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12 files changed, 1416 insertions, 0 deletions

diff --git a/www/wiki/includes/collation/AbkhazUppercaseCollation.php b/www/wiki/includes/collation/AbkhazUppercaseCollation.php
new file mode 100644
index 00000000..e0ea237f
--- /dev/null
+++ b/www/wiki/includes/collation/AbkhazUppercaseCollation.php
@@ -0,0 +1,93 @@
+<?php
+/**
+ * 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
+ *
+ * @since 1.31
+ *
+ * @file
+ */
+
+class AbkhazUppercaseCollation extends CustomUppercaseCollation {
+
+	public function __construct() {
+		parent::__construct( [
+			'А',
+			'Б',
+			'В',
+			'Г',
+			'Гь',
+			'Гә',
+			'Ҕ',
+			'Ҕь',
+			'Ҕә',
+			'Д',
+			'Дә',
+			'Е',
+			'Ж',
+			'Жь',
+			'Жә',
+			'З',
+			'Ӡ',
+			'Ӡә',
+			'И',
+			'К',
+			'Кь',
+			'Кә',
+			'Қ',
+			'Қь',
+			'Қә',
+			'Ҟ',
+			'Ҟь',
+			'Ҟә',
+			'Л',
+			'М',
+			'Н',
+			'О',
+			'П',
+			'Ҧ',
+			'Р',
+			'С',
+			'Т',
+			'Тә',
+			'Ҭ',
+			'Ҭә',
+			'У',
+			'Ф',
+			'Х',
+			'Хь',
+			'Хә',
+			'Ҳ',
+			'Ҳә',
+			'Ц',
+			'Цә',
+			'Ҵ',
+			'Ҵә',
+			'Ч',
+			'Ҷ',
+			'Ҽ',
+			'Ҿ',
+			'Ш',
+			'Шь',
+			'Шә',
+			'Ы',
+			'Ҩ',
+			'Џ',
+			'Џь',
+			'ь',
+			'ә',
+		], Language::factory( 'ab' ) );
+	}
+}
diff --git a/www/wiki/includes/collation/BashkirUppercaseCollation.php b/www/wiki/includes/collation/BashkirUppercaseCollation.php
new file mode 100644
index 00000000..33ed9bc8
--- /dev/null
+++ b/www/wiki/includes/collation/BashkirUppercaseCollation.php
@@ -0,0 +1,71 @@
+<?php
+/**
+ * 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
+ *
+ * @since 1.30
+ *
+ * @file
+ */
+
+class BashkirUppercaseCollation extends CustomUppercaseCollation {
+
+	public function __construct() {
+		parent::__construct( [
+			'А',
+			'Б',
+			'В',
+			'Г',
+			'Ғ',
+			'Д',
+			'Ҙ',
+			'Е',
+			'Ё',
+			'Ж',
+			'З',
+			'И',
+			'Й',
+			'К',
+			'Ҡ',
+			'Л',
+			'М',
+			'Н',
+			'Ң',
+			'О',
+			'Ө',
+			'П',
+			'Р',
+			'С',
+			'Ҫ',
+			'Т',
+			'У',
+			'Ү',
+			'Ф',
+			'Х',
+			'Һ',
+			'Ц',
+			'Ч',
+			'Ш',
+			'Щ',
+			'Ъ',
+			'Ы',
+			'Ь',
+			'Э',
+			'Ә',
+			'Ю',
+			'Я',
+		], Language::factory( 'ba' ) );
+	}
+}
diff --git a/www/wiki/includes/collation/Collation.php b/www/wiki/includes/collation/Collation.php
new file mode 100644
index 00000000..30cae5a8
--- /dev/null
+++ b/www/wiki/includes/collation/Collation.php
@@ -0,0 +1,135 @@
+<?php
+/**
+ * Database row sorting.
+ *
+ * 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
+ */
+
+/**
+ * @since 1.16.3
+ * @author Tim Starling
+ */
+abstract class Collation {
+	private static $instance;
+
+	/**
+	 * @since 1.16.3
+	 * @return Collation
+	 */
+	public static function singleton() {
+		if ( !self::$instance ) {
+			global $wgCategoryCollation;
+			self::$instance = self::factory( $wgCategoryCollation );
+		}
+		return self::$instance;
+	}
+
+	/**
+	 * @since 1.16.3
+	 * @throws MWException
+	 * @param string $collationName
+	 * @return Collation
+	 */
+	public static function factory( $collationName ) {
+		global $wgContLang;
+
+		switch ( $collationName ) {
+			case 'uppercase':
+				return new UppercaseCollation;
+			case 'numeric':
+				return new NumericUppercaseCollation( $wgContLang );
+			case 'identity':
+				return new IdentityCollation;
+			case 'uca-default':
+				return new IcuCollation( 'root' );
+			case 'uca-default-u-kn':
+				return new IcuCollation( 'root-u-kn' );
+			case 'xx-uca-ckb':
+				return new CollationCkb;
+			case 'xx-uca-et':
+				return new CollationEt;
+			case 'xx-uca-fa':
+				return new CollationFa;
+			case 'uppercase-ab':
+				return new AbkhazUppercaseCollation;
+			case 'uppercase-ba':
+				return new BashkirUppercaseCollation;
+			case 'uppercase-se':
+				return new NorthernSamiUppercaseCollation;
+			default:
+				$match = [];
+				if ( preg_match( '/^uca-([A-Za-z@=-]+)$/', $collationName, $match ) ) {
+					return new IcuCollation( $match[1] );
+				}
+
+				# Provide a mechanism for extensions to hook in.
+				$collationObject = null;
+				Hooks::run( 'Collation::factory', [ $collationName, &$collationObject ] );
+
+				if ( $collationObject instanceof Collation ) {
+					return $collationObject;
+				}
+
+				// If all else fails...
