As usual, seconds after sending a review request I somewhere find another issue - sorry. Please instead of webrev.01, review http://cr.openjdk.java.net/~ceisserer/fix12/webrev.02/
In the previous version, I assumed not using a mask means a quadrant-rotated transform, which is not correct as the mask can also be ommited in any case when nearest neighbour interpolation is used. Thanks, Clemens