default value for --compress-level

[Benjamin R. Haskell]

On Tue, 14 Sep 2010, Tomasz Chmielewski wrote:

> What is the default value for --compress-level=? 6? 9?
>
> The fine manual only mentions:
>
>       --compress-level=NUM
>              Explicitly set the compression level to use (see
>              --compress) instead of letting it default.  If NUM is
>              non-zero, the --compress option is implied.
>
>
> Also, what are allowed values? 1-9? 0-9? Something else?