bug#19731: 24.4; /dev/null is deleted by tramp-sh.el

[Glenn Morris]

Michael Albinus wrote:

>> It seems like a plain bug for bash to do what it does
>
> Looks to me like this.

I don't think the bash folks disagree, but as always the question is
what to do about it:

http://lists.gnu.org/archive/html/bug-bash/2015-01/msg00138.html

>> I wonder: what could Tramp do instead of setting HISTFILE to /dev/null?
>> Could unsetting it result in the same behavior (i.e. not save Tramp's
>> commands to any file)?
>
> That's how I understood the doc. Hope somebody will test it.

http://pubs.opengroup.org/onlinepubs/9699919799/utilities/fc.html

says that

   If the HISTFILE variable is not set, the shell may attempt to access
   or create a file .sh_history in the directory referred to by the HOME
   environment variable.

and indeed by experiment with bash 4.2.45, that is exactly what happes
with HISTFILE unset and using "bash --posix".

So (probably) you can't win.