fmt-merge-msg: avoid open "-|" list form for Perl 5.6

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/git-fmt-merge-msg.perl b/git-fmt-merge-msg.perl
index c34ddc5..a77e94e 100755 (executable)
--- a/git-fmt-merge-msg.perl
+++ b/git-fmt-merge-msg.perl
@@ -28,11 +28,12 @@ sub andjoin {
 }
 
 sub repoconfig {
-       my $fh;
        my $val;
        eval {
-               open $fh, '-|', 'git-repo-config', '--get', 'merge.summary'
-                   or die "$!";
+               my $pid = open(my $fh, '-|');
+               if (!$pid) {
+                       exec('git-repo-config', '--get', 'merge.summary');
+               }
                ($val) = <$fh>;
                close $fh;
        };
@@ -41,25 +42,32 @@ sub repoconfig {
 
 sub current_branch {
        my $fh;
-       open $fh, '-|', 'git-symbolic-ref', 'HEAD' or die "$!";
+       my $pid = open($fh, '-|');
+       die "$!" unless defined $pid;
+       if (!$pid) {
+           exec('git-symbolic-ref', 'HEAD') or die "$!";
+       }
        my ($bra) = <$fh>;
        chomp($bra);
+       close $fh or die "$!";
        $bra =~ s|^refs/heads/||;
        if ($bra ne 'master') {
                $bra = " into $bra";
        } else {
                $bra = "";
        }
-
        return $bra;
 }
 
 sub shortlog {
        my ($tip, $limit) = @_;
        my ($fh, @result);
-       open $fh, '-|', ('git-log', "--max-count=$limit", '--topo-order',
-                        '--pretty=oneline', $tip, '^HEAD')
-           or die "$!";
+       my $pid = open($fh, '-|');
+       die "$!" unless defined $pid;
+       if (!$pid) {
+           exec('git-log', "--max-count=$limit", '--topo-order',
+                '--pretty=oneline', $tip, '^HEAD') or die "$!";
+       }
        while (<$fh>) {
                s/^[0-9a-f]{40}\s+//;
                push @result, $_;