Re: [PATCH] system: Add "--" after "-c" for sh (BZ #28519)

[Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>]

On 27/03/23 16:50, Zack Weinberg via Libc-alpha wrote:
> On Mon, Mar 27, 2023, at 3:34 PM, Cristian Rodríguez via Libc-alpha wrote:
>> On Mon, Mar 27, 2023 at 3:56 PM Adhemerval Zanella Netto via Libc-
>> alpha <libc-alpha@sourceware.org> wrote:
>>
>>> I am not sure if it should be ok to break such environments, at least
>>> there are available shells in some environments.
>>
>> Isn't a posix compliant shell already required as "/bin/sh" ? if it is
>> not in writing..it is already de facto required.
> 
> I wouldn't go so far as to say that, _but_ setting a version of the C
> shell as /bin/sh is definitely an improper system configuration and will
> break tons of other things.
> 
>> A lot of work has already been done to get basic components running
>> with dash which has strict compliance as goals.
> 
> You're thinking about this patch from the wrong end of things; whether
> this is a safe change to make is not about other programs that might not
> work with _no more than_ the features specified by POSIX for /bin/sh.
> Rather, it is a question of whether glibc can safely assume availability
> of _all of_ the features specified by POSIX for /bin/sh, in particular
> unusual corners of command line option handling.
> 
> I think it would be a good idea to test this patch on a system where
> /bin/sh is busybox sh, and one where /bin/sh is mksh.
> 
> zw


Indeed and and I am leaning to make glibc assume that _PATH_BSHELL should
support at least some minimum POSIX features, which includes '--' as mark 
the end of the options.