Re: [HACKERS] questionable code in heap_formtuple()] - Mailing list pgsql-hackers

> > > around line 812 in access/common/heaptuple.c:
> > >
> > >     len = sizeof *tuple - sizeof tuple->t_bits;
> > >
> > > This seems questionable for me.
>
>
> > > I think more acculate way to calculate the offset is:
> > >
> > >     len = (char *)&tuple->t_bits[0] - (char *)tuple;
>
> OK, now I am more confused.  Doesn't this work:
>
>     len = sizeof(HeapTupleData) - offsetof(HeapTupleData.t_bits);
>
> while your solution is finding the size of the area before t_bits?

OK, I finally get it.  I was thinking HeapTupleData had the tuple data
in the structure, while obviously it does not.

Sometimes there is no HeapTuple to get the size of at the point you need
it, so I have applied a patch to do

    len = offsetof(HeapTupleData.t_bits);

which should fix the obvious problem Tatsuo Ishii found.  Does that fix
anything, index people?

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