Fix a typo

1 files changed, 460 insertions, 239 deletions

diff --git a/gnu/usr.bin/perl/ext/Encode/Encode.pm b/gnu/usr.bin/perl/ext/Encode/Encode.pm
index 635de301a2d..af5527ed3fc 100644
--- a/gnu/usr.bin/perl/ext/Encode/Encode.pm
+++ b/gnu/usr.bin/perl/ext/Encode/Encode.pm
@@ -1,12 +1,13 @@
 #
-# $Id: Encode.pm,v 1.75 2002/06/01 18:07:42 dankogai Exp $
+# $Id: Encode.pm,v 2.35 2009/07/13 00:49:38 dankogai Exp $
 #
 package Encode;
 use strict;
-our $VERSION = do { my @r = (q$Revision: 1.75 $ =~ /\d+/g); sprintf "%d."."%02d" x $#r, @r };
-our $DEBUG = 0;
+use warnings;
+our $VERSION = sprintf "%d.%02d", q$Revision: 2.35 $ =~ /(\d+)/g;
+sub DEBUG () { 0 }
 use XSLoader ();
-XSLoader::load(__PACKAGE__, $VERSION);
+XSLoader::load( __PACKAGE__, $VERSION );
 
 require Exporter;
 use base qw/Exporter/;
@@ -14,34 +15,35 @@ use base qw/Exporter/;
 # Public, encouraged API is exported by default
 
 our @EXPORT = qw(
-  decode  decode_utf8  encode  encode_utf8
-  encodings  find_encoding
+  decode  decode_utf8  encode  encode_utf8 str2bytes bytes2str
+  encodings  find_encoding clone_encoding
 );
-
-our @FB_FLAGS  = qw(DIE_ON_ERR WARN_ON_ERR RETURN_ON_ERR LEAVE_SRC
-		    PERLQQ HTMLCREF XMLCREF);
-our @FB_CONSTS = qw(FB_DEFAULT FB_CROAK FB_QUIET FB_WARN
-		    FB_PERLQQ FB_HTMLCREF FB_XMLCREF);
-
-our @EXPORT_OK =
-    (
-     qw(
-       _utf8_off _utf8_on define_encoding from_to is_16bit is_8bit
-       is_utf8 perlio_ok resolve_alias utf8_downgrade utf8_upgrade
+our @FB_FLAGS = qw(
+  DIE_ON_ERR WARN_ON_ERR RETURN_ON_ERR LEAVE_SRC
+  PERLQQ HTMLCREF XMLCREF STOP_AT_PARTIAL
+);
+our @FB_CONSTS = qw(
+  FB_DEFAULT FB_CROAK FB_QUIET FB_WARN
+  FB_PERLQQ FB_HTMLCREF FB_XMLCREF
+);
+our @EXPORT_OK = (
+    qw(
+      _utf8_off _utf8_on define_encoding from_to is_16bit is_8bit
+      is_utf8 perlio_ok resolve_alias utf8_downgrade utf8_upgrade
       ),
-     @FB_FLAGS, @FB_CONSTS,
-    );
+    @FB_FLAGS, @FB_CONSTS,
+);
 
-our %EXPORT_TAGS =
-    (
-     all          =>  [ @EXPORT, @EXPORT_OK ],
-     fallbacks    =>  [ @FB_CONSTS ],
-     fallback_all =>  [ @FB_CONSTS, @FB_FLAGS ],
-    );
+our %EXPORT_TAGS = (
+    all          => [ @EXPORT,    @EXPORT_OK ],
+    default      => [ @EXPORT ],
+    fallbacks    => [ @FB_CONSTS ],
+    fallback_all => [ @FB_CONSTS, @FB_FLAGS ],
+);
 
 # Documentation moved after __END__ for speed - NI-S
 
-our $ON_EBCDIC = (ord("A") == 193);
+our $ON_EBCDIC = ( ord("A") == 193 );
 
 use Encode::Alias;
 
