bug#50097: gzip: add "--keep" option to keep original files unchanged

[Antonio Diaz Diaz]

Rodrigo Campos wrote:
> > { >>a && ln a b && gzip -k b
> > }
>
> Exactly, the original file is unaffected, therefore nothing to fix in
> this specific patch. Note the same happens without "-k" too.

I think the point of Krzysztof is that the patch is incomplete because, in 
addition to keep the original file, it should also allow the (de)compression 
of links without forcing the user to type also '-f' for no apparent reason.

$ touch a && ln a b && ls -go *
-rw-r--r-- 2 0 Aug 19 15:29 a
-rw-r--r-- 2 0 Aug 19 15:29 b
$ gzip -k b
gzip: b has 1 other link  -- unchanged
$ lzip -k b
$ ls -go *
-rw-r--r-- 2  0 Aug 19 15:29 a
-rw-r--r-- 2  0 Aug 19 15:29 b
-rw-r--r-- 1 36 Aug 19 15:29 b.lz
$ gzip -k -f b
$ ls -go *
-rw-r--r-- 2  0 Aug 19 15:29 a
-rw-r--r-- 2  0 Aug 19 15:29 b
-rw-r--r-- 1 22 Aug 19 15:29 b.gz
-rw-r--r-- 1 36 Aug 19 15:29 b.lz


Best regards,
Antonio.