bug#39399: tramp depends on unstable details of shell command line processing

[Michael Albinus]

Michael Albinus <michael.albinus@gmx.de> writes:

Hi John,

>> The terminal output from a FreeBSD 13.0 development branch system is
>>
>> _echo
>> #$ _ech ^H
>> #$ _ec ^H
>> #$ _e ^H
>> #$ _ ^H
>> #$  ^Hstty icanon erase ^H cols 32767_echo
>> #$ stty icanon erase ^H cols 32767_ech ^H
>> #$ stty icanon erase ^H cols 32767_ec ^H
>> #$ stty icanon erase ^H cols 32767_e ^H
>> #$ stty icanon erase ^H cols 32767_ ^H
>> #$ stty icanon erase ^H cols 32767 ^H
>> #$
>>
>> with carriage returns between lines.  This does not make sense to
>> emacs, which hangs waiting for something it recognizes.  I can recover
>> by hitting control-G which aborts the tramp connection.
>>
>> This issue is also reported to FreeBSD at
>> https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=243807.
>
> IIUC the discussion in that bug, it is due to the changed libedit of
> FreeBSD 13. Hmm, don't know this beast. But wouldn't it help, if Tramps
> sends initially "stty cooked"?

I've digged further. Likely, the problem can be avoided if we disable
command line editing of the shell. Tramp does it already if the remote
shell is zsh; I've added a similar parameter to the bash invocation. For
other shells, like ksh, I haven't found a simple parameter.

For that class of shells, I've added code which installs a temporary
~/.editrc file, containing the line 'edit off'.

Could you please migrate to Tramp 2.4.3.1 from GNU ELPA? On top of this,
install the appended patch.

And pls report, whether it works for you.

Best regards, Michael.

txtCals2z6XTF.txt
Description: Text Data