+				throw new MWException( __METHOD__ . ": unknown collation type \"$collationName\"" );
+		}
+	}
+
+	/**
+	 * Given a string, convert it to a (hopefully short) key that can be used
+	 * for efficient sorting.  A binary sort according to the sortkeys
+	 * corresponds to a logical sort of the corresponding strings.  Current
+	 * code expects that a line feed character should sort before all others, but
+	 * has no other particular expectations (and that one can be changed if
+	 * necessary).
+	 *
+	 * @since 1.16.3
+	 *
+	 * @param string $string UTF-8 string
+	 * @return string Binary sortkey
+	 */
+	abstract function getSortKey( $string );
+
+	/**
+	 * Given a string, return the logical "first letter" to be used for
+	 * grouping on category pages and so on.  This has to be coordinated
+	 * carefully with convertToSortkey(), or else the sorted list might jump
+	 * back and forth between the same "initial letters" or other pathological
+	 * behavior.  For instance, if you just return the first character, but "a"
+	 * sorts the same as "A" based on getSortKey(), then you might get a
+	 * list like
+	 *
+	 * == A ==
+	 * * [[Aardvark]]
+	 *
+	 * == a ==
+	 * * [[antelope]]
+	 *
+	 * == A ==
+	 * * [[Ape]]
+	 *
+	 * etc., assuming for the sake of argument that $wgCapitalLinks is false.
+	 *
+	 * @since 1.16.3
+	 *
+	 * @param string $string UTF-8 string
+	 * @return string UTF-8 string corresponding to the first letter of input
+	 */
+	abstract function getFirstLetter( $string );
+
+}
diff --git a/www/wiki/includes/collation/CollationCkb.php b/www/wiki/includes/collation/CollationCkb.php
new file mode 100644
index 00000000..01a4f7f5
--- /dev/null
+++ b/www/wiki/includes/collation/CollationCkb.php
@@ -0,0 +1,35 @@
+<?php
+/**
+ * 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
+ */
+
+/**
+ * Workaround for the lack of support of Sorani Kurdish / Central Kurdish language ('ckb') in ICU.
+ *
+ * Uses the same collation rules as Persian / Farsi ('fa'), but different characters for digits.
+ *
+ * @since 1.23
+ */
+class CollationCkb extends IcuCollation {
+	public function __construct() {
+		// This will set $locale and collators, which affect the actual sorting order
+		parent::__construct( 'fa' );
+		// Override the 'fa' language set by parent constructor, which affects #getFirstLetterData()
+		$this->digitTransformLanguage = Language::factory( 'ckb' );
+	}
+}
diff --git a/www/wiki/includes/collation/CollationEt.php b/www/wiki/includes/collation/CollationEt.php
new file mode 100644
index 00000000..ca7b7653
--- /dev/null
+++ b/www/wiki/includes/collation/CollationEt.php
@@ -0,0 +1,60 @@
+<?php
+/**
+ * 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
+ */
+
+/**
+ * Workaround for incorrect collation of Estonian language ('et') in ICU (T56168).
+ *
+ * 'W' and 'V' should not be considered the same letter for the purposes of collation in modern
+ * Estonian. We work around this by replacing 'W' and 'w' with 'ᴡ' U+1D21 'LATIN LETTER SMALL
+ * CAPITAL W' for sortkey generation, which is collated like 'W' and is not tailored to have the
+ * same primary weight as 'V' in Estonian.
+ *
+ * @since 1.24
+ */
+class CollationEt extends IcuCollation {
+	public function __construct() {
+		parent::__construct( 'et' );
+	}
+
+	private static function mangle( $string ) {
+		return str_replace(
+			[ 'w', 'W' ],
+			'ᴡ', // U+1D21 'LATIN LETTER SMALL CAPITAL W'
+			$string
+		);
+	}
+
+	private static function unmangle( $string ) {
+		// Casing data is lost…
+		return str_replace(
+			'ᴡ', // U+1D21 'LATIN LETTER SMALL CAPITAL W'
+			'W',
+			$string
+		);
+	}
+
+	public function getSortKey( $string ) {
+		return parent::getSortKey( self::mangle( $string ) );
+	}
+
+	public function getFirstLetter( $string ) {
+		return self::unmangle( parent::getFirstLetter( self::mangle( $string ) ) );
+	}
+}
diff --git a/www/wiki/includes/collation/CollationFa.php b/www/wiki/includes/collation/CollationFa.php
new file mode 100644
index 00000000..7410886e
--- /dev/null
+++ b/www/wiki/includes/collation/CollationFa.php
@@ -0,0 +1,60 @@
+<?php
+/**
+ * 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
+ */
+
+/**
+ * Temporary workaround for incorrect collation of Persian language ('fa') in ICU 52 (bug T139110).
+ *
+ * Replace with other letters that appear in an okish spot in the alphabet
+ *
+ *  - Characters 'و' 'ا' (often appear at the beginning of words)
+ *  - Characters 'ٲ' 'ٳ' (may appear at the beginning of words in loanwords)
+ *
+ * @since 1.29
+ */
+class CollationFa extends IcuCollation {
+
+	// Really hacky - replace with stuff from other blocks.
