Re: BUG #18135: Incorrect memory access occurs when attaching a partition with an index

PG Bug reporting form <noreply(at)postgresql(dot)org> writes:
> The function CompareIndexInfo() contains the code:
> /* ignore expressions at this stage */
> if ((info1->ii_IndexAttrNumbers[i] != InvalidAttrNumber) &&
> (attmap->attnums[info2->ii_IndexAttrNumbers[i] - 1] !=
> info1->ii_IndexAttrNumbers[i]))
> return false;

> where info1->ii_IndexAttrNumbers[i] is checked for InvalidAttrNumber
> (i. e. it's not an expression), but info2->ii_IndexAttrNumbers[i] is not.

Agreed, that's pretty broken, and it's not just that it risks an
invalid access. I don't think this reliably rejects cases where
one index has an expression and the other doesn't. Even if it does
work, it's way too complicated to convince oneself that that's
rejected. I think for clarity we should code it as attached.

regards, tom lane