patchgit-svn: Don't rely on $_ after making a function call

> Signed-off-by: Adam Roben <aroben@apple.com>
> ---
>  git-svn.perl |   10 +++++-----
>  1 files changed, 5 insertions(+), 5 deletions(-)
> 
> diff --git a/git-svn.perl b/git-svn.perl
> index 077d6b3..90f3bc1 100755
> --- a/git-svn.perl
> +++ b/git-svn.perl
> @@ -771,19 +771,19 @@ sub cmt_metadata {
>  sub working_head_info {
>  	my ($head, $refs) = @_;
>  	my ($fh, $ctx) = command_output_pipe('rev-list', $head);
> -	while (<$fh>) {
> -		chomp;
> -		my ($url, $rev, $uuid) = cmt_metadata($_);
> +	while (my $hash = <$fh>) {
> +		chomp($hash);
> +		my ($url, $rev, $uuid) = cmt_metadata($hash);
>  		if (defined $url && defined $rev) {
>  			if (my $gs = Git::SVN->find_by_url($url)) {
>  				my $c = $gs->rev_db_get($rev);
> -				if ($c && $c eq $_) {
> +				if ($c && $c eq $hash) {
>  					close $fh; # break the pipe
>  					return ($url, $rev, $uuid, $gs);
>  				}
>  			}
>  		}
> -		unshift @$refs, $_ if $refs;
> +		unshift @$refs, $hash if $refs;
>  	}
>  	command_close_pipe($fh, $ctx);
>  	(undef, undef, undef, undef);
> -- 
> 1.5.2.rc0.14.g520d-dirty
> 

> Adam Roben <aroben@apple.com> wrote:
>> Many functions and operators in perl set $_, so its value cannot  
>> be relied upon
>> after calling arbitrary functions. The solution is simply to copy  
>> the value of
>> $_ into a local variable that will not get overwritten.
>
> Does this fix any particular bug?  It looks right to me
> and makes the code easier to follow, so;

> Adam Roben <aroben@apple.com> wrote:
>> Many functions and operators in perl set $_, so its value cannot be relied upon
>> after calling arbitrary functions. The solution is simply to copy the value of
>> $_ into a local variable that will not get overwritten.
>
> Does this fix any particular bug?  It looks right to me
> and makes the code easier to follow, so;