+	private $override = [
+		// U+0627 ARABIC LETTER ALEF => U+0623 ARABIC LETTER ALEF WITH HAMZA ABOVE
+		"\xd8\xa7" => "\xd8\xa3",
+		// U+0648 ARABIC LETTER WAW => U+0649 ARABIC LETTER ALEF MAKSURA
+		"\xd9\x88" => "\xd9\x89",
+		// U+0672 ARABIC LETTER ALEF WITH WAVY HAMZA ABOVE => U+F3001 (private use area)
+		"\xd9\xb2" => "\xF3\xB3\x80\x81",
+		// U+0673 ARABIC LETTER ALEF WITH WAVY HAMZA BELOW => U+F3002 (private use area)
+		"\xd9\xb3" => "\xF3\xB3\x80\x82",
+	];
+
+	public function __construct() {
+		parent::__construct( 'fa' );
+	}
+
+	public function getSortKey( $string ) {
+		$modified = strtr( $string, $this->override );
+		return parent::getSortKey( $modified );
+	}
+
+	public function getFirstLetter( $string ) {
+		if ( isset( $this->override[substr( $string, 0, 2 )] ) ) {
+			return substr( $string, 0, 2 );
+		}
+		return parent::getFirstLetter( $string );
+	}
+}
diff --git a/www/wiki/includes/collation/CustomUppercaseCollation.php b/www/wiki/includes/collation/CustomUppercaseCollation.php
new file mode 100644
index 00000000..170d5c2c
--- /dev/null
+++ b/www/wiki/includes/collation/CustomUppercaseCollation.php
@@ -0,0 +1,98 @@
+<?php
+/**
+ * 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
+ *
+ * @since 1.30
+ *
+ * @file
+ */
+
+/**
+ * Resort normal UTF-8 order by putting a bunch of stuff in PUA
+ *
+ * This takes a bunch of characters (The alphabet) that should,
+ * be together, and converts them all to private-use-area characters
+ * so that they are all sorted in the right order relative to each
+ * other.
+ *
+ * This renumbers characters starting at U+F3000 (Chosen to avoid
+ * conflicts with other people using private use area)
+ *
+ * This does not support fancy things like secondary differences, etc.
+ * (It supports digraphs, trigraphs etc. though.)
+ *
+ * It is expected most people will subclass this and just override the
+ * constructor to hard-code an alphabet.
+ */
+class CustomUppercaseCollation extends NumericUppercaseCollation {
+
+	/** @var array $alphabet Sorted array of letters */
+	private $alphabet;
+
+	/** @var array $puaSubset List of private use area codes */
+	private $puaSubset;
+
+	/**
+	 * @note This assumes $alphabet does not contain U+F3000-U+F3FFF
+	 *
+	 * @param array $alphabet Sorted array of uppercase characters.
+	 * @param Language $lang What language for number sorting.
+	 */
+	public function __construct( array $alphabet, Language $lang ) {
+		if ( count( $alphabet ) < 1 || count( $alphabet ) >= 4096 ) {
+			throw new UnexpectedValueException( "Alphabet must be < 4096 items" );
+		}
+		$this->firstLetters = $alphabet;
+		// For digraphs, only the first letter is capitalized in input
+		$this->alphabet = array_map( [ $lang, 'uc' ], $alphabet );
+
+		$this->puaSubset = [];
+		$len = count( $alphabet );
+		for ( $i = 0; $i < $len; $i++ ) {
+			$this->puaSubset[] = "\xF3\xB3" . chr( floor( $i / 64 ) + 128 ) . chr( ( $i % 64 ) + 128 );
+		}
+
+		// Sort these arrays so that any trigraphs, digraphs etc. are first
+		// (and they get replaced first in convertToPua()).
+		$lengths = array_map( 'mb_strlen', $this->alphabet );
+		array_multisort( $lengths, SORT_DESC, $this->firstLetters, $this->alphabet, $this->puaSubset );
+
+		parent::__construct( $lang );
+	}
+
+	private function convertToPua( $string ) {
+		return str_replace( $this->alphabet, $this->puaSubset, $string );
+	}
+
+	public function getSortKey( $string ) {
+		return $this->convertToPua( parent::getSortKey( $string ) );
+	}
+
+	public function getFirstLetter( $string ) {
+		$sortkey = $this->getSortKey( $string );
+
+		// In case a title begins with a character from our alphabet, return the corresponding
+		// first-letter. (This also happens if the title has a corresponding PUA code in it, to avoid
+		// inconsistent behaviour. This class mostly assumes that people will not use PUA codes.)
+		$index = array_search( substr( $sortkey, 0, 4 ), $this->puaSubset );
+		if ( $index !== false ) {
+			return $this->firstLetters[ $index ];
+		}
+
+		// String begins with a character outside of our alphabet, fall back
+		return parent::getFirstLetter( $string );
+	}
+}
diff --git a/www/wiki/includes/collation/IcuCollation.php b/www/wiki/includes/collation/IcuCollation.php
new file mode 100644
index 00000000..9ac81ae0
--- /dev/null
+++ b/www/wiki/includes/collation/IcuCollation.php
@@ -0,0 +1,588 @@
+<?php
+/**
+ * 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
+ */
+
+/**
+ * @since 1.16.3
+ */
+class IcuCollation extends Collation {
+	const FIRST_LETTER_VERSION = 3;
+
+	/** @var Collator */
+	private $primaryCollator;
+
+	/** @var Collator */
+	private $mainCollator;
+
+	/** @var string */
+	private $locale;
+
+	/** @var Language */
+	protected $digitTransformLanguage;
+
+	/** @var bool */
+	private $useNumericCollation = false;
+
+	/** @var array */
+	private $firstLetterData;
+
+	/**
+	 * Unified CJK blocks.
+	 *
+	 * The same definition of a CJK block must be used for both Collation and
+	 * generateCollationData.php. These blocks are omitted from the first
+	 * letter data, as an optimisation measure and because the default UCA table
+	 * is pretty useless for sorting Chinese text anyway. Japanese and Korean
+	 * blocks are not included here, because they are smaller and more useful.
