Merge "Follow-up I0b781c11 (2a55449): use User::getAutomaticGroups()."
[lhc/web/wiklou.git] / includes / normal / UtfNormal.php
index 283fa73..08f85bd 100644 (file)
@@ -1,21 +1,35 @@
 <?php
-# Copyright (C) 2004 Brion Vibber <brion@pobox.com>
-# http://www.mediawiki.org/
-# 
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or 
-# (at your option) any later version.
-# 
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
-# GNU General Public License for more details.
-# 
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write to the Free Software Foundation, Inc.,
-# 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
-# http://www.gnu.org/copyleft/gpl.html
+/**
+ * Unicode normalization routines
+ *
+ * Copyright © 2004 Brion Vibber <brion@pobox.com>
+ * http://www.mediawiki.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @ingroup UtfNormal
+ */
+
+/**
+ * @defgroup UtfNormal UtfNormal
+ */
+
+define( 'NORMALIZE_ICU', function_exists( 'utf8_normalize' ) );
+define( 'NORMALIZE_INTL', function_exists( 'normalizer_normalize' ) );
 
 /**
  * Unicode normalization routines for working with UTF-8 strings.
  *
  * See description of forms at http://www.unicode.org/reports/tr15/
  *
- * @package UtfNormal
+ * @ingroup UtfNormal
  */
+class UtfNormal {
+       /**
+        * For using the ICU wrapper
+        */
+       const UNORM_NONE = 1;
+       const UNORM_NFD  = 2;
+       const UNORM_NFKD = 3;
+       const UNORM_NFC  = 4;
+       const UNORM_NFKC = 5;
+       const UNORM_FCD  = 6;
+       const UNORM_DEFAULT = self::UNORM_NFC;
 
-/** */
-require_once 'UtfNormalUtil.php';
-
-global $utfCombiningClass, $utfCanonicalComp, $utfCanonicalDecomp;
-$utfCombiningClass = NULL;
-$utfCanonicalComp = NULL;
-$utfCanonicalDecomp = NULL;
-
-# Load compatibility decompositions on demand if they are needed.
-global $utfCompatibilityDecomp;
-$utfCompatibilityDecomp = NULL;
-
-define( 'UNICODE_HANGUL_FIRST', 0xac00 );
-define( 'UNICODE_HANGUL_LAST',  0xd7a3 );
-
-define( 'UNICODE_HANGUL_LBASE', 0x1100 );
-define( 'UNICODE_HANGUL_VBASE', 0x1161 );
-define( 'UNICODE_HANGUL_TBASE', 0x11a7 );
-
-define( 'UNICODE_HANGUL_LCOUNT', 19 );
-define( 'UNICODE_HANGUL_VCOUNT', 21 );
-define( 'UNICODE_HANGUL_TCOUNT', 28 );
-define( 'UNICODE_HANGUL_NCOUNT', UNICODE_HANGUL_VCOUNT * UNICODE_HANGUL_TCOUNT );
-
-define( 'UNICODE_HANGUL_LEND', UNICODE_HANGUL_LBASE + UNICODE_HANGUL_LCOUNT - 1 );
-define( 'UNICODE_HANGUL_VEND', UNICODE_HANGUL_VBASE + UNICODE_HANGUL_VCOUNT - 1 );
-define( 'UNICODE_HANGUL_TEND', UNICODE_HANGUL_TBASE + UNICODE_HANGUL_TCOUNT - 1 );
-
-define( 'UNICODE_SURROGATE_FIRST', 0xd800 );
-define( 'UNICODE_SURROGATE_LAST', 0xdfff );
-define( 'UNICODE_MAX', 0x10ffff );
-define( 'UNICODE_REPLACEMENT', 0xfffd );
-
-
-define( 'UTF8_HANGUL_FIRST', codepointToUtf8( UNICODE_HANGUL_FIRST ) );
-define( 'UTF8_HANGUL_LAST', codepointToUtf8( UNICODE_HANGUL_LAST ) );
-
-define( 'UTF8_HANGUL_LBASE', codepointToUtf8( UNICODE_HANGUL_LBASE ) );
-define( 'UTF8_HANGUL_VBASE', codepointToUtf8( UNICODE_HANGUL_VBASE ) );
-define( 'UTF8_HANGUL_TBASE', codepointToUtf8( UNICODE_HANGUL_TBASE ) );
-
-define( 'UTF8_HANGUL_LEND', codepointToUtf8( UNICODE_HANGUL_LEND ) );
-define( 'UTF8_HANGUL_VEND', codepointToUtf8( UNICODE_HANGUL_VEND ) );
-define( 'UTF8_HANGUL_TEND', codepointToUtf8( UNICODE_HANGUL_TEND ) );
-
-define( 'UTF8_SURROGATE_FIRST', codepointToUtf8( UNICODE_SURROGATE_FIRST ) );
-define( 'UTF8_SURROGATE_LAST', codepointToUtf8( UNICODE_SURROGATE_LAST ) );
-define( 'UTF8_MAX', codepointToUtf8( UNICODE_MAX ) );
-define( 'UTF8_REPLACEMENT', codepointToUtf8( UNICODE_REPLACEMENT ) );
-#define( 'UTF8_REPLACEMENT', '!' );
-
-define( 'UTF8_OVERLONG_A', "\xc1\xbf" );
-define( 'UTF8_OVERLONG_B', "\xe0\x9f\xbf" );
-define( 'UTF8_OVERLONG_C', "\xf0\x8f\xbf\xbf" );
-
-# These two ranges are illegal
-define( 'UTF8_FDD0', codepointToUtf8( 0xfdd0 ) );
-define( 'UTF8_FDEF', codepointToUtf8( 0xfdef ) );
-define( 'UTF8_FFFE', codepointToUtf8( 0xfffe ) );
-define( 'UTF8_FFFF', codepointToUtf8( 0xffff ) );
+       static $utfCombiningClass = null;
+       static $utfCanonicalComp = null;
+       static $utfCanonicalDecomp = null;
 
-define( 'UTF8_HEAD', false );
-define( 'UTF8_TAIL', true );
+       # Load compatibility decompositions on demand if they are needed.
