[Toybox] GNU tar sparse files

[Rob Landley]

On 4/30/19 10:59 AM, enh via Toybox wrote:
> there's a tar file checked in to AOSP that causes trouble for toybox
> tar. you can find it (and the script that generates it) here:
> 
> https://android.googlesource.com/platform/system/update_engine/+/refs/heads/master/sample_images/

Adding support for sparse files is on my todo list, I just waited for a user to
crop up. Lemme see what I can do...

(Hmmm, we already truncate the file when --overwrite (and O_EXCL otherwise, AHA
bug if O_EXCL fails we don't skippy() when we didn't sendfile(), this is why
proper testing includes ALL THE ERROR PATHS, grrr...)

Ahem. Working on it...

Thanks,

Rob