+	 */
+	private static $cjkBlocks = [
+		[ 0x2E80, 0x2EFF ], // CJK Radicals Supplement
+		[ 0x2F00, 0x2FDF ], // Kangxi Radicals
+		[ 0x2FF0, 0x2FFF ], // Ideographic Description Characters
+		[ 0x3000, 0x303F ], // CJK Symbols and Punctuation
+		[ 0x31C0, 0x31EF ], // CJK Strokes
+		[ 0x3200, 0x32FF ], // Enclosed CJK Letters and Months
+		[ 0x3300, 0x33FF ], // CJK Compatibility
+		[ 0x3400, 0x4DBF ], // CJK Unified Ideographs Extension A
+		[ 0x4E00, 0x9FFF ], // CJK Unified Ideographs
+		[ 0xF900, 0xFAFF ], // CJK Compatibility Ideographs
+		[ 0xFE30, 0xFE4F ], // CJK Compatibility Forms
+		[ 0x20000, 0x2A6DF ], // CJK Unified Ideographs Extension B
+		[ 0x2A700, 0x2B73F ], // CJK Unified Ideographs Extension C
+		[ 0x2B740, 0x2B81F ], // CJK Unified Ideographs Extension D
+		[ 0x2F800, 0x2FA1F ], // CJK Compatibility Ideographs Supplement
+	];
+
+	/**
+	 * Additional characters (or character groups) to be considered separate
+	 * letters for given languages, or to be removed from the list of such
+	 * letters (denoted by keys starting with '-').
+	 *
+	 * These are additions to (or subtractions from) the data stored in the
+	 * first-letters-root.ser file (which among others includes full basic latin,
+	 * cyrillic and greek alphabets).
+	 *
+	 * "Separate letter" is a letter that would have a separate heading/section
+	 * for it in a dictionary or a phone book in this language. This data isn't
+	 * used for sorting (the ICU library handles that), only for deciding which
+	 * characters (or character groups) to use as headings.
+	 *
+	 * Initially generated based on the primary level of Unicode collation
+	 * tailorings available at http://developer.mimer.com/charts/tailorings.htm ,
+	 * later modified.
+	 *
+	 * Empty arrays are intended; this signifies that the data for the language is
+	 * available and that there are, in fact, no additional letters to consider.
+	 */
+	private static $tailoringFirstLetters = [
+		'af' => [],
+		'am' => [],
+		'ar' => [],
+		'as' => [ "\xe0\xa6\x82", "\xe0\xa6\x81", "\xe0\xa6\x83", "\xe0\xa7\x8e", "ক্ষ " ],
+		'ast' => [ "Ch", "Ll", "Ñ" ], // not in libicu
+		'az' => [ "Ç", "Ə", "Ğ", "İ", "Ö", "Ş", "Ü" ],
+		'be' => [ "Ё" ],
+		'be-tarask' => [ "Ё" ],
+		'bg' => [],
+		'bn' => [ 'ং', 'ঃ', 'ঁ' ],
+		'bn@collation=traditional' => [
+			'ং', 'ঃ', 'ঁ', 'ক্', 'খ্', 'গ্', 'ঘ্', 'ঙ্', 'চ্', 'ছ্', 'জ্', 'ঝ্',
+			'ঞ্', 'ট্', 'ঠ্', 'ড্', 'ঢ্', 'ণ্', 'ৎ', 'থ্', 'দ্', 'ধ্', 'ন্', 'প্',
+			'ফ্', 'ব্', 'ভ্', 'ম্', 'য্', 'র্', 'ৰ্', 'ল্', 'ৱ্', 'শ্', 'ষ্', 'স্', 'হ্'
+		],
+		'bo' => [],
+		'br' => [ "Ch", "C'h" ],
+		'bs' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
+		'bs-Cyrl' => [],
+		'ca' => [],
+		'chr' => [],
+		'co' => [], // not in libicu
+		'cs' => [ "Č", "Ch", "Ř", "Š", "Ž" ],
+		'cy' => [ "Ch", "Dd", "Ff", "Ng", "Ll", "Ph", "Rh", "Th" ],
+		'da' => [ "Æ", "Ø", "Å" ],
+		'de' => [],
+		'de-AT@collation=phonebook' => [ 'ä', 'ö', 'ü', 'ß' ],
+		'dsb' => [ "Č", "Ć", "Dź", "Ě", "Ch", "Ł", "Ń", "Ŕ", "Š", "Ś", "Ž", "Ź" ],
+		'ee' => [ "Dz", "Ɖ", "Ɛ", "Ƒ", "Gb", "Ɣ", "Kp", "Ny", "Ŋ", "Ɔ", "Ts", "Ʋ" ],
+		'el' => [],
+		'en' => [],
+		'eo' => [ "Ĉ", "Ĝ", "Ĥ", "Ĵ", "Ŝ", "Ŭ" ],
+		'es' => [ "Ñ" ],
+		'et' => [ "Š", "Ž", "Õ", "Ä", "Ö", "Ü", "W" ], // added W for CollationEt (xx-uca-et)
+		'eu' => [ "Ñ" ], // not in libicu
+		'fa' => [
+			// RTL, let's put each letter on a new line
+			"آ",
+			"ء",
+			"ه",
+			"ا",
+			"و"
+		],
+		'fi' => [ "Å", "Ä", "Ö" ],
+		'fil' => [ "Ñ", "Ng" ],
+		'fo' => [ "Á", "Ð", "Í", "Ó", "Ú", "Ý", "Æ", "Ø", "Å" ],
+		'fr' => [],
+		'fr-CA' => [], // fr-CA sorts accents slightly different from fr.
