On 2016-05-11 14:06, Yaakov Selkowitz wrote:
> On 2016-05-11 12:09, Andrew Schulman wrote:
>>> Am 10.05.2016 um 20:19 schrieb Andrew Schulman:
>>>> Achim, can you please add /bin/fish and /usr/bin/fish to /etc/shells in
>>>> base-files?
>>>
>>> I seem to remember that this was discussed before.  If you could perhaps
>>> look up that discussion and fill me in what the conclusion was last time
>>> around?
>>
>> Hm, you're right, it was discussed before:
>>
>> https://www.cygwin.com/ml/cygwin/2014-02/msg00696.html
>>
>> I don't know if there was consensus, but the last word there from CGF was
>> that shell packages should run a postinstall step to add themselves to
>> /etc/shells.
>
> While I'm always ready to reconsider previous decisions, this is how it
> appears to be handled in Linux distros.  The implication thereof is that
> (once all packages have been adapted) the default /etc/shells should
> only contain those shells available by default (namely, sh, bash, and
> /sbin/nologin), e.g.:
>
> https://git.fedorahosted.org/cgit/setup.git/tree/shells
>
> (except that /sbin != /usr/sbin on Cygwin.)

AFAICS this should be a two-step process.

1) base-files' default /etc/shells should contain only the shells in a 
Base install, namely:

/bin/sh
/bin/ash
/bin/bash
/bin/dash
/usr/bin/sh
/usr/bin/ash
/usr/bin/bash
/usr/bin/dash
/sbin/nologin

2) Then all non-Base shells, namely:

fish                                         Andrew Schulman
mksh                                         Chris Sutcliffe
posh                                         Jari Aalto
tcsh                                         Corinna Vinschen
zsh                                          Peter A. Castro

will bump release adding an update_etc_shells call, per the attached 
patch, with the path of their shell(s).

>> That seems reasonable. There are questions about the right way to do it,
>> but I'll ask those in a separate thread.
>
> Probably best if we have a cygport function for creating the necessary
> postinstall and preremove commands.

Attached.  Any questions or comments before I make this official?

Or, is this just not worth the trouble?  What are the consequences of 
having shells listed in /etc/shells which aren't on the system?

-- 
Yaakov