Subject: Re: misc/484: Deleting a tab from sh or csh prompt leaves leftmost character
To: None <>
From: der Mouse <mouse@Collatz.McRCIM.McGill.EDU>
List: netbsd-bugs
Date: 09/19/1994 12:01:47
> Within sh or csh, when you type a tab, the cursor will tab over, but
> if you try to delete that tab, it will not delete the whole tab.  It
> will only delete back to the original cursor location plus one to the
> right.

> Unfortunately, I don't have a fix as of now, and am kind of stumped
> as to what's causing it.  It works fine from vi, so I don't think it
> is a termcap bug.

Especially since termcap is not involved in any way.

> Let me list the scenarios where I have and haven't seen it:

> 	At console( with pccons) with sh: Problem
> 	  ""                     ""  csh: Problem
> 	At console( with pcvt) with sh: Problem
> 	  ""                   ""  csh: Problem
> 	At xterm with sh/csh: Problem
> 	Within vi from console or X with sh/csh: No problem
> 	Telnet to sun from NetBSD with sh/csh: No problem
> 	Telnet to NetBSD from NetBSD with sh/csh: Problem
> 	Telnet to NetBSD from telnet to sun from NetBSD: No problem

I suspect something in the tty driver.  But it's weird.

On a NetBSD/sparc, with a bwtwo RCONSOLE console, I see no problem on
the console, but if I run window(1) on the console and do it in one of
the windows, I see exactly what you describe.

When I rlogin or telnet from a SunOS machine to the NetBSD SPARC, it
behaves fine.  I suspect that under these circumstances, the tab and
its erasure are being handled by the SunOS tty driver....

So, what aspects of the tty driver (a) could affect this and (b) would
differ between the SPARC console and a window pty?  None come to mind;
tab erasure is handled by the generic tty driver code; see ttyoutput()
and ttyrub() in /sys/kern/tty.c....

					der Mouse