>Number:         4843
>Category:       port-i386
>Synopsis:       pcvt cursor jumps into false line after crossing-reentering the line
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    gnats-admin (GNATS administrator)
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Jan 19 13:35:00 1998
>Last-Modified:
>Originator:     Thorsten Frueauf
>Organization:
private
	
>Release:        <NetBSD-current source date> NetBSD 1.3B from 18.1.1998
>Environment:
	
System: NetBSD cyberlap 1.3B NetBSD 1.3B (CYBERLAP) #1: Sun Jan 18 23:16:34 MET 1998 frueauf@di-frueauf:/usr/src/sys/arch/i386/compile/CYBERLAP i386


>Description:
	
Note that I choosed the category port-i386 - cause I noted it there -
but it is possible that other ports that use pcvt have the same problem:

If one types chars at the shell prompt so that the line lenght exceeds
(in my case 90 chars), navigates back with the cursor into the line and then
deletes chars until the typed chars would fit into the beginning line -
the cursor jumps one line too high!

>How-To-Repeat:
	

Compile a kernel with pcvt support:

vt0     at isa? port 0x60 irq 1
options         PCVT_CTRL_ALT_DEL
options         PCVT_NSCREENS=8
options         COLOR_KERNEL_BG=BG_BLACK
options         GERMAN_KBD

TERM=pc3

Login, type enough chars so that you need another line, then navigate back
with cursor keys to the first line and start deleting chars until the last
ones move back into this first line - just when you expect the last char to
jump into the beginning line, the cursor jumps one line higher instead -
and you will need ^L to view the right console contents.

>Fix:
	
I really tryed to understand i386/isa/pcvt/* - but I failed, and had not
too much time to spend, so I just report it without a fix, sorry :-(
>Audit-Trail:
>Unformatted:
pcvt cursor jumps into false line after crossing-reentering the line