+       static $utfCompatibilityDecomp = null;
 
+       static $utfCheckNFC;
 
-/**
- * For using the ICU wrapper
- */
-define( 'UNORM_NONE', 1 );
-define( 'UNORM_NFD',  2 );
-define( 'UNORM_NFKD', 3 );
-define( 'UNORM_NFC',  4 );
-define( 'UNORM_DEFAULT', UNORM_NFC );
-define( 'UNORM_NFKC', 5 );
-define( 'UNORM_FCD',  6 );
-
-define( 'NORMALIZE_ICU', function_exists( 'utf8_normalize' ) );
-
-/**
- *
- * @package MediaWiki
- */
-class UtfNormal {
        /**
         * The ultimate convenience function! Clean up invalid UTF-8 sequences,
         * and convert to normal form C, canonical composition.
@@ -122,14 +73,40 @@ class UtfNormal {
         * Fast return for pure ASCII strings; some lesser optimizations for
         * strings containing only known-good characters. Not as fast as toNFC().
         *
-        * @param string $string a UTF-8 string
+        * @param $string String: a UTF-8 string
         * @return string a clean, shiny, normalized UTF-8 string
         */
-       function cleanUp( $string ) {
-               if( UtfNormal::quickIsNFCVerify( $string ) )
+       static function cleanUp( $string ) {
+               if( NORMALIZE_ICU ) {
+                       $string = self::replaceForNativeNormalize( $string );
+
+                       # UnicodeString constructor fails if the string ends with a
+                       # head byte. Add a junk char at the end, we'll strip it off.
+                       return rtrim( utf8_normalize( $string . "\x01", self::UNORM_NFC ), "\x01" );
+               } elseif( NORMALIZE_INTL ) {
+                       $string = self::replaceForNativeNormalize( $string );
+                       $norm = normalizer_normalize( $string, Normalizer::FORM_C );
+                       if( $norm === null || $norm === false ) {
+                               # normalizer_normalize will either return false or null
+                               # (depending on which doc you read) if invalid utf8 string.
+                               # quickIsNFCVerify cleans up invalid sequences.
+
+                               if( UtfNormal::quickIsNFCVerify( $string ) ) {
+                                       # if that's true, the string is actually already normal.
+                                       return $string;
+                               } else {
+                                       # Now we are valid but non-normal
+                                       return normalizer_normalize( $string, Normalizer::FORM_C );
+                               }
+                       } else {
+                               return $norm;
+                       }
+               } elseif( UtfNormal::quickIsNFCVerify( $string ) ) {
+                       # Side effect -- $string has had UTF-8 errors cleaned up.
                        return $string;
-               else
+               } else {
                        return UtfNormal::NFC( $string );
+               }
        }
 
        /**
@@ -137,95 +114,101 @@ class UtfNormal {
         * Fast return for pure ASCII strings; some lesser optimizations for
         * strings containing only known-good characters.
         *
-        * @param string $string a valid UTF-8 string. Input is not validated.
+        * @param $string String: a valid UTF-8 string. Input is not validated.
         * @return string a UTF-8 string in normal form C
         */
-       function toNFC( $string ) {
-               if( NORMALIZE_ICU )
-                       return utf8_normalize( $string, UNORM_NFC );
+       static function toNFC( $string ) {
+               if( NORMALIZE_INTL )
+                       return normalizer_normalize( $string, Normalizer::FORM_C );
+               elseif( NORMALIZE_ICU )
+                       return utf8_normalize( $string, self::UNORM_NFC );
                elseif( UtfNormal::quickIsNFC( $string ) )
                        return $string;
                else
                        return UtfNormal::NFC( $string );
        }
-       
+
        /**
         * Convert a UTF-8 string to normal form D, canonical decomposition.
         * Fast return for pure ASCII strings.
