Hi,
JIT slot_compile_deform assumes there's at least 'natts' in TupleDesc, eg
/*
* Iterate over each attribute that needs to be deformed, build code to
* deform it.
*/
for (attnum = 0; attnum < natts; attnum++)
{
Form_pg_attribute att = TupleDescAttr(desc, attnum);
but a new TupleDesc has no attribute and the caller only tests
TupleDesc is not null.