The sqlite_rename_parent() SQL function is an undocumented function used as
part of the implementation of ALTER TABLE.  This function should never be
access by an application.  But if an application does invoke the function and
gives it a NULL parameter in the 1st or 2nd argument, a crash might result.

<blockquote><verbatim>
SELECT sqlite_rename_parent(NULL,1,1);


The problem appears to have existed since ALTER TABLE was first enhanced to
be able to deal with foreign key constraints, by check-in [b4a10c39e726dc190]
on 2009-09-26 for SQLite version 3.6.19.