useless call
[lhc/web/wiklou.git] / includes / normal / UtfNormal.php
index b1664fa..c6183b5 100644 (file)
@@ -126,10 +126,24 @@ class UtfNormal {
         * @return string a clean, shiny, normalized UTF-8 string
         */
        function cleanUp( $string ) {
-               if( UtfNormal::quickIsNFCVerify( $string ) )
+               if( NORMALIZE_ICU ) {
+                       # We exclude a few chars that ICU would not.
+                       $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 );
+                       
+                       # 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", UNORM_NFC ), "\x01" );
+               } elseif( UtfNormal::quickIsNFCVerify( $string ) ) {
+                       # Side effect -- $string has had UTF-8 errors cleaned up.
                        return $string;
-               else
+               } else {
                        return UtfNormal::NFC( $string );
+               }
        }
 
        /**
@@ -255,112 +269,214 @@ class UtfNormal {
         * Returns true if the string is _definitely_ in NFC.
         * Returns false if not or uncertain.
         * @param string $string a UTF-8 string, altered on output to be valid UTF-8 safe for XML.
-        * @return bool
         */
        function quickIsNFCVerify( &$string ) {
+               # Screen out some characters that eg won't be allowed in XML
+               $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;
-               $len = strlen( $string );
-               $out = '';
-               $state = UTF8_HEAD;
-               $looksNormal = true;
+               static $checkit = null, $tailBytes = null, $utfCheckOrCombining = null;
+               if( !isset( $checkit ) ) {
+                       # Load/build some scary lookup tables...
+                       UtfNormal::loadData();
+                       global $utfCheckNFC, $utfCombiningClass;
+                       
+                       $utfCheckOrCombining = array_merge( $utfCheckNFC, $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 ) {
+                                       $remaining = 0;
+                               } elseif( $n < 0xe0 ) {
+                                       $remaining = 1;
+                               } elseif( $n < 0xf0 ) {
+                                       $remaining = 2;
+                               } elseif( $n < 0xf8 ) {
+                                       $remaining = 3;
+                               } elseif( $n < 0xfc ) {
+                                       $remaining = 4;
+                               } elseif( $n < 0xfe ) {
+                                       $remaining = 5;
+                               } else {
+                                       $remaining = 0;
+                               }
+                               $tailBytes[chr($n)] = $remaining;
+                       }
+               }
                
-               $rep = false;
-               $head = 0;
-               for( $i = 0; $i < $len; $i++ ) {
-                       $c = $string{$i};
-                       $n = ord( $c );
-                       if( $state == UTF8_TAIL ) {
-                               if( $n >= 0x80 && $n < 0xc0 ) {
-                                       $sequence .= $c;
-                                       if( --$remaining == 0 ) {
-                                               if( $head < 0xc2 || $head == 0xed || $head == 0xe0 || $head > 0xee ) {
-                                                       if( ( $sequence >= UTF8_SURROGATE_FIRST
-                                                                       && $sequence <= UTF8_SURROGATE_LAST)
-                                                               || ($head == 0xc0 && $sequence <= UTF8_OVERLONG_A)
-                                                               || ($head == 0xc1 && $sequence <= UTF8_OVERLONG_A)
-                                                               || ($head == 0xe0 && $sequence <= UTF8_OVERLONG_B)
-                                                               || ($head == 0xef && 
-                                                                       ($sequence >= UTF8_FDD0 && $sequence <= UTF8_FDEF)
-                                                                       || ($sequence == UTF8_FFFE)
+               # Chop the text into pure-ASCII and non-ASCII areas;
+               # large ASCII parts can be handled much more quickly.
+               # Don't chop up Unicode areas for punctuation, though,
+               # that wastes energy.
+               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 ) {
+                       $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;
+                       }
+                       
+                       # 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 = '';
+                       $len = $chunk + 1; # Counting down is faster. I'm *so* sorry.
+                       
+                       for( $i = -1; --$len; ) {
+                               if( $remaining = $tailBytes[$c = $str{++$i}] ) {
+                                       # 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;
+                                                               ++$len;
+                                                               continue 2;
+                                                       }
+                                               }
+                                       } while( --$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 && $sequence <= UTF8_OVERLONG_C)
-                                                               || ($sequence > UTF8_MAX) ) {
-                                                               $out .= UTF8_REPLACEMENT;
-                                                               $state = UTF8_HEAD;
+                                                               
+                                                               # Unicode has been limited to 21 bits; longer
+                                                               # sequences are not allowed.
+                                                               || ($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;
-                                               }
-                                               $out .= $sequence;
-                                               $state = UTF8_HEAD;
-                                               $head = 0;
                                        }
-                                       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 );
-                               $state = UTF8_HEAD;
-                               $out .= UTF8_REPLACEMENT;
-                       }
-                       if( $n < 0x20 ) {
-                               if( $n < 0x09 ) {
-                                       $out .= UTF8_REPLACEMENT;
-                               } elseif( $n == 0x0a ) {
-                                       $out .= $c;
-                               } elseif( $n < 0x0d ) {
-                                       $out .= UTF8_REPLACEMENT;
-                               } elseif( $n == 0x0d ) {
-                                       # Strip \r silently
+                                       
+                                       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" ) {
+                                       # ASCII byte.
+                                       $head = '';
+                               } elseif( $c < "\xc0" ) {
+                                       # Illegal tail bytes
+                                       if( $head == '' ) {
+                                               # 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 = '';
                                }
-                       } elseif( $n < 0x80 ) {
-                               # Friendly ASCII chars.
-                               $out .= $c;
-                       } elseif( $n < 0xc0 ) {
-                               # illegal tail bytes or head byte of overlong sequence
-                               if( $head == 0 ) $out .= UTF8_REPLACEMENT;
-                       } elseif( $n < 0xe0 ) {
-                               $state = UTF8_TAIL;
-                               $remaining = 1;
-                               $sequence = $c;
-                               $head = $n;
-                       } elseif( $n < 0xf0 ) {
-                               $state = UTF8_TAIL;
-                               $remaining = 2;
-                               $sequence = $c;
-                               $head = $n;
-                       } elseif( $n < 0xf8 ) {
-                               $state = UTF8_TAIL;
-                               $remaining = 3;
-                               $sequence = $c;
-                               $head = $n;
-                       } elseif( $n < 0xfc ) {
-                               $state = UTF8_TAIL;
-                               $remaining = 4;
-                               $sequence = $c;
-                               $head = $n;
-                       } elseif( $n < 0xfe ) {
-                               $state = UTF8_TAIL;
-                               $remaining = 5;
-                               $sequence = $c;
-                               $head = $n;
-                       } else {
-                               $out .= UTF8_REPLACEMENT;
                        }
+                       $base += $chunk;
                }
-               if( $state == UTF8_TAIL ) {
-                       $out .= UTF8_REPLACEMENT;
+               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;
        }
        