@@ -49,53 +51,57 @@ use Encode::Alias;
 our %Encoding;
 our %ExtModule;
 require Encode::Config;
-eval { require Encode::ConfigLocal };
-
-sub encodings
-{
+#  See
+#  https://bugzilla.redhat.com/show_bug.cgi?id=435505#c2
+#  to find why sig handers inside eval{} are disabled.
+eval {
+    local $SIG{__DIE__};
+    local $SIG{__WARN__};
+    require Encode::ConfigLocal;
+};
+
+sub encodings {
     my $class = shift;
     my %enc;
-    if (@_ and $_[0] eq ":all"){
-	%enc = ( %Encoding, %ExtModule );
-    }else{
-	%enc = %Encoding;
-	for my $mod (map {m/::/o ? $_ : "Encode::$_" } @_){
-	    $DEBUG and warn $mod;
-	    for my $enc (keys %ExtModule){
-		$ExtModule{$enc} eq $mod and $enc{$enc} = $mod;
-	    }
-	}
+    if ( @_ and $_[0] eq ":all" ) {
+        %enc = ( %Encoding, %ExtModule );
     }
-    return
-	sort { lc $a cmp lc $b }
-             grep {!/^(?:Internal|Unicode|Guess)$/o} keys %enc;
+    else {
+        %enc = %Encoding;
+        for my $mod ( map { m/::/o ? $_ : "Encode::$_" } @_ ) {
+            DEBUG and warn $mod;
+            for my $enc ( keys %ExtModule ) {
+                $ExtModule{$enc} eq $mod and $enc{$enc} = $mod;
+            }
+        }
+    }
+    return sort { lc $a cmp lc $b }
+      grep      { !/^(?:Internal|Unicode|Guess)$/o } keys %enc;
 }
 
-sub perlio_ok{
-    my $obj = ref($_[0]) ? $_[0] : find_encoding($_[0]);
+sub perlio_ok {
+    my $obj = ref( $_[0] ) ? $_[0] : find_encoding( $_[0] );
     $obj->can("perlio_ok") and return $obj->perlio_ok();
-    return 0; # safety net
+    return 0;    # safety net
 }
 
-sub define_encoding
-{
+sub define_encoding {
     my $obj  = shift;
     my $name = shift;
     $Encoding{$name} = $obj;
     my $lc = lc($name);
-    define_alias($lc => $obj) unless $lc eq $name;
-    while (@_){
-	my $alias = shift;
-	define_alias($alias, $obj);
+    define_alias( $lc => $obj ) unless $lc eq $name;
+    while (@_) {
+        my $alias = shift;
+        define_alias( $alias, $obj );
     }
     return $obj;
 }
 
-sub getEncoding
-{
-    my ($class, $name, $skip_external) = @_;
+sub getEncoding {
+    my ( $class, $name, $skip_external ) = @_;
 
-    ref($name) && $name->can('new_sequence') and return $name;
+    ref($name) && $name->can('renew') and return $name;
     exists $Encoding{$name} and return $Encoding{$name};
     my $lc = lc $name;
     exists $Encoding{$lc} and return $Encoding{$lc};
@@ -105,161 +111,217 @@ sub getEncoding
     $lc ne $name and $oc = $class->find_alias($lc);
     defined($oc) and return $oc;
 
-    unless ($skip_external)
-    {
-	if (my $mod = $ExtModule{$name} || $ExtModule{$lc}){
-	    $mod =~ s,::,/,g ; $mod .= '.pm';
-	    eval{ require $mod; };
-	    exists $Encoding{$name} and return $Encoding{$name};
-	}
+    unless ($skip_external) {
+        if ( my $mod = $ExtModule{$name} || $ExtModule{$lc} ) {
+            $mod =~ s,::,/,g;
+            $mod .= '.pm';
+            eval { require $mod; };
+            exists $Encoding{$name} and return $Encoding{$name};
+        }
     }
     return;
 }
 
-sub find_encoding
-{
-    my ($name, $skip_external) = @_;
-    return __PACKAGE__->getEncoding($name,$skip_external);
+sub find_encoding($;$) {
+    my ( $name, $skip_external ) = @_;
+    return __PACKAGE__->getEncoding( $name, $skip_external );
 }
 
-sub resolve_alias {
+sub resolve_alias($) {
     my $obj = find_encoding(shift);
     defined $obj and return $obj->name;
     return;
 }
 
-sub encode($$;$)
-{
-    my ($name, $string, $check) = @_;
-    $check ||=0;
+sub clone_encoding($) {
+    my $obj = find_encoding(shift);
+    ref $obj or return;
+    eval { require Storable };
+    $@ and return;
+    return Storable::dclone($obj);
+}
+
+sub encode($$;$) {
+    my ( $name, $string, $check ) = @_;
+    return undef unless defined $string;
+    $string .= '' if ref $string;    # stringify;
+    $check ||= 0;
+    unless ( defined $name ) {
+        require Carp;
+        Carp::croak("Encoding name should not be undef");
+    }
     my $enc = find_encoding($name);
-    unless(defined $enc){
-	require Carp;
-	Carp::croak("Unknown encoding '$name'");
+    unless ( defined $enc ) {
+        require Carp;
+        Carp::croak("Unknown encoding '$name'");
     }
-    my $octets = $enc->encode($string,$check);
-    return undef if ($check && length($string));
+    my $octets = $enc->encode( $string, $check );
+    $_[1] = $string if $check and !ref $check and !( $check & LEAVE_SRC() );
     return $octets;
 }
+*str2bytes = \&encode;
 
