Re: tramp (2.2.13.25.2); setting GZIP environment variable breaks tramp

[Francesco Potortì]

>> $ echo | gzip -c >/dev/null 2>/dev/null
>>
>> $ echo | env --unset=GZIP gzip -c >/dev/null
>>
>> So one of these would be a simple solution.  But I wonder: since tramp
>> checks for a working compression program, why doesn't it realise right
>> from the start that gzip does not work?  I think it should.
>
>Tramp checks only the remote gzip command, and it uses >/dev/null
>redirection there. Your problem seems to be the local gzip call.

Yes, it's the local one.  Anyway >/dev/null changes nothing, the warning
is on stderr

>Whant happens, if you add "GZIP" to process-environment (without the
>"=VALUE" part)?

That will do the trick.  It should be changed locally with a let binding.

>Alternatively, you could change the first entry in
>tramp-inline-compress-commands to
>
>  '(("env GZIP= gzip" "env GZIP= gzip -d")

Yes.

>(I don't want to use --unset; I'm not sure that all incarnations of env
>do understand this.)

I see.

>Does either of this work?

I haven't tried either on elisp, because in the meantime I have changed
my environment and removed the GZIP env var.  But from shell experiments
they should work:

$ echo | gzip -c >/dev/null
gzip: warning: GZIP environment variable is deprecated; use an alias or script

$ echo | GZIP= gzip -c >/dev/null

$ echo | env GZIP= gzip -c >/dev/null

If you decide on either and send me a patch I can try that.