Re: Directory "foo:bar@1:23" destroys Emacs session on M-x tramp-unload-tramp

[Michael Albinus]

Michael Albinus <address@hidden> writes:

Hi,

>> Reproducing this issue is very simple:
>>
>> 1. Run `emacs -Q foo:bar@1:23/asdf` (the directory name is the relevant part)
>>
>> 2. M-x tramp-unload-tramp
>>
>> Effects:
>>
>> a) Error in minibuffer: ‘tramp-file-name-structure’ didn’t match!
>>
>> b) Basic actions like entering text or C-x C-s do not work anymore and 
>> produce
>>    the error message:
>>    Recursive load: "/usr/share/emacs/26.1/lisp/net/tramp.elc",
>>    "/usr/share/emacs/26.1/lisp/net/tramp.elc", [...]
>>
>> c) C-x C-c doesn't fully terminate Emacs. The Emacs process cannot
>> be terminated
>>    by SIGTERM either, only by SIGKILL.
>>
>> I'm not a tramp user but this issue still affects me: When I run Ivy's
>> insert-file after step 1 (see above) I'm having the same problems as 
>> described
>> above.
>>
>> I'm running Emacs 26.1.
>
> I have no Emacs 26.1 at hand, but Emacs 26.3. Behaves similar.
>
> With Emacs 27.0.50, the development version, the error message is
> another one, but Emacs ist still unusable. Will try to understand what's up.

Finally, I could fix it. The problem was, that calling
`tramp-unload-tramp' does load Tramp first if not loaded yet, and
unloads it immediately afterwards. This is not expected to work ...

The fix changes an autoload object of Tramp, you will see this with a
recent checkout of Emacs 27.0.50. Therefore, I'm not confident whether
it works when installing Tramp via GNU ELPA for older Emacsen. Tramp
2.4.3 is scheduled for end of this year, let's see.

Best regards, Michael.