-sub decode($$;$)
-{
-    my ($name,$octets,$check) = @_;
-    $check ||=0;
+sub decode($$;$) {
+    my ( $name, $octets, $check ) = @_;
+    return undef unless defined $octets;
+    $octets .= '' if ref $octets;
+    $check ||= 0;
     my $enc = find_encoding($name);
-    unless(defined $enc){
-	require Carp;
-	Carp::croak("Unknown encoding '$name'");
+    unless ( defined $enc ) {
+        require Carp;
+        Carp::croak("Unknown encoding '$name'");
     }
-    my $string = $enc->decode($octets,$check);
-    $_[1] = $octets if $check;
+    my $string = $enc->decode( $octets, $check );
+    $_[1] = $octets if $check and !ref $check and !( $check & LEAVE_SRC() );
     return $string;
 }
+*bytes2str = \&decode;
 
-sub from_to($$$;$)
-{
-    my ($string,$from,$to,$check) = @_;
-    $check ||=0;
+sub from_to($$$;$) {
+    my ( $string, $from, $to, $check ) = @_;
+    return undef unless defined $string;
+    $check ||= 0;
     my $f = find_encoding($from);
-    unless (defined $f){
-	require Carp;
-	Carp::croak("Unknown encoding '$from'");
+    unless ( defined $f ) {
+        require Carp;
+        Carp::croak("Unknown encoding '$from'");
     }
     my $t = find_encoding($to);
-    unless (defined $t){
-	require Carp;
-	Carp::croak("Unknown encoding '$to'");
+    unless ( defined $t ) {
+        require Carp;
+        Carp::croak("Unknown encoding '$to'");
     }
-    my $uni = $f->decode($string,$check);
-    return undef if ($check && length($string));
-    $string =  $t->encode($uni,$check);
-    return undef if ($check && length($uni));
-    return defined($_[0] = $string) ? length($string) : undef ;
+    my $uni = $f->decode($string);
+    $_[0] = $string = $t->encode( $uni, $check );
+    return undef if ( $check && length($uni) );
+    return defined( $_[0] ) ? length($string) : undef;
 }
 
-sub encode_utf8($)
-{
+sub encode_utf8($) {
     my ($str) = @_;
     utf8::encode($str);
     return $str;
 }
 
-sub decode_utf8($)
-{
-    my ($str) = @_;
-    return undef unless utf8::decode($str);
-    return $str;
+sub decode_utf8($;$) {
+    my ( $str, $check ) = @_;
+    return $str if is_utf8($str);
+    if ($check) {
+        return decode( "utf8", $str, $check );
+    }
+    else {
+        return decode( "utf8", $str );
+        return $str;
+    }
 }
 
-predefine_encodings();
+predefine_encodings(1);
 
 #
 # This is to restore %Encoding if really needed;
 #
 
-sub predefine_encodings{
-    use Encode::Encoding;
+sub predefine_encodings {
+    require Encode::Encoding;
+    no warnings 'redefine';
+    my $use_xs = shift;
     if ($ON_EBCDIC) {
-	# was in Encode::UTF_EBCDIC
-	package Encode::UTF_EBCDIC;
-	push @Encode::UTF_EBCDIC::ISA, 'Encode::Encoding';
-	*decode = sub{
-	    my ($obj,$str,$chk) = @_;
-	    my $res = '';
-	    for (my $i = 0; $i < length($str); $i++) {
-		$res .=
-		    chr(utf8::unicode_to_native(ord(substr($str,$i,1))));
-	    }
-	    $_[1] = '' if $chk;
-	    return $res;
-	};
-	*encode = sub{
-	    my ($obj,$str,$chk) = @_;
-	    my $res = '';
-	    for (my $i = 0; $i < length($str); $i++) {
-		$res .=
-		    chr(utf8::native_to_unicode(ord(substr($str,$i,1))));
-	    }
-	    $_[1] = '' if $chk;
-	    return $res;
-	};
-	$Encode::Encoding{Unicode} =
-	    bless {Name => "UTF_EBCDIC"} => "Encode::UTF_EBCDIC";
-    } else {
-	package Encode::Internal;
-	push @Encode::Internal::ISA, 'Encode::Encoding';
-	*decode = sub{
-	    my ($obj,$str,$chk) = @_;
-	    utf8::upgrade($str);
-	    $_[1] = '' if $chk;
-	    return $str;
-	};
-	*encode = \&decode;
-	$Encode::Encoding{Unicode} =
-	    bless {Name => "Internal"} => "Encode::Internal";
+
+        # was in Encode::UTF_EBCDIC
+        package Encode::UTF_EBCDIC;
+        push @Encode::UTF_EBCDIC::ISA, 'Encode::Encoding';
+        *decode = sub {
+            my ( $obj, $str, $chk ) = @_;
+            my $res = '';
+            for ( my $i = 0 ; $i < length($str) ; $i++ ) {
+                $res .=
+                  chr(
+                    utf8::unicode_to_native( ord( substr( $str, $i, 1 ) ) )
+                  );
+            }
+            $_[1] = '' if $chk;
+            return $res;
+        };
+        *encode = sub {
+            my ( $obj, $str, $chk ) = @_;
+            my $res = '';
+            for ( my $i = 0 ; $i < length($str) ; $i++ ) {
+                $res .=
+                  chr(
+                    utf8::native_to_unicode( ord( substr( $str, $i, 1 ) ) )
+                  );
+            }
+            $_[1] = '' if $chk;
+            return $res;
+        };
+        $Encode::Encoding{Unicode} =
+          bless { Name => "UTF_EBCDIC" } => "Encode::UTF_EBCDIC";
+    }
+    else {
+
+        package Encode::Internal;
+        push @Encode::Internal::ISA, 'Encode::Encoding';
+        *decode = sub {
+            my ( $obj, $str, $chk ) = @_;
+            utf8::upgrade($str);
+            $_[1] = '' if $chk;
+            return $str;
+        };
+        *encode = \&decode;
+        $Encode::Encoding{Unicode} =
+          bless { Name => "Internal" } => "Encode::Internal";
     }
 
