QTextEdit cursor behavior in Qt 4 is not like Mac OS X (Regression against Qt 3)

There is a difference in the way QTextEdits behave on the Mac when compared to the native applications (for example TextEdit.app)

If the cursor is in the top line of a text field, hitting the up arrow
should move the cursor to the beginning of the document. If the cursor
is in the last line of the document, hitting the down arrow should put
the cursor at the end of the document. QLineEdit seems to exhibit this behavior correctly.

Qt 3 QTextEdits display this desired behavior.