Fix backspace in the virtual terminal when line is wrapped:

1) Enable backspace to work when wrapped to next line.

2) Correct backspace behavior when most recently typed
   character is in the rightmost column (i.e. in need_wrap state).

Signed-off-by: Joe Peterson <joe@skyrush.com>
---

--- linux-2.6.27-rc6-git5/drivers/char/vt.c.orig	2008-09-20 09:04:55.000000000 -0600
+++ linux-2.6.27-rc6-git5/drivers/char/vt.c	2008-09-20 09:49:22.000000000 -0600
@@ -1130,12 +1130,36 @@ static inline void cr(struct vc_data *vc
 
 static inline void bs(struct vc_data *vc)
 {
-	if (vc->vc_x) {
-		vc->vc_pos -= 2;
-		vc->vc_x--;
+	if (vc->vc_need_wrap) {
+		/*
+		 * If in need_wrap state, do not move cursor,
+		 * but unset need_wrap.
+		 */
 		vc->vc_need_wrap = 0;
-		notify_write(vc, '\b');
+	} else {
+		if (vc->vc_x == 0) {
+			/*
+			 * If at leftmost column, move cursor to end
+			 * of previous line (only if autowrap is on).
+			 */
+			if (vc->vc_decawm) {
+				vc->vc_x = vc->vc_cols - 1;
+				if (vc->vc_y == vc->vc_top) {
+					scrdown(vc,
+						vc->vc_top, vc->vc_bottom, 1);
+					vc->vc_pos += vc->vc_size_row - 2;
+				} else if (vc->vc_y > 0) {
+					vc->vc_y--;
+					vc->vc_pos -= 2;
+				}
+			}
+		} else {
+			/* Normal case: just move cursor back */
+			vc->vc_x--;
+			vc->vc_pos -= 2;
+		}
 	}
+	notify_write(vc, '\b');
 }
 
 static inline void del(struct vc_data *vc)