     {
-	# was in Encode::utf8
-	package Encode::utf8;
-	push @Encode::utf8::ISA, 'Encode::Encoding';
-	*decode = sub{
-	    my ($obj,$octets,$chk) = @_;
-	    my $str = Encode::decode_utf8($octets);
-	    if (defined $str) {
-		$_[1] = '' if $chk;
-		return $str;
-	    }
-	    return undef;
-	};
-	*encode = sub {
-	    my ($obj,$string,$chk) = @_;
-	    my $octets = Encode::encode_utf8($string);
-	    $_[1] = '' if $chk;
-	    return $octets;
-	};
-	$Encode::Encoding{utf8} =
-	    bless {Name => "utf8"} => "Encode::utf8";
+
+        # was in Encode::utf8
+        package Encode::utf8;
+        push @Encode::utf8::ISA, 'Encode::Encoding';
+
+        #
+        if ($use_xs) {
+            Encode::DEBUG and warn __PACKAGE__, " XS on";
+            *decode = \&decode_xs;
+            *encode = \&encode_xs;
+        }
+        else {
+            Encode::DEBUG and warn __PACKAGE__, " XS off";
+            *decode = sub {
+                my ( $obj, $octets, $chk ) = @_;
+                my $str = Encode::decode_utf8($octets);
+                if ( defined $str ) {
+                    $_[1] = '' if $chk;
+                    return $str;
+                }
+                return undef;
+            };
+            *encode = sub {
+                my ( $obj, $string, $chk ) = @_;
+                my $octets = Encode::encode_utf8($string);
+                $_[1] = '' if $chk;
+                return $octets;
+            };
+        }
+        *cat_decode = sub {    # ($obj, $dst, $src, $pos, $trm, $chk)
+                               # currently ignores $chk
+            my ( $obj, undef, undef, $pos, $trm ) = @_;
+            my ( $rdst, $rsrc, $rpos ) = \@_[ 1, 2, 3 ];
+            use bytes;
+            if ( ( my $npos = index( $$rsrc, $trm, $pos ) ) >= 0 ) {
+                $$rdst .=
+                  substr( $$rsrc, $pos, $npos - $pos + length($trm) );
+                $$rpos = $npos + length($trm);
+                return 1;
+            }
+            $$rdst .= substr( $$rsrc, $pos );
+            $$rpos = length($$rsrc);
+            return '';
+        };
+        $Encode::Encoding{utf8} =
+          bless { Name => "utf8" } => "Encode::utf8";
+        $Encode::Encoding{"utf-8-strict"} =
+          bless { Name => "utf-8-strict", strict_utf8 => 1 } =>
+          "Encode::utf8";
     }
 }
 
@@ -355,15 +417,13 @@ iso-8859-1 (also known as Latin1),
 
   $octets = encode("iso-8859-1", $string);
 
-B<CAVEAT>: When you run C<$octets = encode("utf8", $string)>, then $octets
-B<may not be equal to> $string.  Though they both contain the same data, the utf8 flag
-for $octets is B<always> off.  When you encode anything, utf8 flag of
-the result is always off, even when it contains completely valid utf8
-string. See L</"The UTF-8 flag"> below.
+B<CAVEAT>: When you run C<$octets = encode("utf8", $string)>, then
+$octets B<may not be equal to> $string.  Though they both contain the
+same data, the UTF8 flag for $octets is B<always> off.  When you
+encode anything, UTF8 flag of the result is always off, even when it
+contains completely valid utf8 string. See L</"The UTF8 flag"> below.
 
