Running texconfig breaks backspace in Bash/MinTTY

[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.

Ken


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