[PATCH] vt: fix broken display when running aptitude

[Mikulas Patocka]

If you run aptitude on framebuffer console, the display is corrupted. The 
corruption is caused by the commit d8ae7242. The patch adds "offset" to 
"start" when calling scr_memsetw, but it forgets to do the same addition 
on a subsequent call to do_update_region.

Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Fixes: d8ae72427187 ("vt: preserve unicode values corresponding to screen characters")
Cc: stable@xxxxxxxxxxxxxxx	# 4.19

---
 drivers/tty/vt/vt.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-2.6/drivers/tty/vt/vt.c
===================================================================
--- linux-2.6.orig/drivers/tty/vt/vt.c	2018-10-23 16:15:08.000000000 +0200
+++ linux-2.6/drivers/tty/vt/vt.c	2018-10-23 16:29:20.000000000 +0200
@@ -1551,7 +1551,7 @@ static void csi_K(struct vc_data *vc, in
 	scr_memsetw(start + offset, vc->vc_video_erase_char, 2 * count);
 	vc->vc_need_wrap = 0;
 	if (con_should_update(vc))
-		do_update_region(vc, (unsigned long) start, count);
+		do_update_region(vc, (unsigned long)(start + offset), count);
 }
 
 static void csi_X(struct vc_data *vc, int vpar) /* erase the following vpar positions */