>>>> insert into <tablename> default values;
>> It bombs for me too, so I suspect you are right that I broke it when
>> I rearranged the analysis of INSERT. It's probably a minor oversight
>> someplace in there.
Nope, not a parser problem at all; rewriter brain damage. It's been
broken at least since 6.4, but only if you do INSERT ... DEFAULT VALUES
into a table that has no columns with default values, and only if you
have Asserts turned on (so the average user wouldn't see it anyway).
Fix is to dike out incorrect Assert...
regards, tom lane