T2B1: Wrong behavior when auto-mover hits a wall

[matejcik]

This would mostly be observed in "select number of words" where there is no wrap-around.

Hold down an arrow and let the cursor hit the other edge of the selection (e.g. start at 12 and let it go to 33).
Release the button.
Hold down the other direction button.

Expected: cursor starts moving back
Actual: nothing. When you release the button, it will move one place.

The auto-mover somehow moves "behind the selection" instead of stopping, and the opposite button press causes it to "stop" instead of starting to move.