librenms/librenms — pull request #292 by paulgear (2014-09-28 01:15:43+00:00)
Title: Fix MAC address change false positives

It seems at some point in the past $old_mac was an array, whereas now it's just a string. This bug was causing messages like this in the event log:

MAC change: 192.168.1.2 : 0::::: -> 00:11:22:33:44:55