[Linuxconsole-dev] Question about early patch bands

[Eric S. R. <es...@sn...>]

In the 2.3.40 patch, I see the following:

--- linux/drivers/char/console.c.orig	Tue Dec 21 00:43:01 1999
+++ linux/drivers/char/console.c	Wed Jan 26 21:21:14 2000
@@ -234,7 +234,7 @@
 	unsigned short *d, *s;
 
 	if (t+nr >= b)
-		nr = b - t - 1;
+		nr = b - t;
 	if (b > video_num_lines || t >= b || nr < 1)
 		return;
 	if (IS_VISIBLE && sw->con_scroll(vc_cons[currcons].d, t, b, SM_UP, nr))
@@ -252,7 +252,7 @@
 	unsigned int step;
 
 	if (t+nr >= b)
-		nr = b - t - 1;
+		nr = b - t;
 	if (b > video_num_lines || t >= b || nr < 1)
 		return;
 	if (IS_VISIBLE && sw->con_scroll(vc_cons[currcons].d, t, b, SM_DOWN, nr))
@@ -365,7 +365,7 @@
 static void update_attr(int currcons)
 {
 	attr = build_attr(currcons, color, intensity, blink, underline, reverse ^ decscnm);
-	video_erase_char = (build_attr(currcons, color, 1, 0, 0, decscnm) << 8) | ' ';
+	video_erase_char = (build_attr(currcons, color, intensity, 0, 0, decscnm) << 8) | ' ';
 }
 
 /* Note: inverting the screen twice should revert to the original state */

It looks like a similar change is in the 2.2.1 patch, but I missed it
amidst the clutter caused by the code reformatting.  The minimized
version I posted does *not* include this change.

So what do these changes do?  What problem are they fixing?
-- 
		<a href="http://www.tuxedo.org/~esr">Eric S. Raymond</a>

The most foolish mistake we could possibly make would be to permit 
the conquered Eastern peoples to have arms.  History teaches that all 
conquerors who have allowed their subject races to carry arms have 
prepared their own downfall by doing so.
        -- Hitler, April 11 1942, revealing the real agenda of "gun control"