         *
-        * @param string $string a valid UTF-8 string. Input is not validated.
+        * @param $string String: a valid UTF-8 string. Input is not validated.
         * @return string a UTF-8 string in normal form D
         */
-       function toNFD( $string ) {
-               if( NORMALIZE_ICU )
-                       return utf8_normalize( $string, UNORM_NFD );
+       static function toNFD( $string ) {
+               if( NORMALIZE_INTL )
+                       return normalizer_normalize( $string, Normalizer::FORM_D );
+               elseif( NORMALIZE_ICU )
+                       return utf8_normalize( $string, self::UNORM_NFD );
                elseif( preg_match( '/[\x80-\xff]/', $string ) )
                        return UtfNormal::NFD( $string );
                else
                        return $string;
        }
-       
+
        /**
         * Convert a UTF-8 string to normal form KC, compatibility composition.
         * This may cause irreversible information loss, use judiciously.
         * Fast return for pure ASCII strings.
         *
-        * @param string $string a valid UTF-8 string. Input is not validated.
+        * @param $string String: a valid UTF-8 string. Input is not validated.
         * @return string a UTF-8 string in normal form KC
         */
-       function toNFKC( $string ) {
-               if( NORMALIZE_ICU )
-                       return utf8_normalize( $string, UNORM_NFKC );
+       static function toNFKC( $string ) {
+               if( NORMALIZE_INTL )
+                       return normalizer_normalize( $string, Normalizer::FORM_KC );
+               elseif( NORMALIZE_ICU )
+                       return utf8_normalize( $string, self::UNORM_NFKC );
                elseif( preg_match( '/[\x80-\xff]/', $string ) )
                        return UtfNormal::NFKC( $string );
                else
                        return $string;
        }
-       
+
        /**
         * Convert a UTF-8 string to normal form KD, compatibility decomposition.
         * This may cause irreversible information loss, use judiciously.
         * Fast return for pure ASCII strings.
         *
-        * @param string $string a valid UTF-8 string. Input is not validated.
+        * @param $string String: a valid UTF-8 string. Input is not validated.
         * @return string a UTF-8 string in normal form KD
         */
-       function toNFKD( $string ) {
-               if( NORMALIZE_ICU )
-                       return utf8_normalize( $string, UNORM_NFKD );
+       static function toNFKD( $string ) {
+               if( NORMALIZE_INTL )
+                       return normalizer_normalize( $string, Normalizer::FORM_KD );
+               elseif( NORMALIZE_ICU )
+                       return utf8_normalize( $string, self::UNORM_NFKD );
                elseif( preg_match( '/[\x80-\xff]/', $string ) )
                        return UtfNormal::NFKD( $string );
                else
                        return $string;
        }
-       
+
        /**
         * Load the basic composition data if necessary
-        * @access private
+        * @private
         */
-       function loadData() {
-               global $utfCombiningClass, $utfCanonicalComp, $utfCanonicalDecomp;
-               if( !isset( $utfCombiningClass ) ) {
-                       require_once( 'UtfNormalData.inc' );
+       static function loadData() {
+               if( !isset( self::$utfCombiningClass ) ) {
+                       require_once( __DIR__ . '/UtfNormalData.inc' );
                }
        }
-       
+
        /**
         * Returns true if the string is _definitely_ in NFC.
         * Returns false if not or uncertain.
-        * @param string $string a valid UTF-8 string. Input is not validated.
+        * @param $string String: a valid UTF-8 string. Input is not validated.
         * @return bool
         */
-       function quickIsNFC( $string ) {
+       static function quickIsNFC( $string ) {
                # ASCII is always valid NFC!
                # If it's pure ASCII, let it through.
                if( !preg_match( '/[\x80-\xff]/', $string ) ) return true;
-               
+
                UtfNormal::loadData();
-               global $utfCheckNFC, $utfCombiningClass;
                $len = strlen( $string );
                for( $i = 0; $i < $len; $i++ ) {
-                       $c = $string{$i};
+                       $c = $string[$i];
                        $n = ord( $c );
                        if( $n < 0x80 ) {
                                continue;
@@ -239,11 +222,11 @@ class UtfNormal {
                                $c = substr( $string, $i, 2 );
                                $i++;
                        }
-                       if( isset( $utfCheckNFC[$c] ) ) {
+                       if( isset( self::$utfCheckNFC[$c] ) ) {
                                # If it's NO or MAYBE, bail and do the slow check.
                                return false;
                        }
-                       if( isset( $utfCombiningClass[$c] ) ) {
+                       if( isset( self::$utfCombiningClass[$c] ) ) {
                                # Combining character? We might have to do sorting, at least.
                                return false;
                        }
@@ -254,26 +237,33 @@ class UtfNormal {
        /**
         * Returns true if the string is _definitely_ in NFC.
         * Returns false if not or uncertain.
-        * @param string $string a UTF-8 string, altered on output to be valid UTF-8 safe for XML.
+        * @param $string String: a UTF-8 string, altered on output to be valid UTF-8 safe for XML.
