Hi,
No, the lin 129 is correct. $query->direction is supposed to be an array.
The problem is that the function is called and that variable is already not an array.
So it means that something else somewhere set it as a string and it shouldn't. I looked around to try to find the cause and this line 136 was definitely not correct so I thought it might be coming from it.
Change also the line:
to:
in the file administrator/components/com_hikashop/classes/massaction.php and that will fix the problem for good.