cd1f584717ca92993a48bfa48b7
--- lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20190721.sql	(.../patch20190721.sql)	(revision 881a5b96d6e82cd465e71a1041dc4de99b52e3e8)
+++ lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20190721.sql	(.../patch20190721.sql)	(revision 7f49e520871e7cd1f584717ca92993a48bfa48b7)
@@ -2,6 +2,7 @@
 BEGIN
     DECLARE $start, $end INT DEFAULT 1;
     DECLARE $tag CHAR(3);
+    IF ($str IS NULL) THEN RETURN NULL; END IF;
     main: LOOP
         SET $start = LOCATE("<", $str, $start);
         IF (NOT $start) THEN RETURN $str; END IF;