#27 Fix for input box bug

[Sketch-the-Fox]

% TinyFugue version 5.0 beta 8.
Linux opal 2.6.24-24-server #1 SMP Fri Jul 24 23:27:55 UTC 2009 i686GNU/Linux

The cursor in the input box will not move down if the user presses down just above the end of the last line of input.

To reproduce, make your terminal 78 characters wide and put the following in the input box:
111111111 222222222 333333333 444444444 555555555 666666666 777777777 888888888

This should come out as:
111111111 222222222 333333333 444444444 555555555 666666666 777777777 8888888
88

Put the cursor over the third 1 from the left, and press down. The window will beep/flash and the cursor will not move. We think the bug stems from the use of mod() in kb_down_or_recallf in tf-lib/kbfunc.tf. Hopefully this fix doesn't break anything subtle.

Fix by Cheetah@M*U*S*H

[Sketch-the-Fox]

[Sketch-the-Fox]

Ah. Accursed wrapping! Those 8s should be on the same line as the 7s in the first example.