-encode($valid_encoding, undef) is harmless but warns you for 
-C<Use of uninitialized value in subroutine entry>. 
-encode($valid_encoding, '') is harmless and warnless.
+If the $string is C<undef> then C<undef> is returned.
 
 =item $string = decode(ENCODING, $octets [, CHECK])
 
@@ -379,19 +439,53 @@ For example, to convert ISO-8859-1 data to a string in Perl's internal format:
 
 B<CAVEAT>: When you run C<$string = decode("utf8", $octets)>, then $string
 B<may not be equal to> $octets.  Though they both contain the same data,
-the utf8 flag for $string is on unless $octets entirely consists of
-ASCII data (or EBCDIC on EBCDIC machines).  See L</"The UTF-8 flag">
+the UTF8 flag for $string is on unless $octets entirely consists of
+ASCII data (or EBCDIC on EBCDIC machines).  See L</"The UTF8 flag">
 below.
 
-decode($valid_encoding, undef) is harmless but warns you for 
-C<Use of uninitialized value in subroutine entry>. 
-decode($valid_encoding, '') is harmless and warnless.
+If the $string is C<undef> then C<undef> is returned.
+
+=item [$obj =] find_encoding(ENCODING)
+
+Returns the I<encoding object> corresponding to ENCODING.  Returns
+undef if no matching ENCODING is find.
+
+This object is what actually does the actual (en|de)coding.
+
+  $utf8 = decode($name, $bytes);
+
+is in fact
+
+  $utf8 = do{
+    $obj = find_encoding($name);
+    croak qq(encoding "$name" not found) unless ref $obj;
+    $obj->decode($bytes)
+  };
+
+with more error checking.
+
+Therefore you can save time by reusing this object as follows;
+
+  my $enc = find_encoding("iso-8859-1");
+  while(<>){
+     my $utf8 = $enc->decode($_);
+     # and do someting with $utf8;
+  }
+
+Besides C<< ->decode >> and C<< ->encode >>, other methods are
+available as well.  For instance, C<< -> name >> returns the canonical
+name of the encoding object.
+
+  find_encoding("latin1")->name; # iso-8859-1
+
+See L<Encode::Encoding> for details.
 
 =item [$length =] from_to($octets, FROM_ENC, TO_ENC [, CHECK])
 
 Converts B<in-place> data between two encodings. The data in $octets
 must be encoded as octets and not as characters in Perl's internal
-format. For example, to convert ISO-8859-1 data to Microsoft's CP1250 encoding:
+format. For example, to convert ISO-8859-1 data to Microsoft's CP1250
+encoding:
 
   from_to($octets, "iso-8859-1", "cp1250");
 
@@ -402,8 +496,8 @@ and to convert it back:
 Note that because the conversion happens in place, the data to be
 converted cannot be a string constant; it must be a scalar variable.
 
-from_to() returns the length of the converted string in octets on success, undef
-otherwise.
+from_to() returns the length of the converted string in octets on
+success, I<undef> on error.
 
 B<CAVEAT>: The following operations look the same but are not quite so;
 
@@ -411,11 +505,25 @@ B<CAVEAT>: The following operations look the same but are not quite so;
   $data = decode("iso-8859-1", $data);  #2
 
 Both #1 and #2 make $data consist of a completely valid UTF-8 string
-but only #2 turns utf8 flag on.  #1 is equivalent to
+but only #2 turns UTF8 flag on.  #1 is equivalent to
 
   $data = encode("utf8", decode("iso-8859-1", $data));
 
-See L</"The UTF-8 flag"> below.
+See L</"The UTF8 flag"> below.
+
+Also note that
+
+  from_to($octets, $from, $to, $check);
+
+is equivalent to
+
+  $octets = encode($to, decode($from, $octets), $check);
+
+Yes, it does not respect the $check during decoding.  It is
+deliberately done that way.  If you need minute control, C<decode>
+then C<encode> as follows;
+
+  $octets = encode($to, decode($from, $octets, $check_from), $check_to);
 
 =item $octets = encode_utf8($string);
 
@@ -483,11 +591,27 @@ exported via C<use Encode qw(resolve_alias)>.
 
 See L<Encode::Alias> for details.
 
+=head2 Finding IANA Character Set Registry names
+
+The canonical name of a given encoding does not necessarily agree with
+IANA IANA Character Set Registry, commonly seen as C<< Content-Type:
+text/plain; charset=I<whatever> >>.  For most cases canonical names
+work but sometimes it does not (notably 'utf-8-strict').
+
+Therefore as of Encode version 2.21, a new method C<mime_name()> is added.
+
+  use Encode;
+  my $enc = find_encoding('UTF-8');
+  warn $enc->name;      # utf-8-strict
+  warn $enc->mime_name; # UTF-8
+
+See also:  L<Encode::Encoding>
+
 =head1 Encoding via PerlIO
 
-If your perl supports I<PerlIO> (which is the default), you can use a PerlIO layer to decode
-and encode directly via a filehandle.  The following two examples
-are totally identical in their functionality.
+If your perl supports I<PerlIO> (which is the default), you can use a
+PerlIO layer to decode and encode directly via a filehandle.  The
+following two examples are totally identical in their functionality.
 
