/testforblock positions are one off

To reproduce: type /testforblock -532 56 394 69 12.
The error will say: The block at -531,56,394 had the data value of 4 (expected: 12).

This is probably because for /tp, it centers players, so .5 is added automatically if there is no decimal, and then the .5 is detected in checking and is rounded the wrong way.