+		'fur' => [ "À", "Á", "Â", "È", "Ì", "Ò", "Ù" ], // not in libicu
+		'fy' => [], // not in libicu
+		'ga' => [],
+		'gd' => [], // not in libicu
+		'gl' => [ "Ch", "Ll", "Ñ" ],
+		'gu' => [ "\xe0\xaa\x82", "\xe0\xaa\x83", "\xe0\xaa\x81", "\xe0\xaa\xb3" ],
+		'ha' => [ 'Ɓ', 'Ɗ', 'Ƙ', 'Sh', 'Ts', 'Ƴ' ],
+		'haw' => [ 'ʻ' ],
+		'he' => [],
+		'hi' => [ "\xe0\xa4\x82", "\xe0\xa4\x83" ],
+		'hr' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
+		'hsb' => [ "Č", "Dź", "Ě", "Ch", "Ł", "Ń", "Ř", "Š", "Ć", "Ž" ],
+		'hu' => [ "Cs", "Dz", "Dzs", "Gy", "Ly", "Ny", "Ö", "Sz", "Ty", "Ü", "Zs" ],
+		'hy' => [ "և" ],
+		'id' => [],
+		'ig' => [ "Ch", "Gb", "Gh", "Gw", "Ị", "Kp", "Kw", "Ṅ", "Nw", "Ny", "Ọ", "Sh", "Ụ" ],
+		'is' => [ "Á", "Ð", "É", "Í", "Ó", "Ú", "Ý", "Þ", "Æ", "Ö", "Å" ],
+		'it' => [],
+		'ka' => [],
+		'kk' => [ "Ү", "І" ],
+		'kl' => [ "Æ", "Ø", "Å" ],
+		'km' => [
+			"រ", "ឫ", "ឬ", "ល", "ឭ", "ឮ", "\xe1\x9e\xbb\xe1\x9f\x86",
+			"\xe1\x9f\x86", "\xe1\x9e\xb6\xe1\x9f\x86", "\xe1\x9f\x87",
+			"\xe1\x9e\xb7\xe1\x9f\x87", "\xe1\x9e\xbb\xe1\x9f\x87",
+			"\xe1\x9f\x81\xe1\x9f\x87", "\xe1\x9f\x84\xe1\x9f\x87",
+		],
+		'kn' => [ "\xe0\xb2\x81", "\xe0\xb2\x83", "\xe0\xb3\xb1", "\xe0\xb3\xb2" ],
+		'kok' => [ "\xe0\xa4\x82", "\xe0\xa4\x83", "ळ", "क्ष" ],
+		'ku' => [ "Ç", "Ê", "Î", "Ş", "Û" ], // not in libicu
+		'ky' => [ "Ё" ],
+		'la' => [], // not in libicu
+		'lb' => [],
+		'lkt' => [ 'Č', 'Ǧ', 'Ȟ', 'Š', 'Ž' ],
+		'ln' => [ 'Ɛ' ],
+		'lo' => [],
+		'lt' => [ "Č", "Š", "Ž" ],
+		'lv' => [ "Č", "Ģ", "Ķ", "Ļ", "Ņ", "Š", "Ž" ],
+		'mk' => [ "Ѓ", "Ќ" ],
+		'ml' => [],
+		'mn' => [],
+		'mo' => [ "Ă", "Â", "Î", "Ș", "Ț" ], // not in libicu
+		'mr' => [ "\xe0\xa4\x82", "\xe0\xa4\x83", "ळ", "क्ष", "ज्ञ" ],
+		'ms' => [],
+		'mt' => [ "Ċ", "Ġ", "Għ", "Ħ", "Ż" ],
+		'nb' => [ "Æ", "Ø", "Å" ],
+		'ne' => [],
+		'nl' => [],
+		'nn' => [ "Æ", "Ø", "Å" ],
+		'no' => [ "Æ", "Ø", "Å" ], // not in libicu. You should probably use nb or nn instead.
+		'oc' => [], // not in libicu
+		'om' => [ 'Ch', 'Dh', 'Kh', 'Ny', 'Ph', 'Sh' ],
+		'or' => [ "\xe0\xac\x81", "\xe0\xac\x82", "\xe0\xac\x83", "କ୍ଷ" ],
+		'pa' => [ "\xe0\xa9\x8d" ],
+		'pl' => [ "Ą", "Ć", "Ę", "Ł", "Ń", "Ó", "Ś", "Ź", "Ż" ],
+		'pt' => [],
+		'rm' => [], // not in libicu
+		'ro' => [ "Ă", "Â", "Î", "Ș", "Ț" ],
+		'ru' => [],
+		'rup' => [ "Ă", "Â", "Î", "Ľ", "Ń", "Ș", "Ț" ], // not in libicu
+		'sco' => [],
+		'se' => [
+			'Á', 'Č', 'Ʒ', 'Ǯ', 'Đ', 'Ǧ', 'Ǥ', 'Ǩ', 'Ŋ',
+			'Š', 'Ŧ', 'Ž', 'Ø', 'Æ', 'Ȧ', 'Ä', 'Ö'
+		],
+		'si' => [ "\xe0\xb6\x82", "\xe0\xb6\x83", "\xe0\xb6\xa4" ],
+		'sk' => [ "Ä", "Č", "Ch", "Ô", "Š", "Ž" ],
+		'sl' => [ "Č", "Š", "Ž" ],
+		'smn' => [ "Á", "Č", "Đ", "Ŋ", "Š", "Ŧ", "Ž", "Æ", "Ø", "Å", "Ä", "Ö" ],
+		'sq' => [ "Ç", "Dh", "Ë", "Gj", "Ll", "Nj", "Rr", "Sh", "Th", "Xh", "Zh" ],
+		'sr' => [],
+		'sr-Latn' => [ "Č", "Ć", "Dž", "Đ", "Lj", "Nj", "Š", "Ž" ],
+		'sv' => [ "Å", "Ä", "Ö" ],
+		'sv@collation=standard' => [ "Å", "Ä", "Ö" ],
+		'sw' => [],
+		'ta' => [
+			"\xE0\xAE\x82", "ஃ", "க்ஷ", "க்", "ங்", "ச்", "ஞ்", "ட்", "ண்", "த்", "ந்",
+			"ப்", "ம்", "ய்", "ர்", "ல்", "வ்", "ழ்", "ள்", "ற்", "ன்", "ஜ்", "ஶ்", "ஷ்",
+			"ஸ்", "ஹ்", "க்ஷ்"
+		],
+		'te' => [ "\xe0\xb0\x81", "\xe0\xb0\x82", "\xe0\xb0\x83" ],
+		'th' => [ "ฯ", "\xe0\xb9\x86", "\xe0\xb9\x8d", "\xe0\xb8\xba" ],
+		'tk' => [ "Ç", "Ä", "Ž", "Ň", "Ö", "Ş", "Ü", "Ý" ],
+		'tl' => [ "Ñ", "Ng" ], // not in libicu
+		'to' => [ "Ng", "ʻ" ],
+		'tr' => [ "Ç", "Ğ", "İ", "Ö", "Ş", "Ü" ],
+		'tt' => [ "Ә", "Ө", "Ү", "Җ", "Ң", "Һ" ], // not in libicu
+		'uk' => [ "Ґ", "Ь" ],
+		'uz' => [ "Ch", "G'", "Ng", "O'", "Sh" ], // not in libicu
+		'vi' => [ "Ă", "Â", "Đ", "Ê", "Ô", "Ơ", "Ư" ],
+		'vo' => [ "Ä", "Ö", "Ü" ],
+		'yi' => [
+			"\xd7\x91\xd6\xbf", "\xd7\x9b\xd6\xbc", "\xd7\xa4\xd6\xbc",
+			"\xd7\xa9\xd7\x82", "\xd7\xaa\xd6\xbc"
+		],
+		'yo' => [ "Ẹ", "Gb", "Ọ", "Ṣ" ],
+		'zu' => [],
+	];
+
+	/**
+	 * @since 1.16.3
+	 */
+	const RECORD_LENGTH = 14;
+
+	public function __construct( $locale ) {
+		if ( !extension_loaded( 'intl' ) ) {
+			throw new MWException( 'An ICU collation was requested, ' .
+				'but the intl extension is not available.' );
+		}
+
+		$this->locale = $locale;