   # via PerlIO
   open my $in,  "<:encoding(shiftjis)", $infile  or die;
@@ -513,47 +637,59 @@ method.
   perlio_ok("euc-jp")
 
 Fortunately, all encodings that come with Encode core are PerlIO-savvy
-except for hz and ISO-2022-kr.  For gory details, see L<Encode::Encoding> and L<Encode::PerlIO>.
+except for hz and ISO-2022-kr.  For gory details, see
+L<Encode::Encoding> and L<Encode::PerlIO>.
 
 =head1 Handling Malformed Data
 
+The optional I<CHECK> argument tells Encode what to do when it
+encounters malformed data.  Without CHECK, Encode::FB_DEFAULT ( == 0 )
+is assumed.
+
+As of version 2.12 Encode supports coderef values for CHECK.  See below.
+
 =over 2
 
-The I<CHECK> argument is used as follows.  When you omit it,
-the behaviour is the same as if you had passed a value of 0 for
-I<CHECK>.
+=item B<NOTE:> Not all encoding support this feature
+
+Some encodings ignore I<CHECK> argument.  For example,
+L<Encode::Unicode> ignores I<CHECK> and it always croaks on error.
+
+=back
+
+Now here is the list of I<CHECK> values available
+
+=over 2
 
 =item I<CHECK> = Encode::FB_DEFAULT ( == 0)
 
-If I<CHECK> is 0, (en|de)code will put a I<substitution character>
-in place of a malformed character.  For UCM-based encodings,
-E<lt>subcharE<gt> will be used.  For Unicode, the code point C<0xFFFD> is used.
-If the data is supposed to be UTF-8, an optional lexical warning
+If I<CHECK> is 0, (en|de)code will put a I<substitution character> in
+place of a malformed character.  When you encode, E<lt>subcharE<gt>
+will be used.  When you decode the code point C<0xFFFD> is used.  If
+the data is supposed to be UTF-8, an optional lexical warning
 (category utf8) is given.
 
 =item I<CHECK> = Encode::FB_CROAK ( == 1)
 
 If I<CHECK> is 1, methods will die on error immediately with an error
 message.  Therefore, when I<CHECK> is set to 1,  you should trap the
-fatal error with eval{} unless you really want to let it die on error.
+error with eval{} unless you really want to let it die.
 
 =item I<CHECK> = Encode::FB_QUIET
 
 If I<CHECK> is set to Encode::FB_QUIET, (en|de)code will immediately
-return the portion of the data that has been processed so far when
-an error occurs. The data argument will be overwritten with
-everything after that point (that is, the unprocessed part of data).
-This is handy when you have to call decode repeatedly in the case
-where your source data may contain partial multi-byte character
-sequences, for example because you are reading with a fixed-width
-buffer. Here is some sample code that does exactly this:
-
-  my $data = ''; my $utf8 = '';
-  while(defined(read $fh, $buffer, 256)){
-    # buffer may end in a partial character so we append
-    $data .= $buffer;
-    $utf8 .= decode($encoding, $data, Encode::FB_QUIET);
-    # $data now contains the unprocessed partial character
+return the portion of the data that has been processed so far when an
+error occurs. The data argument will be overwritten with everything
+after that point (that is, the unprocessed part of data).  This is
+handy when you have to call decode repeatedly in the case where your
+source data may contain partial multi-byte character sequences,
+(i.e. you are reading with a fixed-width buffer). Here is a sample
+code that does exactly this:
+
+  my $buffer = ''; my $string = '';
+  while(read $fh, $buffer, 256, length($buffer)){
+    $string .= decode($encoding, $buffer, Encode::FB_QUIET);
+    # $buffer now contains the unprocessed partial character
   }
 
 =item I<CHECK> = Encode::FB_WARN
@@ -577,8 +713,10 @@ where I<HHHH> is the Unicode ID of the character that cannot be found
 in the character repertoire of the encoding.
 
 HTML/XML character reference modes are about the same, in place of
-C<\x{I<HHHH>}>, HTML uses C<&#I<NNNN>>; where I<NNNN> is a decimal digit and
-XML uses C<&#xI<HHHH>>; where I<HHHH> is the hexadecimal digit.
+C<\x{I<HHHH>}>, HTML uses C<&#I<NNN>;> where I<NNN> is a decimal number and
+XML uses C<&#xI<HHHH>;> where I<HHHH> is the hexadecimal number.
+
+In Encode 2.10 or later, C<LEAVE_SRC> is also implied.
 
