ALTER TABLE reporting 0 records affected in 5.6

Hi,
We are in the process of moving from Percona 5.5 to 5.6 and I just noticed a difference between the two I was hoping someone could shed some light on. When I execute an ALTER TABLE command in 5.5 it says “Query OK, 52990 rows affected”, but when I run the same command on the same data in 5.6 I get “Query OK, 0 rows affected”.

There are no warnings, or errors, and the change does happen as expected, it just says 0 rows were affected.

I know in 5.6 they have changed the functionality of ALTER TABLE, such that it doesn’t block near as much, but is this why it says there are 0 rows?