+        * @return bool
         */
-       function quickIsNFCVerify( &$string ) {
+       static function quickIsNFCVerify( &$string ) {
                # Screen out some characters that eg won't be allowed in XML
-               preg_replace( '/[\x00-\x08\x0b\x0c\x0e-\x1f]/', UTF8_REPLACEMENT, $string );
-               
+               $string = preg_replace( '/[\x00-\x08\x0b\x0c\x0e-\x1f]/', UTF8_REPLACEMENT, $string );
+
                # ASCII is always valid NFC!
+               # If we're only ever given plain ASCII, we can avoid the overhead
+               # of initializing the decomposition tables by skipping out early.
                if( !preg_match( '/[\x80-\xff]/', $string ) ) return true;
-               
-               UtfNormal::loadData();
-               global $utfCheckNFC, $utfCombiningClass;
-               
-               static $checkit = null, $tailBytes = null;
+
+               static $checkit = null, $tailBytes = null, $utfCheckOrCombining = null;
                if( !isset( $checkit ) ) {
+                       # Load/build some scary lookup tables...
+                       UtfNormal::loadData();
+
+                       $utfCheckOrCombining = array_merge( self::$utfCheckNFC, self::$utfCombiningClass );
+
                        # Head bytes for sequences which we should do further validity checks
                        $checkit = array_flip( array_map( 'chr',
                                        array( 0xc0, 0xc1, 0xe0, 0xed, 0xef,
                                                   0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
                                                   0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff ) ) );
-                       
+
+                       # Each UTF-8 head byte is followed by a certain
+                       # number of tail bytes.
                        $tailBytes = array();
                        for( $n = 0; $n < 256; $n++ ) {
                                if( $n < 0xc0 ) {
@@ -294,158 +284,235 @@ class UtfNormal {
                                $tailBytes[chr($n)] = $remaining;
                        }
                }
-               
+
                # Chop the text into pure-ASCII and non-ASCII areas;
                # large ASCII parts can be handled much more quickly.
-               # Don't chop up for little newlines or spaces, though,
+               # Don't chop up Unicode areas for punctuation, though,
                # that wastes energy.
-               preg_match_all( '/([\x00-\x7f]+|[\x80-\xff][\x0a\x20\x80-\xff]*)/', $string, $matches );
-               
-               $out = '';
+               $matches = array();
+               preg_match_all(
+                       '/([\x00-\x7f]+|[\x80-\xff][\x00-\x40\x5b-\x5f\x7b-\xff]*)/',
+                       $string, $matches );
+
                $looksNormal = true;
+               $base = 0;
+               $replace = array();
                foreach( $matches[1] as $str ) {
-                       if( $str{0} < "\x80" ) {
-                               $out .= $str;
+                       $chunk = strlen( $str );
+
+                       if( $str[0] < "\x80" ) {
+                               # ASCII chunk: guaranteed to be valid UTF-8
+                               # and in normal form C, so skip over it.
+                               $base += $chunk;
                                continue;
                        }
-                       $len = strlen( $str );
-                       $tail = false;
+
+                       # We'll have to examine the chunk byte by byte to ensure
+                       # that it consists of valid UTF-8 sequences, and to see
+                       # if any of them might not be normalized.
+                       #
+                       # Since PHP is not the fastest language on earth, some of
+                       # this code is a little ugly with inner loop optimizations.
+
                        $head = '';
-                       
-                       for( $i = 0; $i < $len; $i++ ) {
-                               $c = $str{$i};
-                               if( $tail ) {
-                                       if( $c >= "\x80" && $c < "\xc0" ) {
-                                               $sequence .= $c;
-                                               if( --$remaining ) {
-                                                       # Keep adding bytes...
-                                                       continue;
+                       $len = $chunk + 1; # Counting down is faster. I'm *so* sorry.
+
+                       for( $i = -1; --$len; ) {
+                               $remaining = $tailBytes[$c = $str[++$i]];
+                               if( $remaining ) {
+                                       # UTF-8 head byte!
+                                       $sequence = $head = $c;
+                                       do {
+                                               # Look for the defined number of tail bytes...
+                                               if( --$len && ( $c = $str[++$i] ) >= "\x80" && $c < "\xc0" ) {
+                                                       # Legal tail bytes are nice.
+                                                       $sequence .= $c;
+                                               } else {
+                                                       if( 0 == $len ) {
+                                                               # Premature end of string!
+                                                               # Drop a replacement character into output to
+                                                               # represent the invalid UTF-8 sequence.
+                                                               $replace[] = array( UTF8_REPLACEMENT,
+                                                                                                       $base + $i + 1 - strlen( $sequence ),
+                                                                                                       strlen( $sequence ) );
+                                                               break 2;
+                                                       } else {
+                                                               # Illegal tail byte; abandon the sequence.
