Rotation arguments in selector and debug screen rotation differ

The rotation arguments ry, rym, rx and rxm do not test for the value displayed in the debug screen (F3).

The selector arguments use a scale from 0 to 360 whereas the debug screen shows the rotation from -180 to 180.

How to reproduce

1. /tp ~ ~ ~ -1 ~
2. /testfor @p[rym=10]
   It finds you although it claims your yaw is -1.

Edit: This seems to take only effect when ry is not specified