@@ -417,11 +533,11 @@ class UtfNormal {
         * (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
+        * @param string $string Valid UTF-8 string
+        * @param array $map hash of expanded decomposition map
         * @return string a UTF-8 string decomposed, not yet normalized (needs sorting)
         */
-       function fastDecompose( &$string, &$map ) {
+       function fastDecompose( $string, &$map ) {
                UtfNormal::loadData();
                $len = strlen( $string );
                $out = '';
@@ -445,6 +561,7 @@ class UtfNormal {
                        }
                        if( isset( $map[$c] ) ) {
                                $out .= $map[$c];
+                               continue;
                        } else {
                                if( $c >= UTF8_HANGUL_FIRST && $c <= UTF8_HANGUL_LAST ) {
                                        # Decompose a hangul syllable into jamo;
@@ -456,8 +573,8 @@ class UtfNormal {
                                                 | (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 ) {
@@ -465,10 +582,10 @@ class UtfNormal {
                                        } elseif( $t ) {
                                                $out .= "\xe1\x86" . chr( 0xa7 + $t );
                                        }
-                               } else {
-                                       $out .= $c;
+                                       continue;
                                }
                        }
+                       $out .= $c;
                }
                return $out;
        }
@@ -535,6 +652,7 @@ class UtfNormal {
                $len = strlen( $string );
                $out = '';
                $lastClass = -1;
+               $lastHangul = 0;
                $startChar = '';
                $combining = '';
                $x1 = ord(substr(UTF8_HANGUL_VBASE,0,1));
@@ -575,6 +693,7 @@ class UtfNormal {
                                                $combining .= $c;
                                        }
                                        $lastClass = $class;
+                                       $lastHangul = 0;
                                        continue;
                                }
                        }
@@ -582,6 +701,7 @@ class UtfNormal {
                        if( $lastClass == 0 ) {
                                if( isset( $utfCanonicalComp[$pair] ) ) {
                                        $startChar = $utfCanonicalComp[$pair];
+                                       $lastHangul = 0;
                                        continue;
                                }
                                if( $n >= $x1 && $n <= $x2 ) {
@@ -609,11 +729,13 @@ class UtfNormal {
                                                $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);
@@ -632,6 +754,9 @@ class UtfNormal {
                                                        $startChar{1} = chr( $mid );
                                                }
                                                $startChar{2} = chr( $tail );
+                                               
+                                               # If there's another jamo char after this, *don't* try to merge it.
+                                               $lastHangul = 1;
                                                continue;
                                        }
                                }
@@ -641,6 +766,7 @@ class UtfNormal {
                        $startChar = $c;
                        $combining = '';
                        $lastClass = 0;
+                       $lastHangul = 0;
                }
                $out .= $startChar . $combining;
                return $out;