patchgit-relink: avoid hard linking in objects/info directory

> git-relink is intended to search for packs and loose objects in
> common between two repositories and to replace the one set with
> hard links to the other. Files other than packs and loose objects
> should not be touched, so add the "info" sub-directory to the
> pattern of directory excludes.
>
> Signed-off-by: Brandon Casey <casey@nrlssc.navy.mil>
> ---
>  git-relink.perl |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/git-relink.perl b/git-relink.perl
> index f6b4f6a..d267404 100755
> --- a/git-relink.perl
> +++ b/git-relink.perl
> @@ -40,7 +40,7 @@ my $master_dir = pop @dirs;
>  opendir(D,$master_dir . "objects/")
>         or die "Failed to open $master_dir/objects/ : $!";
>
> -my @hashdirs = grep !/^\.{1,2}$/, readdir(D);
> +my @hashdirs = grep !/^(\.{1,2}|info)$/, readdir(D);

>>  opendir(D,$master_dir . "objects/")
>>         or die "Failed to open $master_dir/objects/ : $!";
>>
>> -my @hashdirs = grep !/^\.{1,2}$/, readdir(D);
>> +my @hashdirs = grep !/^(\.{1,2}|info)$/, readdir(D);
>
> That looks a bit fragile. If the intent is to get a list of files in
> $master_dir, why not simply say:
>
> my @hashdirs = grep -f, readdir(D);
>
> That will appropriately skip ., .. and any other dirs.

> But I do agree that listing things to skip is a fragile approach
> than listing things you know are safe to relink.
>
> How about doing it this way instead?
>
>  git-relink.perl |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/git-relink.perl b/git-relink.perl
> index f6b4f6a..9101926 100755
> --- a/git-relink.perl
> +++ b/git-relink.perl
> @@ -40,7 +40,7 @@ my $master_dir = pop @dirs;
>  opendir(D,$master_dir . "objects/")
>         or die "Failed to open $master_dir/objects/ : $!";
>
> -my @hashdirs = grep !/^\.{1,2}$/, readdir(D);
> +my @hashdirs = grep { ($_ eq 'pack') || /^[0-9a-f]{2}$/ } readdir(D);

> On 30/01/2008, Junio C Hamano <gitster@pobox.com> wrote:
>> The statement is trying to find directories whose names match
>> /^[0-9a-f]{2}$/ (two hexdigits) or /^pack$/.
> 
> Ah, I see better now.
> 
>> But I do agree that listing things to skip is a fragile approach
>> than listing things you know are safe to relink.
>>
>> How about doing it this way instead?
>>
>>  git-relink.perl |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/git-relink.perl b/git-relink.perl
>> index f6b4f6a..9101926 100755
>> --- a/git-relink.perl
>> +++ b/git-relink.perl
>> @@ -40,7 +40,7 @@ my $master_dir = pop @dirs;
>>  opendir(D,$master_dir . "objects/")
>>         or die "Failed to open $master_dir/objects/ : $!";
>>
>> -my @hashdirs = grep !/^\.{1,2}$/, readdir(D);
>> +my @hashdirs = grep { ($_ eq 'pack') || /^[0-9a-f]{2}$/ } readdir(D);
> 
> Fine, except that one can factorize one step further:
>     grep /^(pack|[0-9a-f]{2})$/, readdir(D);