nce;
    unless ( $inst->{request} ) {
        require MT::Request;
        $inst->{request} = MT::Request->instance;
    }
    if (@_) {
        $inst->{request}->stash(@_);
    }
    else {
        $inst->{request};
    }
}

sub log {
    my $mt = shift;
    unless ($plugins_installed) {
        # finish init_schema here since we have to log something
        # to the database.
        $mt->init_schema();
    }
    my $msg;
    if ( !@_ ) {    # single parameter to log, so $mt must be message
        $msg = $mt;
        $mt  = MT->instance;
    }
    else {          # multiple parameters to log; second one is message
        $msg = shift;
    }
    my $log_class = $mt->model('log');
    my $log = $log_class->new();
    if ( ref $msg eq 'HASH' ) {
        $log->set_values($msg);
    }
    elsif ( ( ref $msg ) && ( UNIVERSAL::isa( $msg, 'MT::Log' ) ) ) {
        $log = $msg;
    }
    else {
        $log->message($msg);
    }
    $log->level( MT::Log::INFO() )
      unless defined $log->level;
    $log->class('system')
      unless defined $log->class;
    $log->save();
    print STDERR MT->translate( "Message: [_1]", $log->message ) . "\n"
      if $MT::DebugMode;
}
my $plugin_full_path;

sub run_tasks {
    my $mt = shift;
    require MT::TaskMgr;
    MT::TaskMgr->run_tasks(@_);
}

sub add_plugin {
    my $class = shift;
    my ($plugin) = @_;
    if ( ref $plugin eq 'HASH' ) {
        require MT::Plugin;
        $plugin = new MT::Plugin($plugin);
    }
    $plugin->{name} ||= $plugin_sig;
    $plugin->{plugin_sig} = $plugin_sig;

    my $id = $plugin->id;
    unless ($plugin_envelope) {
        warn "MT->add_plugin improperly called outside of MT plugin load loop.";
        return;
    }
    $plugin->envelope($plugin_envelope);
    Carp::confess("You cannot register multiple plugin objects from a single script. $plugin_sig")
      if exists( $Plugins{$plugin_sig} )
      && ( exists $Plugins{$plugin_sig}{object} );

    $Components{ lc $id } = $plugin if $id;
    $Plugins{$plugin_sig}{object} = $plugin;
    $plugin->{full_path}  = $plugin_full_path;
    $plugin->path($plugin_full_path);
    unless ( $plugin->{registry} && ( %{ $plugin->{registry} } ) ) {
        $plugin->{registry} = $plugin_registry;
    }
    if ( $plugin->{registry} ) {
        if ( my $settings = $plugin->{registry}{config_settings} ) {
            $settings = $plugin->{registry}{config_settings} = $settings->()
              if ref($settings) eq 'CODE';
            $class->config->define($settings);
        }
    }
    push @Components, $plugin;
    1;
}

our %CallbackAlias;
our $CallbacksEnabled = 1;
my %CallbacksEnabled;
my @Callbacks;

sub add_callback {
    my $class = shift;
    my ( $meth, $priority, $plugin, $code ) = @_;
    if ( $meth =~ m/^(.+::)?([^\.]+)(\..+)?$/ ) {

        # Remap (whatever)::(name).(something)
        if ( exists $CallbackAlias{$2} ) {
            $meth = $CallbackAlias{$2};
            $meth = $1 . $meth if $1;
            $meth = $meth . $3 if $3;
        }
    }
    $meth = $CallbackAlias{$meth} if exists $CallbackAlias{$meth};
    my $internal = 0;
    if ( ref $plugin ) {
        if ( ( defined $mt_inst ) && ( $plugin == $mt_inst ) ) {
            $plugin   = undef;
            $internal = 1;
        }
        elsif ( !UNIVERSAL::isa( $plugin, "MT::Component" ) ) {
            return $class->trans_error(
"If present, 3rd argument to add_callback must be an object of type MT::Component or MT::Plugin"
            );
        }
    }
    if ( ( ref $code ) ne 'CODE' ) {
        if ( ref $code ) {
            return $class->trans_error(
                '4th argument to add_callback must be a CODE reference.');
        }
        else {
            # Defer until call