+		// Drop everything after the '@' in locale's name
+		$localeParts = explode( '@', $locale );
+		$this->digitTransformLanguage = Language::factory( $locale === 'root' ? 'en' : $localeParts[0] );
+
+		$this->mainCollator = Collator::create( $locale );
+		if ( !$this->mainCollator ) {
+			throw new MWException( "Invalid ICU locale specified for collation: $locale" );
+		}
+
+		$this->primaryCollator = Collator::create( $locale );
+		$this->primaryCollator->setStrength( Collator::PRIMARY );
+
+		// If the special suffix for numeric collation is present, turn on numeric collation.
+		if ( substr( $locale, -5, 5 ) === '-u-kn' ) {
+			$this->useNumericCollation = true;
+			// Strip off the special suffix so it doesn't trip up fetchFirstLetterData().
+			$this->locale = substr( $this->locale, 0, -5 );
+			$this->mainCollator->setAttribute( Collator::NUMERIC_COLLATION, Collator::ON );
+			$this->primaryCollator->setAttribute( Collator::NUMERIC_COLLATION, Collator::ON );
+		}
+	}
+
+	public function getSortKey( $string ) {
+		return $this->mainCollator->getSortKey( $string );
+	}
+
+	public function getPrimarySortKey( $string ) {
+		return $this->primaryCollator->getSortKey( $string );
+	}
+
+	public function getFirstLetter( $string ) {
+		$string = strval( $string );
+		if ( $string === '' ) {
+			return '';
+		}
+
+		$firstChar = mb_substr( $string, 0, 1, 'UTF-8' );
+
+		// If the first character is a CJK character, just return that character.
+		if ( ord( $firstChar ) > 0x7f && self::isCjk( UtfNormal\Utils::utf8ToCodepoint( $firstChar ) ) ) {
+			return $firstChar;
+		}
+
+		$sortKey = $this->getPrimarySortKey( $string );
+
+		// Do a binary search to find the correct letter to sort under
+		$min = ArrayUtils::findLowerBound(
+			[ $this, 'getSortKeyByLetterIndex' ],
+			$this->getFirstLetterCount(),
+			'strcmp',
+			$sortKey );
+
+		if ( $min === false ) {
+			// Before the first letter
+			return '';
+		}
+
+		$sortLetter = $this->getLetterByIndex( $min );
+
+		if ( $this->useNumericCollation ) {
+			// If the sort letter is a number, return '0–9' (or localized equivalent).
+			// ASCII value of 0 is 48. ASCII value of 9 is 57.
+			// Note that this also applies to non-Arabic numerals since they are
+			// mapped to Arabic numeral sort letters. For example, ২ sorts as 2.
+			if ( ord( $sortLetter ) >= 48 && ord( $sortLetter ) <= 57 ) {
+				$sortLetter = wfMessage( 'category-header-numerals' )->numParams( 0, 9 )->text();
+			}
+		}
+		return $sortLetter;
+	}
+
+	/**
+	 * @since 1.16.3
+	 * @return array
+	 */
+	public function getFirstLetterData() {
+		if ( $this->firstLetterData === null ) {
+			$cache = ObjectCache::getLocalServerInstance( CACHE_ANYTHING );
+			$cacheKey = $cache->makeKey(
+				'first-letters',
+				static::class,
+				$this->locale,
+				$this->digitTransformLanguage->getCode(),
+				self::getICUVersion(),
+				self::FIRST_LETTER_VERSION
+			);
+			$this->firstLetterData = $cache->getWithSetCallback( $cacheKey, $cache::TTL_WEEK, function () {
+				return $this->fetchFirstLetterData();
+			} );
+		}
+		return $this->firstLetterData;
+	}
+
+	/**
+	 * @return array
+	 * @throws MWException
+	 */
+	private function fetchFirstLetterData() {
+		// Generate data from serialized data file
+		if ( isset( self::$tailoringFirstLetters[$this->locale] ) ) {
+			$letters = wfGetPrecompiledData( 'first-letters-root.ser' );
+			// Append additional characters
+			$letters = array_merge( $letters, self::$tailoringFirstLetters[$this->locale] );
+			// Remove unnecessary ones, if any
+			if ( isset( self::$tailoringFirstLetters['-' . $this->locale] ) ) {
+				$letters = array_diff( $letters, self::$tailoringFirstLetters['-' . $this->locale] );
+			}
+			// Apply digit transforms
+			$digits = [ '0', '1', '2', '3', '4', '5', '6', '7', '8', '9' ];
+			$letters = array_diff( $letters, $digits );
+			foreach ( $digits as $digit ) {
+				$letters[] = $this->digitTransformLanguage->formatNum( $digit, true );
+			}
+		} else {
+			$letters = wfGetPrecompiledData( "first-letters-{$this->locale}.ser" );
+			if ( $letters === false ) {
+				throw new MWException( "MediaWiki does not support ICU locale " .
