[Hsqldb-user] Unable to generate script on shutdown with simple constraint

[Daniel C. <dc...@cy...>]

Creating the following tables and constraints results in shutdown failure
and exceptions on startup, both when generating the scripts:

create table T1 ( FK NUMERIC not null ); 
create table T2 ( ID NUMERIC not null, constraint T2_PK primary key (ID) ); 
alter table T1 add constraint T1_FK foreign key (FK) references T2 (ID); 

Stack trace:

at org.hsqldb.Trace.printStack(Trace.java:565)
at org.hsqldb.Trace.doAssert(Trace.java:364)
at org.hsqldb.Table.getIndexRoots(Table.java:714)
at org.hsqldb.DatabaseScript.getIndexRootsDDL(DatabaseScript.java:371)
at org.hsqldb.DatabaseScript.getScript(DatabaseScript.java:215)
at org.hsqldb.Database.getScript(Database.java:748)
at org.hsqldb.Log.scriptToFile(Log.java:557)
at org.hsqldb.Log.writeScript(Log.java:941)
at org.hsqldb.Log.close(Log.java:381)
at org.hsqldb.Database$Logger.closeLog(Database.java:2667)
at org.hsqldb.Database.close(Database.java:2300)
at org.hsqldb.Database.processShutdown(Database.java:2354)
at org.hsqldb.Database.execute(Database.java:519)
at org.hsqldb.ServerConnection.run(ServerConnection.java:198)
at java.lang.Thread.run(Thread.java:536)

Is this a defect, or something obvious that I missing because I am a newb?

Tx!

Dan.