+                                                               $replace[] = array( UTF8_REPLACEMENT,
+                                                                                                       $base + $i - strlen( $sequence ),
+                                                                                                       strlen( $sequence ) );
+                                                               # Back up and reprocess this byte; it may itself
+                                                               # be a legal ASCII or UTF-8 sequence head.
+                                                               --$i;
+                                                               ++$len;
+                                                               continue 2;
+                                                       }
                                                }
-       
-                                               if( isset( $checkit[$head] ) ) {
-                                                       # Do some more detailed validity checks, for
-                                                       # invalid characters and illegal sequences.
-                                                       $head = ord( $head );
-                                                       if( ( $head == 0xed && $sequence >= UTF8_SURROGATE_FIRST
-                                                                       && $sequence <= UTF8_SURROGATE_LAST)
-                                                               || ($head  < 0xc2 && $sequence <= UTF8_OVERLONG_A)
-                                                               || ($head == 0xe0 && $sequence <= UTF8_OVERLONG_B)
-                                                               || ($head == 0xef && 
-                                                                       ($sequence >= UTF8_FDD0 && $sequence <= UTF8_FDEF)
-                                                                       || ($sequence == UTF8_FFFE)
+                                       } while( --$remaining );
+
+                                       if( isset( $checkit[$head] ) ) {
+                                               # Do some more detailed validity checks, for
+                                               # invalid characters and illegal sequences.
+                                               if( $head == "\xed" ) {
+                                                       # 0xed is relatively frequent in Korean, which
+                                                       # abuts the surrogate area, so we're doing
+                                                       # this check separately to speed things up.
+
+                                                       if( $sequence >= UTF8_SURROGATE_FIRST ) {
+                                                               # Surrogates are legal only in UTF-16 code.
+                                                               # They are totally forbidden here in UTF-8
+                                                               # utopia.
+                                                               $replace[] = array( UTF8_REPLACEMENT,
+                                                                            $base + $i + 1 - strlen( $sequence ),
+                                                                            strlen( $sequence ) );
+                                                               $head = '';
+                                                               continue;
+                                                       }
+                                               } else {
+                                                       # Slower, but rarer checks...
+                                                       $n = ord( $head );
+                                                       if(
+                                                               # "Overlong sequences" are those that are syntactically
+                                                               # correct but use more UTF-8 bytes than are necessary to
+                                                               # encode a character. Naïve string comparisons can be
+                                                               # tricked into failing to see a match for an ASCII
+                                                               # character, for instance, which can be a security hole
+                                                               # if blacklist checks are being used.
+                                                              ($n  < 0xc2 && $sequence <= UTF8_OVERLONG_A)
+                                                               || ($n == 0xe0 && $sequence <= UTF8_OVERLONG_B)
+                                                               || ($n == 0xf0 && $sequence <= UTF8_OVERLONG_C)
+
+                                                               # U+FFFE and U+FFFF are explicitly forbidden in Unicode.
+                                                               || ($n == 0xef &&
+                                                                          ($sequence == UTF8_FFFE)
                                                                        || ($sequence == UTF8_FFFF) )
-                                                               || ($head == 0xf0 && $sequence <= UTF8_OVERLONG_C)
-                                                               || ($head >= 0xf0 && $sequence > UTF8_MAX) ) {
-                                                               $out .= UTF8_REPLACEMENT;
-                                                               $tail = false;
+
+                                                               # Unicode has been limited to 21 bits; longer
+                                                               # sequences are not allowed.
+                                                               || ($n >= 0xf0 && $sequence > UTF8_MAX) ) {
+
+                                                               $replace[] = array( UTF8_REPLACEMENT,
+                                                                                   $base + $i + 1 - strlen( $sequence ),
+                                                                                   strlen( $sequence ) );
+                                                               $head = '';
                                                                continue;
                                                        }
                                                }
-                                               
-                                               if( isset( $utfCheckNFC[$sequence] ) ||
-                                                       isset( $utfCombiningClass[$sequence] ) ) {
-                                                       # If it's NO or MAYBE, we'll have to do the slow check.
-                                                       $looksNormal = false;
-                                               }
-                                               
-                                               # The sequence is legal!
-                                               $out .= $sequence;
-                                               $tail = false;
-                                               $head = '';
-                                               continue;
                                        }
-                                       # Not a valid tail byte! DIscard the char we've been building.
-                                       #printf ("Invalid '%x' in tail with %d remaining bytes\n", $n, $remaining );
-                                       $tail = false;
-                                       $out .= UTF8_REPLACEMENT;
-                               }
-                               if( $remaining = $tailBytes[$c] ) {
-                                       $tail = true;
-                                       $sequence = $c;
-                                       $head = $c;
+
+                                       if( isset( $utfCheckOrCombining[$sequence] ) ) {
+                                               # If it's NO or MAYBE, we'll have to rip
+                                               # the string apart and put it back together.
+                                               # That's going to be mighty slow.
+                                               $looksNormal = false;
+                                       }
+
+                                       # The sequence is legal!
+                                       $head = '';
                                } elseif( $c < "\x80" ) {
-                                       $out .= $c;
+                                       # ASCII byte.