+					"\"{$this->locale}\"" );
+			}
+		}
+
+		/* Sort the letters.
+		 *
+		 * It's impossible to have the precompiled data file properly sorted,
+		 * because the sort order changes depending on ICU version. If the
+		 * array is not properly sorted, the binary search will return random
+		 * results.
+		 *
+		 * We also take this opportunity to remove primary collisions.
+		 */
+		$letterMap = [];
+		foreach ( $letters as $letter ) {
+			$key = $this->getPrimarySortKey( $letter );
+			if ( isset( $letterMap[$key] ) ) {
+				// Primary collision (two characters with the same sort position).
+				// Keep whichever one sorts first in the main collator.
+				$comp = $this->mainCollator->compare( $letter, $letterMap[$key] );
+				wfDebug( "Primary collision '$letter' '{$letterMap[$key]}' (comparison: $comp)\n" );
+				// If that also has a collision, use codepoint as a tiebreaker.
+				if ( $comp === 0 ) {
+					// TODO Use <=> operator when PHP 7 is allowed.
+					$comp = UtfNormal\Utils::utf8ToCodepoint( $letter ) -
+						UtfNormal\Utils::utf8ToCodepoint( $letterMap[$key] );
+				}
+				if ( $comp < 0 ) {
+					$letterMap[$key] = $letter;
+				}
+			} else {
+				$letterMap[$key] = $letter;
+			}
+		}
+		ksort( $letterMap, SORT_STRING );
+
+		/* Remove duplicate prefixes. Basically if something has a sortkey
+		 * which is a prefix of some other sortkey, then it is an
+		 * expansion and probably should not be considered a section
+		 * header.
+		 *
+		 * For example 'þ' is sometimes sorted as if it is the letters
+		 * 'th'. Other times it is its own primary element. Another
+		 * example is '₨'. Sometimes its a currency symbol. Sometimes it
+		 * is an 'R' followed by an 's'.
+		 *
+		 * Additionally an expanded element should always sort directly
+		 * after its first element due to they way sortkeys work.
+		 *
+		 * UCA sortkey elements are of variable length but no collation
+		 * element should be a prefix of some other element, so I think
+		 * this is safe. See:
+		 * - https://ssl.icu-project.org/repos/icu/icuhtml/trunk/design/collation/ICU_collation_design.htm
+		 * - http://site.icu-project.org/design/collation/uca-weight-allocation
+		 *
+		 * Additionally, there is something called primary compression to
+		 * worry about. Basically, if you have two primary elements that
+		 * are more than one byte and both start with the same byte then
+		 * the first byte is dropped on the second primary. Additionally
+		 * either \x03 or \xFF may be added to mean that the next primary
+		 * does not start with the first byte of the first primary.
+		 *
+		 * This shouldn't matter much, as the first primary is not
+		 * changed, and that is what we are comparing against.
+		 *
+		 * tl;dr: This makes some assumptions about how icu implements
+		 * collations. It seems incredibly unlikely these assumptions
+		 * will change, but nonetheless they are assumptions.
+		 */
+
+		$prev = false;
+		$duplicatePrefixes = [];
+		foreach ( $letterMap as $key => $value ) {
+			// Remove terminator byte. Otherwise the prefix
+			// comparison will get hung up on that.
+			$trimmedKey = rtrim( $key, "\0" );
+			if ( $prev === false || $prev === '' ) {
+				$prev = $trimmedKey;
+				// We don't yet have a collation element
+				// to compare against, so continue.
+				continue;
+			}
+
+			// Due to the fact the array is sorted, we only have
+			// to compare with the element directly previous
+			// to the current element (skipping expansions).
+			// An element "X" will always sort directly
+			// before "XZ" (Unless we have "XY", but we
+			// do not update $prev in that case).
+			if ( substr( $trimmedKey, 0, strlen( $prev ) ) === $prev ) {
+				$duplicatePrefixes[] = $key;
+				// If this is an expansion, we don't want to
+				// compare the next element to this element,
+				// but to what is currently $prev
+				continue;
+			}
+			$prev = $trimmedKey;
+		}
+		foreach ( $duplicatePrefixes as $badKey ) {
+			wfDebug( "Removing '{$letterMap[$badKey]}' from first letters.\n" );
+			unset( $letterMap[$badKey] );
+			// This code assumes that unsetting does not change sort order.
