Re: stty erase WTF

[Thor Lancelot Simon <tls%panix.com@localhost>]

On Tue, Jan 19, 2016 at 10:41:15AM +0000, Michael van Elst wrote:
> tls%panix.com@localhost (Thor Lancelot Simon) writes:
> 
> >1) On my ssh client, stty shows erase is ^?
> 
> Which apparently is wrong :-)
> 
> >The culprit appears to be these lines in /root/.profile:
> 
> >	if [ -x /usr/bin/tset ]; then
> >        	eval $(tset -sQrm 'unknown:?unknown')
> >	fi
> 
> Here you tell it to configure the tty for $TERM which
> is probably 'xterm' and which asks for erase = ^H.
> Trust your terminfo database.

No, see, I didn't tell it to do anything except make erase ^? (by
explicitly sending that configuration detail over the SSH session).

All the code and config files in question are the default ones that
come with NetBSD, with the result that we can be sure *I* didn't
break my terminal configuration; NetBSD did.

I appreciate the fact that you fixed a longstanding bug in tset,
which exposed this other longstanding bug in the system.  However,
I don't think it's reasonable to claim that the resulting bug,
which impacts large numbers of users, is their fault.  They got
the buggy shell startup files from us, after all.

I am inclined to question whether it is reasonable to trust a
static configuration database like terminfo about these configurable
terminal settings.  I do appreciate that on hardwired terminals they
were often not configurable.  But there are few of those left except
system consoles.  I would suggest that in fact, less users would lose
if we were to patch terminfo to override its static value for erase
with what is available from the tty!

A compromise, any compromise, to disable this exasperating behavior
in the case of ptys does sound like it would work.