+                                       $head = '';
                                } elseif( $c < "\xc0" ) {
-                                       # illegal tail bytes or head byte of overlong sequence
+                                       # Illegal tail bytes
                                        if( $head == '' ) {
-                                               # Don't add if we're continuing a too-long sequence
-                                               $out .= UTF8_REPLACEMENT;
+                                               # Out of the blue!
+                                               $replace[] = array( UTF8_REPLACEMENT, $base + $i, 1 );
+                                       } else {
+                                               # Don't add if we're continuing a broken sequence;
+                                               # we already put a replacement character when we looked
+                                               # at the broken sequence.
+                                               $replace[] = array( '', $base + $i, 1 );
                                        }
                                } else {
-                                       $out .= UTF8_REPLACEMENT;
+                                       # Miscellaneous freaks.
+                                       $replace[] = array( UTF8_REPLACEMENT, $base + $i, 1 );
+                                       $head = '';
                                }
                        }
-                       if( $tail ) {
-                               $out .= UTF8_REPLACEMENT;
+                       $base += $chunk;
+               }
+               if( count( $replace ) ) {
+                       # There were illegal UTF-8 sequences we need to fix up.
+                       $out = '';
+                       $last = 0;
+                       foreach( $replace as $rep ) {
+                               list( $replacement, $start, $length ) = $rep;
+                               if( $last < $start ) {
+                                       $out .= substr( $string, $last, $start - $last );
+                               }
+                               $out .= $replacement;
+                               $last = $start + $length;
+                       }
+                       if( $last < strlen( $string ) ) {
+                               $out .= substr( $string, $last );
                        }
+                       $string = $out;
                }
-               $string = $out;
                return $looksNormal;
        }
-       
+
        # These take a string and run the normalization on them, without
        # checking for validity or any optimization etc. Input must be
        # VALID UTF-8!
        /**
-        * @param string $string
+        * @param $string string
         * @return string
-        * @access private
+        * @private
         */
-       function NFC( $string ) {
+       static function NFC( $string ) {
                return UtfNormal::fastCompose( UtfNormal::NFD( $string ) );
        }
-       
+
        /**
-        * @param string $string
+        * @param $string string
         * @return string
-        * @access private
+        * @private
         */
-       function NFD( $string ) {
+       static function NFD( $string ) {
                UtfNormal::loadData();
-               global $utfCanonicalDecomp;
+
                return UtfNormal::fastCombiningSort(
-                       UtfNormal::fastDecompose( $string, $utfCanonicalDecomp ) );
+                       UtfNormal::fastDecompose( $string, self::$utfCanonicalDecomp ) );
        }
-       
+
        /**
-        * @param string $string
+        * @param $string string
         * @return string
-        * @access private
+        * @private
         */
-       function NFKC( $string ) {
+       static function NFKC( $string ) {
                return UtfNormal::fastCompose( UtfNormal::NFKD( $string ) );
        }
-       
+
        /**
-        * @param string $string
+        * @param $string string
         * @return string
-        * @access private
+        * @private
         */
-       function NFKD( $string ) {
-               global $utfCompatibilityDecomp;
-               if( !isset( $utfCompatibilityDecomp ) ) {
+       static function NFKD( $string ) {
+               if( !isset( self::$utfCompatibilityDecomp ) ) {
                        require_once( 'UtfNormalDataK.inc' );
                }
-               return UtfNormal::fastCombiningSort(
-                       UtfNormal::fastDecompose( $string, $utfCompatibilityDecomp ) );
+               return self::fastCombiningSort(
+                       self::fastDecompose( $string, self::$utfCompatibilityDecomp ) );
        }
-       
-       
+
+
        /**
         * Perform decomposition of a UTF-8 string into either D or KD form
         * (depending on which decomposition map is passed to us).
         * Input is assumed to be *valid* UTF-8. Invalid code will break.
-        * @access private
-        * @param string $string Valid UTF-8 string
-        * @param array $map hash of expanded decomposition map
+        * @private
+        * @param $string String: valid UTF-8 string
+        * @param $map Array: hash of expanded decomposition map
         * @return string a UTF-8 string decomposed, not yet normalized (needs sorting)
         */
-       function fastDecompose( $string, &$map ) {
+       static function fastDecompose( $string, $map ) {
                UtfNormal::loadData();
                $len = strlen( $string );
                $out = '';
                for( $i = 0; $i < $len; $i++ ) {
-                       $c = $string{$i};
+                       $c = $string[$i];
                        $n = ord( $c );
