Problem with Git.pm bidi_pipe methods

Hi,

To be able to call commit-tree from a Perl program, I had to use command_bidi_pipe() to pass the message on standard input, and get the new commit id on standard output. The only problem I have is that the method doesn't work (or at least, doesn't work like the other command_... methods).

    sub command_bidi_pipe {
        my ($pid, $in, $out);
        $pid = open2($in, $out, 'git', @_);
        return ($pid, $in, $out, join(' ', @_));
    }

First, it calls git in the current working dir, when all the other command_... methods do the appropriate chdir depending on the Git object.

Second, it can't be used as a method, since $self is not removed from @_ before calling open2, leading to errors such as this one:

    git: 'Git=HASH(0x82f898c)' is not a git-command. See 'git --help'.

Third, no access is given to STDERR (open3 may help).

I'm very sorry to complain without proposing a patch.

I think solving the current directory problem is probably going to be difficult with open2/open3, since open2 does the fork+exec, whereas Git.pm handles the fork+chdir+exec itself for the other command_... methods. And so there is no room to chdir when calling open2.