bug#34943: 27.0.50; Tramp explicte-shell-file-name not work and not safe local variable

[Shuguang Sun]

Shuguang Sun <shuguang79@qq.com> writes:
> I see that according to the 49.2.6 Per-Connection Local Variables, it use 
> shell-file-name now.

1. shell-file-name to "/bin/bash" defaultly not safey local variables, and it 
pops to (Y/N/!) buffer
```
  (connection-local-set-profile-variables   'remote-bash
   '((shell-file-name . "/bin/bash")
     (shell-command-switch . "-c")))
```
2. In this setting, M-x shell whill ask the path to the shell like:
/plink:username@host.com:/opt/home/username//bin/bash
Even I change to (shell-file-name . "/usr/bin/bash"), it is the same. Bothe 
/bin/bash and /usr/bin/bash exist.



-- 
Best Regards
Shuguang Sun