                        if( $n < 0x80 ) {
                                # ASCII chars never decompose
@@ -472,12 +539,12 @@ class UtfNormal {
                                        # A lookup table would be slightly faster,
                                        # but adds a lot of memory & disk needs.
                                        #
-                                       $index = ( (ord( $c{0} ) & 0x0f) << 12
-                                                | (ord( $c{1} ) & 0x3f) <<  6
-                                                | (ord( $c{2} ) & 0x3f) )
+                                       $index = ( (ord( $c[0] ) & 0x0f) << 12
+                                                | (ord( $c[1] ) & 0x3f) <<  6
+                                                | (ord( $c[2] ) & 0x3f) )
                                               - UNICODE_HANGUL_FIRST;
-                                       $l = IntVal( $index / UNICODE_HANGUL_NCOUNT );
-                                       $v = IntVal( ($index % UNICODE_HANGUL_NCOUNT) / UNICODE_HANGUL_TCOUNT);
+                                       $l = intval( $index / UNICODE_HANGUL_NCOUNT );
+                                       $v = intval( ($index % UNICODE_HANGUL_NCOUNT) / UNICODE_HANGUL_TCOUNT);
                                        $t = $index % UNICODE_HANGUL_TCOUNT;
                                        $out .= "\xe1\x84" . chr( 0x80 + $l ) . "\xe1\x85" . chr( 0xa1 + $v );
                                        if( $t >= 25 ) {
@@ -496,19 +563,18 @@ class UtfNormal {
        /**
         * Sorts combining characters into canonical order. This is the
         * final step in creating decomposed normal forms D and KD.
-        * @access private
-        * @param string $string a valid, decomposed UTF-8 string. Input is not validated.
+        * @private
+        * @param $string String: a valid, decomposed UTF-8 string. Input is not validated.
         * @return string a UTF-8 string with combining characters sorted in canonical order
         */
-       function fastCombiningSort( $string ) {
+       static function fastCombiningSort( $string ) {
                UtfNormal::loadData();
-               global $utfCombiningClass;
                $len = strlen( $string );
                $out = '';
                $combiners = array();
                $lastClass = -1;
                for( $i = 0; $i < $len; $i++ ) {
-                       $c = $string{$i};
+                       $c = $string[$i];
                        $n = ord( $c );
                        if( $n >= 0x80 ) {
                                if( $n >= 0xf0 ) {
@@ -521,9 +587,13 @@ class UtfNormal {
                                        $c = substr( $string, $i, 2 );
                                        $i++;
                                }
-                               if( isset( $utfCombiningClass[$c] ) ) {
-                                       $lastClass = $utfCombiningClass[$c];
-                                       @$combiners[$lastClass] .= $c;
+                               if( isset( self::$utfCombiningClass[$c] ) ) {
+                                       $lastClass = self::$utfCombiningClass[$c];
+                                       if( isset( $combiners[$lastClass] ) ) {
+                                               $combiners[$lastClass] .= $c;
+                                       } else {
+                                               $combiners[$lastClass] = $c;
+                                       }
                                        continue;
                                }
                        }
@@ -545,22 +615,22 @@ class UtfNormal {
        /**
         * Produces canonically composed sequences, i.e. normal form C or KC.
         *
-        * @access private
-        * @param string $string a valid UTF-8 string in sorted normal form D or KD. Input is not validated.
+        * @private
+        * @param $string String: a valid UTF-8 string in sorted normal form D or KD. Input is not validated.
         * @return string a UTF-8 string with canonical precomposed characters used where possible
         */
-       function fastCompose( $string ) {
+       static function fastCompose( $string ) {
                UtfNormal::loadData();
-               global $utfCanonicalComp, $utfCombiningClass;
                $len = strlen( $string );
                $out = '';
                $lastClass = -1;
+               $lastHangul = 0;
                $startChar = '';
                $combining = '';
                $x1 = ord(substr(UTF8_HANGUL_VBASE,0,1));
                $x2 = ord(substr(UTF8_HANGUL_TEND,0,1));
                for( $i = 0; $i < $len; $i++ ) {
-                       $c = $string{$i};
+                       $c = $string[$i];
                        $n = ord( $c );
