[PATCH cygport] lib/src_prep.cygpart: Fix incorrect options passed to unzstd in unpack()

[Jon Turney]

On 29/07/2023 21:55, yak_ex via Cygwin-apps wrote:
> Hi maintainers,
> 
> This is my first post here.
> The attached tiny patch fixes incorrect options passed to unzstd in unpack()
> in lib/src_prep.cygpart.
> 
> `unpack()` invokes `unzstd` for a *.zst file as
> `unzstd -qo file.zst`
> Then, an error occurs as 'stdin is a console, aborting',
> because the `-o` option is to specify an output file name.
> 
> There are some choices to fix it. This patch aligns with handling .gz
> and .bz2 like
> `unzstd -c file.zst > file`.

Thanks very much.

Do you have an example of a cygport which fails without this fix, so I 
can add a test for this?