[Buildroot] [PATCH] support/download/svn: fix date format for archive creation

[Yann E. MORIN <yann.morin.1998@free.fr>]

Vincent, All,

Arnout, question for you toward the end...

On 2021-02-19 15:21 -0600, Vincent Fazio spake thusly:
> Previously we would use the date provided by:
> `svn info --show-item last-changed-date ...`
> 
> The date returned from this command could include sub-second precision
> which is not compatible with the PAX options we specify to GNU tar.
> 
> Now the returned date is massaged to drop the sub-seconds.
> 
> Signed-off-by: Vincent Fazio <vfazio@xes-inc.com>

Thank you for spinning this one right before you sprung on the train to
your holidays!

> ---
>  support/download/svn | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/support/download/svn b/support/download/svn
> index 839dccaf62..ea1032267f 100755
> --- a/support/download/svn
> +++ b/support/download/svn
> @@ -52,6 +52,9 @@ _svn export ${verbose} "${@}" "'${uri}@${rev}'" "'${basename}'"
>  # last line (svn outputs everything on stdout)
>  date="$( _svn info --show-item last-changed-date "'${uri}@${rev}'" |tail -n 1 )"
>  
> +# Drop sub-second precision to play nice with GNU tar's valid_timespec check
> +date="$( date -d "${date}" -uIseconds )"

So, I did some checks about when 'date -d' learnt to deal with
sub-second precision. Not sure when, but it is suported in all the
major distributions still maintained (centos 7, debian jessie, ubuntu
trusty), while it was not in some earlier versions (centos 6, debian
squeeze).

So that's fine for me.

But I wonder whether this should be svn-specific, or whether we should
move it into the generic herlper mk_tar_gz()... Arnout, thoughts?

Regards,
Yann E. MORIN.

>  # Generate the archive.
>  # We did a 'svn export' above, so it's not a working copy (there is no .svn
>  # directory or file to ignore).
> -- 
> 2.30.0
> 

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