#-> CPAN::Distribution::try_download
sub try_download {
    my($self,$patch) = @_;
    my $norm = $self->normalize($patch);
    my($local_wanted) =
        File::Spec->catfile(
                            $CPAN::Config->{keep_source_where},
                            "authors",
                            "id",
                            split(/\//,$norm),
                           );
    $self->debug("Doing localize") if $CPAN::DEBUG;
    return CPAN::FTP->localize("authors/id/$norm",
                               $local_wanted);
}

{
    my $stdpatchargs = "";
    #-> CPAN::Distribution::patch
    sub patch {
        my($self) = @_;
        $self->debug("checking patches id[$self->{ID}]") if $CPAN::DEBUG;
        my $patches = $self->prefs->{patches};
        $patches ||= "";
        $self->debug("patches[$patches]") if $CPAN::DEBUG;
        if ($patches) {
            return unless @$patches;
            $self->safe_chdir($self->{build_dir});
            CPAN->debug("patches[$patches]") if $CPAN::DEBUG;
            my $patchbin = $CPAN::Config->{patch};
            unless ($patchbin && length $patchbin) {
                $CPAN::Frontend->mydie("No external patch command configured\n\n".
                                       "Please run 'o conf init /patch/'\n\n");
            }
            unless (MM->maybe_command($patchbin)) {
                $CPAN::Frontend->mydie("No external patch command available\n\n".
                                       "Please run 'o conf init /patch/'\n\n");
            }
            $patchbin = CPAN::HandleConfig->safe_quote($patchbin);
            local $ENV{PATCH_GET} = 0; # formerly known as -g0
            unless ($stdpatchargs) {
                my $system = "$patchbin --version |";
                local *FH;
                open FH, $system or die "Could not fork '$system': $!";
                local $/ = "\n";
                my $pversion;
              PARSEVERSION: while (<FH>) {
                    if (/^patch\s+([\d\.]+)/) {
                        $pversion = $1;
                        last PARSEVERSION;
                    }
                }
                if ($pversion) {
                    $stdpatchargs = "-N --fuzz=3";
                } else {
                    $stdpatchargs = "-N";
                }
            }
            my $countedpatches = @$patches == 1 ? "1 patch" : (scalar @$patches . " patches");
            $CPAN::Frontend->myprint("Going to apply $countedpatches:\n");
            for my $patch (@$patches) {
                unless (-f $patch) {
                    if (my $trydl = $self->try_download($patch)) {
                        $patch = $trydl;
                    } else {
                        my $fail = "Could not find patch '$patch'";
                        $CPAN::Frontend->mywarn("$fail; cannot continue\n");
                        $self->{unwrapped} = CPAN::Distrostatus->new("NO -- $fail");
                        delete $self->{build_dir};
                        return;
                    }
                }
                $CPAN::Frontend->myprint("  $patch\n");
                my $readfh = CPAN::Tarzip->TIEHANDLE($patch);

                my $pcommand;
                my $ppp = $self->_patch_p_parameter($readfh);
                if ($ppp eq "applypatch") {
                    $pcommand = "$CPAN::Config->{applypatch} -verbose";
                } else {
                    my $thispatchargs = join " ", $stdpatchargs, $ppp;
                    $pcommand = "$patchbin $thispatchargs";
                }

                $readfh = CPAN::Tarzip->TIEHANDLE($patch); # open again
                my $writefh = FileHandle->new;
                $CPAN::Frontend->myprint("  $pcommand\n");
                unless (open $writefh, "|$pcommand") {
                    my $fail = "Could not fork '$pcommand'";
                    $CPAN::Frontend->mywarn("$fail; cannot continue\n");
                    $self->{unwrapped} = CPAN::Distrostatus->new("NO -- $fail");
                    delete $self->{build_dir};
                    return;
                }
                while (my $x = $readfh->READLINE) {
                    print $writefh $x;
                }
                unless (close $writefh) {
                    my $fail = "Could not apply patch '$patch'";