 =item The bitmask
 
@@ -591,17 +729,33 @@ constants via C<use Encode qw(:fallback_all)>.
  DIE_ON_ERR    0x0001             X
  WARN_ON_ERR   0x0002                               X
  RETURN_ON_ERR 0x0004                      X        X
- LEAVE_SRC     0x0008
+ LEAVE_SRC     0x0008                                        X
  PERLQQ        0x0100                                        X
  HTMLCREF      0x0200
  XMLCREF       0x0400
 
-=head2 Unimplemented fallback schemes
+=back
+
+=over 2
+
+=item Encode::LEAVE_SRC
+
+If the C<Encode::LEAVE_SRC> bit is not set, but I<CHECK> is, then the second
+argument to C<encode()> or C<decode()> may be assigned to by the functions. If
+you're not interested in this, then bitwise-or the bitmask with it.
+
+=back
+
+=head2 coderef for CHECK
+
+As of Encode 2.12 CHECK can also be a code reference which takes the
+ord value of unmapped caharacter as an argument and returns a string
+that represents the fallback character.  For instance,
 
-In the future, you will be able to use a code reference to a callback
-function for the value of I<CHECK> but its API is still undecided.
+  $ascii = encode("ascii", $utf8, sub{ sprintf "<U+%04X>", shift });
 
-The fallback scheme does not work on EBCDIC platforms.
+Acts like FB_PERLQQ but E<lt>U+I<XXXX>E<gt> is used instead of
+\x{I<XXXX>}.
 
 =head1 Defining Encodings
 
@@ -617,13 +771,13 @@ arguments are taken as aliases for I<$object>.
 
 See L<Encode::Encoding> for more details.
 
-=head1 The UTF-8 flag
+=head1 The UTF8 flag
 
-Before the introduction of utf8 support in perl, The C<eq> operator
+Before the introduction of Unicode support in perl, The C<eq> operator
 just compared the strings represented by two scalars. Beginning with
-perl 5.8, C<eq> compares two strings with simultaneous consideration
-of I<the utf8 flag>. To explain why we made it so, I will quote page
-402 of C<Programming Perl, 3rd ed.>
+perl 5.8, C<eq> compares two strings with simultaneous consideration of
+I<the UTF8 flag>. To explain why we made it so, I will quote page 402 of
+C<Programming Perl, 3rd ed.>
 
 =over 2
 
@@ -652,38 +806,38 @@ byte-oriented Perl and a character-oriented Perl.
 Back when C<Programming Perl, 3rd ed.> was written, not even Perl 5.6.0
 was born and many features documented in the book remained
 unimplemented for a long time.  Perl 5.8 corrected this and the introduction
-of the UTF-8 flag is one of them.  You can think of this perl notion as of a
-byte-oriented mode (utf8 flag off) and a character-oriented mode (utf8
+of the UTF8 flag is one of them.  You can think of this perl notion as of a
+byte-oriented mode (UTF8 flag off) and a character-oriented mode (UTF8
 flag on).
 
-Here is how Encode takes care of the utf8 flag.
+Here is how Encode takes care of the UTF8 flag.
 
 =over 2
 
 =item *
 
-When you encode, the resulting utf8 flag is always off.
+When you encode, the resulting UTF8 flag is always off.
 
-=item
+=item *
 
-When you decode, the resulting utf8 flag is on unless you can
+When you decode, the resulting UTF8 flag is on unless you can
 unambiguously represent data.  Here is the definition of
 dis-ambiguity.
 
 After C<$utf8 = decode('foo', $octet);>,
 
-  When $octet is...   The utf8 flag in $utf8 is
+  When $octet is...   The UTF8 flag in $utf8 is
   ---------------------------------------------
   In ASCII only (or EBCDIC only)            OFF
   In ISO-8859-1                              ON
   In any other Encoding                      ON
   ---------------------------------------------
 
-As you see, there is one exception, In ASCII.  That way you can assue
+As you see, there is one exception, In ASCII.  That way you can assume
 Goal #1.  And with Encode Goal #2 is assumed but you still have to be
 careful in such cases mentioned in B<CAVEAT> paragraphs.
 
-This utf8 flag is not visible in perl scripts, exactly for the same
+This UTF8 flag is not visible in perl scripts, exactly for the same
 reason you cannot (or you I<don't have to>) see if a scalar contains a
 string, integer, or floating point number.   But you can still peek
 and poke these if you will.  See the section below.
@@ -699,27 +853,83 @@ implementation.  As such, they are efficient but may change.
 
 =item is_utf8(STRING [, CHECK])
 
-[INTERNAL] Tests whether the UTF-8 flag is turned on in the STRING.
+[INTERNAL] Tests whether the UTF8 flag is turned on in the STRING.
 If CHECK is true, also checks the data in STRING for being well-formed
 UTF-8.  Returns true if successful, false otherwise.
 
