You must have modified your lib-common.php then, since COM_makeList only starts in line 4797.
Anyway, the problem is with whatever is calling that function. Do you have some sort of dynamic block on your site that displays items in a list? Looks like occasionally, it's calling COM_makeList with an empty data set.
The function should certainly be more fault tolerant, but the real problem is the calling entity.
bye, Dirk