Re: Running texconfig breaks backspace in Bash/MinTTY

[Thomas Wolff <towo at towo dot net>]

Am 16.03.2016 um 16:07 schrieb Ken Brown:
> On 3/16/2016 10:00 AM, Adam Dinwoodie wrote:
> > On Wed, Mar 16, 2016 at 08:34:45AM -0400, Ken Brown wrote:
> > > On 3/16/2016 7:45 AM, Adam Dinwoodie wrote:
> > > > Here's an interesting bug: normally in a Bash session in MinTTY,
> > > > backspace and Ctrl+H both delete the previous character, as expected.
> > > > However, after running texconfig and returning to the shell, both the
> > > > backspace key and Ctrl+H appear to just print "^H" to the terminal.
> > > >
> > > > It looks like this is genuinely the terminal trying to render a
> > > > backspace character, rather than just backspacing, given the 
> > > > following:
> > > >
> > > >      $ printf ^H | xxd
> > > >      00000000: 08                                       .
> > > >
> > > > (To get that, I typed "printf {backspace} | xxd".)
> > > >
> > > > It's not clear to me whether this is Bash, MinTTY or texconfig that's
> > > > misbehaving.  Ctrl+W to delete a word, Ctrl+R to get (for me) fzf's
> > > > history search, and using the up and down arrows to navigate 
> > > > history all
> > > > work.  Running Vim, opening a new Bash shell from within the duff one,
> > > > or SSHing to another box has Ctrl+H working just fine within that
> > > > process, but the bugged behaviour resumes when I return to the 
> > > > original
> > > > Bash shell.
> > >
> > > I can't reproduce this on my system.  I tried 'texconfig --help' and
> > > 'texconfig conf'.  What's the precise texconfig command that you
> > > used?
> >
> > I'm just running `texconfig`, with no arguments.  There's a warning
> > prompt, that you press Enter to clear, then there's an interactive menu
> > that appears -- I'm assuming it's something about that interactive menu
> > that's causing the problem.
>
> In the interactive case, texconfig calls texconfig-dialog, which calls 
> dialog.
>
> > Turns out, after some digging, MinTTY's "Keys" > "Backspace sends ^H"
> > setting is critical here -- my .minttyrc has `BackspaceSendsBS=yes`, but
> > if I remove that line and restart MinTTY, everything works fine.  If I
> > add that setting to a fresh Cygwin install that contains only the Base
> > packages, texlive-collection-basic, and their dependencies, I can
> > reproduce the issue.
> >
> > That probably explains why you can't reproduce it, but it still seems
> > like a bug -- I wouldn't expect backspace behaviour to change in that
> > fashion regardless of that bit of configuration.
>
> So it appears to be a MinTTY/dialog issue.
Checking stty -a before and after texconfig reveals that texconfig 
mangles the stty erase setting and does not restore it.
That is clearly a bug of texconfig.
------
Thomas

--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple