poly_contained(PG_FUNCTION_ARGS)
{
	Datum		polya = PG_GETARG_DATUM(0);
	Datum		polyb = PG_GETARG_DATUM(1);

	/* Just switch the arguments and pass it off to poly_contain */
	PG_RETURN_DATUM(DirectFunctionCall2(poly_contain, polyb, polya));
}

This weakness involves numeric computation errors, such as integer overflows, underflows, or precision losses, which can lead to miscalculations and exploitable behaviors in software.