                        if( $n < 0x80 ) {
                                # No combining characters here...
@@ -582,26 +652,28 @@ class UtfNormal {
                        }
                        $pair = $startChar . $c;
                        if( $n > 0x80 ) {
-                               if( isset( $utfCombiningClass[$c] ) ) {
+                               if( isset( self::$utfCombiningClass[$c] ) ) {
                                        # A combining char; see what we can do with it
-                                       $class = $utfCombiningClass[$c];
+                                       $class = self::$utfCombiningClass[$c];
                                        if( !empty( $startChar ) &&
                                                $lastClass < $class &&
                                                $class > 0 &&
-                                               isset( $utfCanonicalComp[$pair] ) ) {
-                                               $startChar = $utfCanonicalComp[$pair];
+                                               isset( self::$utfCanonicalComp[$pair] ) ) {
+                                               $startChar = self::$utfCanonicalComp[$pair];
                                                $class = 0;
                                        } else {
                                                $combining .= $c;
                                        }
                                        $lastClass = $class;
+                                       $lastHangul = 0;
                                        continue;
                                }
                        }
                        # New start char
                        if( $lastClass == 0 ) {
-                               if( isset( $utfCanonicalComp[$pair] ) ) {
-                                       $startChar = $utfCanonicalComp[$pair];
+                               if( isset( self::$utfCanonicalComp[$pair] ) ) {
+                                       $startChar = self::$utfCanonicalComp[$pair];
+                                       $lastHangul = 0;
                                        continue;
                                }
                                if( $n >= $x1 && $n <= $x2 ) {
@@ -618,40 +690,45 @@ class UtfNormal {
                                                #
                                                #$lIndex = utf8ToCodepoint( $startChar ) - UNICODE_HANGUL_LBASE;
                                                #$vIndex = utf8ToCodepoint( $c ) - UNICODE_HANGUL_VBASE;
-                                               $lIndex = ord( $startChar{2} ) - 0x80;
-                                               $vIndex = ord( $c{2}         ) - 0xa1;
+                                               $lIndex = ord( $startChar[2] ) - 0x80;
+                                               $vIndex = ord( $c[2]         ) - 0xa1;
 
                                                $hangulPoint = UNICODE_HANGUL_FIRST +
                                                        UNICODE_HANGUL_TCOUNT *
                                                        (UNICODE_HANGUL_VCOUNT * $lIndex + $vIndex);
-                                               
+
                                                # Hardcode the limited-range UTF-8 conversion:
                                                $startChar = chr( $hangulPoint >> 12 & 0x0f | 0xe0 ) .
                                                                         chr( $hangulPoint >>  6 & 0x3f | 0x80 ) .
                                                                         chr( $hangulPoint       & 0x3f | 0x80 );
+                                               $lastHangul = 0;
                                                continue;
                                        } elseif( $c >= UTF8_HANGUL_TBASE &&
                                                          $c <= UTF8_HANGUL_TEND &&
                                                          $startChar >= UTF8_HANGUL_FIRST &&
-                                                         $startChar <= UTF8_HANGUL_LAST ) {
+                                                         $startChar <= UTF8_HANGUL_LAST &&
+                                                         !$lastHangul ) {
                                                # $tIndex = utf8ToCodepoint( $c ) - UNICODE_HANGUL_TBASE;
-                                               $tIndex = ord( $c{2} ) - 0xa7;
-                                               if( $tIndex < 0 ) $tIndex = ord( $c{2} ) - 0x80 + (0x11c0 - 0x11a7);
-                                               
+                                               $tIndex = ord( $c[2] ) - 0xa7;
+                                               if( $tIndex < 0 ) $tIndex = ord( $c[2] ) - 0x80 + (0x11c0 - 0x11a7);
+
                                                # Increment the code point by $tIndex, without
                                                # the function overhead of decoding and recoding UTF-8
                                                #
-                                               $tail = ord( $startChar{2} ) + $tIndex;
+                                               $tail = ord( $startChar[2] ) + $tIndex;
                                                if( $tail > 0xbf ) {
                                                        $tail -= 0x40;
-                                                       $mid = ord( $startChar{1} ) + 1;
+                                                       $mid = ord( $startChar[1] ) + 1;
                                                        if( $mid > 0xbf ) {
-                                                               $startChar{0} = chr( ord( $startChar{0} ) + 1 );
+                                                               $startChar[0] = chr( ord( $startChar[0] ) + 1 );
                                                                $mid -= 0x40;
                                                        }
-                                                       $startChar{1} = chr( $mid );
+                                                       $startChar[1] = chr( $mid );
                                                }
-                                               $startChar{2} = chr( $tail );
+                                               $startChar[2] = chr( $tail );
+
+                                               # If there's another jamo char after this, *don't* try to merge it.
+                                               $lastHangul = 1;
                                                continue;
                                        }
                                }
@@ -661,25 +738,40 @@ class UtfNormal {
                        $startChar = $c;
                        $combining = '';
                        $lastClass = 0;
+                       $lastHangul = 0;
                }
                $out .= $startChar . $combining;
                return $out;
        }
-       
+
        /**
         * This is just used for the benchmark, comparing how long it takes to
         * interate through a string without really doing anything of substance.
-        * @param string $string
+        * @param $string string
         * @return string
         */
-       function placebo( $string ) {
+       static function placebo( $string ) {
                $len = strlen( $string );
                $out = '';
                for( $i = 0; $i < $len; $i++ ) {
-                       $out .= $string{$i};
+                       $out .= $string[$i];
                }
                return $out;
        }
+       /**
+        * Function to replace some characters that we don't want
+        * but most of the native normalize functions keep.
+        *
+        * @param $string String The string
+        * @return String String with the character codes replaced.
+        */
+       private static function replaceForNativeNormalize( $string ) { 
+               $string = preg_replace(
+                       '/[\x00-\x08\x0b\x0c\x0e-\x1f]/',
+                       UTF8_REPLACEMENT,
+                       $string );
+               $string = str_replace( UTF8_FFFE, UTF8_REPLACEMENT, $string );
+               $string = str_replace( UTF8_FFFF, UTF8_REPLACEMENT, $string );
+               return $string;
+       }
 }
-
-?>