+As of perl 5.8.1, L<utf8> also has utf8::is_utf8().
+
 =item _utf8_on(STRING)
 
-[INTERNAL] Turns on the UTF-8 flag in STRING.  The data in STRING is
+[INTERNAL] Turns on the UTF8 flag in STRING.  The data in STRING is
 B<not> checked for being well-formed UTF-8.  Do not use unless you
 B<know> that the STRING is well-formed UTF-8.  Returns the previous
-state of the UTF-8 flag (so please don't treat the return value as
+state of the UTF8 flag (so please don't treat the return value as
 indicating success or failure), or C<undef> if STRING is not a string.
 
+This function does not work on tainted values.
+
 =item _utf8_off(STRING)
 
-[INTERNAL] Turns off the UTF-8 flag in STRING.  Do not use frivolously.
-Returns the previous state of the UTF-8 flag (so please don't treat the
+[INTERNAL] Turns off the UTF8 flag in STRING.  Do not use frivolously.
+Returns the previous state of the UTF8 flag (so please don't treat the
 return value as indicating success or failure), or C<undef> if STRING is
 not a string.
 
+This function does not work on tainted values.
+
 =back
 
+=head1 UTF-8 vs. utf8 vs. UTF8
+
+  ....We now view strings not as sequences of bytes, but as sequences
+  of numbers in the range 0 .. 2**32-1 (or in the case of 64-bit
+  computers, 0 .. 2**64-1) -- Programming Perl, 3rd ed.
+
+That has been the perl's notion of UTF-8 but official UTF-8 is more
+strict; Its ranges is much narrower (0 .. 10FFFF), some sequences are
+not allowed (i.e. Those used in the surrogate pair, 0xFFFE, et al).
+
+Now that is overruled by Larry Wall himself.
+
+  From: Larry Wall <larry@wall.org>
+  Date: December 04, 2004 11:51:58 JST
+  To: perl-unicode@perl.org
+  Subject: Re: Make Encode.pm support the real UTF-8
+  Message-Id: <20041204025158.GA28754@wall.org>
+  
+  On Fri, Dec 03, 2004 at 10:12:12PM +0000, Tim Bunce wrote:
+  : I've no problem with 'utf8' being perl's unrestricted uft8 encoding,
+  : but "UTF-8" is the name of the standard and should give the
+  : corresponding behaviour.
+  
+  For what it's worth, that's how I've always kept them straight in my
+  head.
+  
+  Also for what it's worth, Perl 6 will mostly default to strict but
+  make it easy to switch back to lax.
+  
+  Larry
+
+Do you copy?  As of Perl 5.8.7, B<UTF-8> means strict, official UTF-8
+while B<utf8> means liberal, lax, version thereof.  And Encode version
+2.10 or later thus groks the difference between C<UTF-8> and C<utf8>.
+
+  encode("utf8",  "\x{FFFF_FFFF}", 1); # okay
+  encode("UTF-8", "\x{FFFF_FFFF}", 1); # croaks
+
+C<UTF-8> in Encode is actually a canonical name for C<utf-8-strict>.
+Yes, the hyphen between "UTF" and "8" is important.  Without it Encode
+goes "liberal"
+
+  find_encoding("UTF-8")->name # is 'utf-8-strict'
+  find_encoding("utf-8")->name # ditto. names are case insensitive
+  find_encoding("utf_8")->name  # ditto. "_" are treated as "-"
+  find_encoding("UTF8")->name  # is 'utf8'.
+
+The UTF8 flag is internally called UTF8, without a hyphen. It indicates
+whether a string is internally encoded as utf8, also without a hypen.
+
 =head1 SEE ALSO
 
 L<Encode::Encoding>,
@@ -728,7 +938,7 @@ L<Encode::PerlIO>,
 L<encoding>,
 L<perlebcdic>,
 L<perlfunc/open>,
-L<perlunicode>,
+L<perlunicode>, L<perluniintro>, L<perlunifaq>, L<perlunitut>
 L<utf8>,
 the Perl Unicode Mailing List E<lt>perl-unicode@perl.orgE<gt>
 
@@ -739,4 +949,15 @@ by Dan Kogai E<lt>dankogai@dan.co.jpE<gt>.  See AUTHORS for a full
 list of people involved.  For any questions, use
 E<lt>perl-unicode@perl.orgE<gt> so we can all share.
 
+While Dan Kogai retains the copyright as a maintainer, the credit
+should go to all those involoved.  See AUTHORS for those submitted
+codes.
+
+=head1 COPYRIGHT
+
+Copyright 2002-2006 Dan Kogai E<lt>dankogai@dan.co.jpE<gt>
+
+This library is free software; you can redistribute it and/or modify
+it under the same terms as Perl itself.
+
 =cut