--- /dev/null
+package Encode::MIME::Header::ISO_2022_JP;
+
+use strict;
+use base qw(Encode::MIME::Header);
+
+$Encode::Encoding{'MIME-Header-ISO_2022_JP'}
+ = bless {encode => 'B', bpl => 76, Name => 'MIME-Header-ISO_2022_JP'}
+ => __PACKAGE__;
+
+use constant HEAD => '=?ISO-2022-JP?B?';
+use constant TAIL => '?=';
+
+use Encode::CJKConstants qw(%RE);
+
+our $VERSION = do { my @r = (q$Revision: 1.1 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
+
+
+# I owe the below codes totally to
+# Jcode by Dan Kogai & http://www.din.or.jp/~ohzaki/perl.htm#JP_Base64
+
+sub encode {
+ my $self = shift;
+ my $str = shift;
+
+ utf8::encode($str) if( Encode::is_utf8($str) );
+ Encode::from_to($str, 'utf8', 'euc-jp');
+
+ my($trailing_crlf) = ($str =~ /(\n|\r|\x0d\x0a)$/o);
+
+ $str = _mime_unstructured_header($str, $self->{bpl});
+
+ not $trailing_crlf and $str =~ s/(\n|\r|\x0d\x0a)$//o;
+
+ return $str;
+}
+
+
+sub _mime_unstructured_header {
+ my ($oldheader, $bpl) = @_;
+ my $crlf = $oldheader =~ /\n$/;
+ my($header, @words, @wordstmp, $i) = ('');
+
+ $oldheader =~ s/\s+$//;
+
+ @wordstmp = split /\s+/, $oldheader;
+
+ for ($i = 0; $i < $#wordstmp; $i++){
+ if( $wordstmp[$i] !~ /^[\x21-\x7E]+$/ and $wordstmp[$i + 1] !~ /^[\x21-\x7E]+$/){
+ $wordstmp[$i + 1] = "$wordstmp[$i] $wordstmp[$i + 1]";
+ }
+ else{
+ push(@words, $wordstmp[$i]);
+ }
+ }
+
+ push(@words, $wordstmp[-1]);
+
+ for my $word (@words){
+ if ($word =~ /^[\x21-\x7E]+$/) {
+ $header =~ /(?:.*\n)*(.*)/;
+ if (length($1) + length($word) > $bpl) {
+ $header .= "\n $word";
+ }
+ else{
+ $header .= $word;
+ }
+ }
+ else{
+ $header = _add_encoded_word($word, $header, $bpl);
+ }
+
+ $header =~ /(?:.*\n)*(.*)/;
+
+ if(length($1) == $bpl){
+ $header .= "\n ";
+ }
+ else {
+ $header .= ' ';
+ }
+ }
+
+ $header =~ s/\n? $//mg;
+
+ $crlf ? "$header\n" : $header;
+}
+
+
+sub _add_encoded_word {
+ my($str, $line, $bpl) = @_;
+ my $result = '';
+
+ while( length($str) ){
+ my $target = $str;
+ $str = '';
+
+ if(length($line) + 22 + ($target =~ /^(?:$RE{EUC_0212}|$RE{EUC_C})/o) * 8 > $bpl){
+ $line =~ s/[ \t\n\r]*$/\n/;
+ $result .= $line;
+ $line = ' ';
+ }
+
+ while(1){
+ my $iso_2022_jp = $target;
+ Encode::from_to($iso_2022_jp, 'euc-jp', 'iso-2022-jp');
+
+ my $encoded
+ = HEAD . MIME::Base64::encode_base64($iso_2022_jp, '') . TAIL;
+
+ if(length($encoded) + length($line) > $bpl){
+ $target =~ s/($RE{EUC_0212}|$RE{EUC_KANA}|$RE{EUC_C}|$RE{ASCII})$//o;
+ $str = $1 . $str;
+ }
+ else{
+ $line .= $encoded;
+ last;
+ }
+ }
+
+ }
+
+ $result . $line;
+}
+
+
+1;
+__END__
+
--- /dev/null
+
+use Test::More tests => 14;
+
+use strict;
+use Encode;
+
+BEGIN{
+ use_ok('Encode::MIME::Header::ISO_2022_JP');
+}
+
+require_ok('Encode::MIME::Header::ISO_2022_JP');
+
+# below codes are from mime.t in Jcode
+
+my %mime = (
+ "´Á»ú¡¢¥«¥¿¥«¥Ê¡¢¤Ò¤é¤¬¤Ê"
+ => "=?ISO-2022-JP?B?GyRCNEE7eiEiJSslPyUrJUohIiRSJGkkLCRKGyhC?=",
+ "foo bar"
+ => "foo bar",
+ "´Á»ú¡¢¥«¥¿¥«¥Ê¡¢¤Ò¤é¤¬¤Ê¤Îº®¤¸¤Ã¤¿Subject Header."
+ => "=?ISO-2022-JP?B?GyRCNEE7eiEiJSslPyUrJUohIiRSJGkkLCRKJE46LiQ4JEMkPxsoQlN1?=\n =?ISO-2022-JP?B?YmplY3Q=?= Header.",
+);
+
+
+for my $k (keys %mime){
+ $mime{"$k\n"} = $mime{$k} . "\n";
+}
+
+
+for my $decoded (sort keys %mime){
+ my $encoded = $mime{$decoded};
+
+ my $header = Encode::encode('MIME-Header-ISO_2022_JP', decode('euc-jp', $decoded));
+ my $utf8 = Encode::decode('MIME-Header', $header);
+
+ is(encode('euc-jp', $utf8), $decoded);
+ is($header, $encoded);
+}
+
+__END__