woothemes/woocommerce — pull request #6648 by SiR-DanieL (2014-10-29 14:08:39+00:00)
Title: Added cancelled order admin email

Added the cancelled order admin email notification. Useful when an order has been cancelled automatically because the customer does not pay for it.

It's triggered when the order status changes from

on-hold -> cancelled
pending -> cancelled

i was not sure if i should add it also when the status changes from failed. What do you think @mikejolley ?