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

[Krzysztof Żelechowski]

Dnia czwartek, 19 sierpnia 2021 23:32:44 CEST Paul Eggert pisze:
> On 8/19/21 1:43 PM, Krzysztof Żelechowski wrote:
> > The command { gzip b; } fails because it would compress [a] without
> > renaming it.
> > The command { gzip -k b; } would not compress [a], so there is no reason
> > to
> > fail.
> Of course one can use -f to go ahead and compress anyway.

That would silently replace an existing target, which is bad.