findoprnd(ITEM *ptr, int32 *pos)
{
	/* since this function recurses, it could be driven to stack overflow. */
	check_stack_depth();

	if (ptr[*pos].type == VAL || ptr[*pos].type == VALTRUE)
	{
		ptr[*pos].left = 0;
		(*pos)++;
	}
	else if (ptr[*pos].val == (int32) '!')
	{
		ptr[*pos].left = 1;
		(*pos)++;
		findoprnd(ptr, pos);
	}
	else
	{
		ITEM	   *curitem = &ptr[*pos];
		int32		tmp = *pos;

		(*pos)++;
		findoprnd(ptr, pos);
		curitem->left = *pos - tmp;
		findoprnd(ptr, pos);
	}
}
Weaknesses in this category are related to improper calculation or conversion of numbers.