+		}
+		$data = [
+			'chars' => array_values( $letterMap ),
+			'keys' => array_keys( $letterMap ),
+		];
+
+		// Reduce memory usage before caching
+		unset( $letterMap );
+
+		return $data;
+	}
+
+	/**
+	 * @param string $index
+	 * @return string
+	 * @since 1.16.3
+	 */
+	public function getLetterByIndex( $index ) {
+		return $this->getFirstLetterData()['chars'][$index];
+	}
+
+	/**
+	 * @param string $index
+	 * @return string
+	 * @since 1.16.3
+	 */
+	public function getSortKeyByLetterIndex( $index ) {
+		return $this->getFirstLetterData()['keys'][$index];
+	}
+
+	/**
+	 * @return string
+	 * @since 1.16.3
+	 */
+	public function getFirstLetterCount() {
+		return count( $this->getFirstLetterData()['chars'] );
+	}
+
+	/**
+	 * Test if a code point is a CJK (Chinese, Japanese, Korean) character
+	 * @param int $codepoint
+	 * @return bool
+	 * @since 1.16.3
+	 */
+	public static function isCjk( $codepoint ) {
+		foreach ( self::$cjkBlocks as $block ) {
+			if ( $codepoint >= $block[0] && $codepoint <= $block[1] ) {
+				return true;
+			}
+		}
+		return false;
+	}
+
+	/**
+	 * Return the version of ICU library used by PHP's intl extension,
+	 * or false when the extension is not installed of the version
+	 * can't be determined.
+	 *
+	 * The constant INTL_ICU_VERSION this function refers to isn't really
+	 * documented. It is available since PHP 5.3.7 (see PHP 54561
+	 * https://bugs.php.net/bug.php?id=54561). This function will return
+	 * false on older PHPs.
+	 *
+	 * TODO: Remove the backwards-compatibility as MediaWiki now requires
+	 * higher levels of PHP.
+	 *
+	 * @since 1.21
+	 * @return string|bool
+	 */
+	static function getICUVersion() {
+		return defined( 'INTL_ICU_VERSION' ) ? INTL_ICU_VERSION : false;
+	}
+
+	/**
+	 * Return the version of Unicode appropriate for the version of ICU library
+	 * currently in use, or false when it can't be determined.
+	 *
+	 * @since 1.21
+	 * @return string|bool
+	 */
+	static function getUnicodeVersionForICU() {
+		$icuVersion = self::getICUVersion();
+		if ( !$icuVersion ) {
+			return false;
+		}
+
+		$versionPrefix = substr( $icuVersion, 0, 3 );
+		// Source: http://site.icu-project.org/download
+		$map = [
+			'59.' => '9.0',
+			'58.' => '9.0',
+			'57.' => '8.0',
+			'56.' => '8.0',
+			'55.' => '7.0',
+			'54.' => '7.0',
+			'53.' => '6.3',
+			'52.' => '6.3',
+			'51.' => '6.2',
+			'50.' => '6.2',
+			'49.' => '6.1',
+			'4.8' => '6.0',
+			'4.6' => '6.0',
+			'4.4' => '5.2',
+			'4.2' => '5.1',
+			'4.0' => '5.1',
+			'3.8' => '5.0',
+			'3.6' => '5.0',
+			'3.4' => '4.1',
+		];
+
+		if ( isset( $map[$versionPrefix] ) ) {
+			return $map[$versionPrefix];
+		} else {
+			return false;
+		}
+	}
+}
diff --git a/www/wiki/includes/collation/IdentityCollation.php b/www/wiki/includes/collation/IdentityCollation.php
new file mode 100644
index 00000000..46e7f38f
--- /dev/null
+++ b/www/wiki/includes/collation/IdentityCollation.php
@@ -0,0 +1,44 @@
+<?php
+/**
+ * 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
+ */
+
+/**
+ * Collation class that's essentially a no-op.
+ *
+ * Does sorting based on binary value of the string.
+ * Like how things were pre 1.17.
+ *
+ * @since 1.18
+ */
+class IdentityCollation extends Collation {
+
+	public function getSortKey( $string ) {
+		return $string;
+	}
+
+	public function getFirstLetter( $string ) {
+		global $wgContLang;
+		// Copied from UppercaseCollation.
+		// I'm kind of unclear on when this could happen...
+		if ( $string[0] == "\0" ) {
+			$string = substr( $string, 1 );
+		}
+		return $wgContLang->firstChar( $string );
+	}
+}
diff --git a/www/wiki/includes/collation/NorthernSamiUppercaseCollation.php b/www/wiki/includes/collation/NorthernSamiUppercaseCollation.php
new file mode 100644
index 00000000..d373749e
--- /dev/null
+++ b/www/wiki/includes/collation/NorthernSamiUppercaseCollation.php
@@ -0,0 +1,83 @@
+<?php
+/**
+ * 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
+ *
+ * @since 1.31
+ *
+ * @file
+ */
+
+/**
+ * Temporary workaround for incorrect collation of Northern Sami
+ * language ('se') in Wikimedia servers (see bug T181503).
+ *
+ * When the ICU's 'se' collation has been included in PHP-intl and Wikimedia
+ * servers updated to that new version of PHP, this file should be deleted
+ * and the collation for 'se' set to 'uca-se'.
+ *
+ * @since 1.31
+ */
+
+class NorthernSamiUppercaseCollation extends CustomUppercaseCollation {
+
+	public function __construct() {
+		parent::__construct( [
+			'A',
+			'Á',
+			'B',
+			'C',
+			'Č',
+			'Ʒ', // Not part of modern alphabet, but part of ICU
+			'Ǯ', // Not part of modern alphabet, but part of ICU
+			'D',
+			'Đ',
+			'E',
+			'F',
+			'G',
+			'Ǧ', // Not part of modern alphabet, but part of ICU
+			'Ǥ', // Not part of modern alphabet, but part of ICU
+			'H',
+			'I',
+			'J',
+			'K',
+			'Ǩ', // Not part of modern alphabet, but part of ICU
+			'L',
+			'M',
+			'N',
+			'Ŋ',
+			'O',
+			'P',
+			'Q',
+			'R',
+			'S',
+			'Š',
+			'T',
+			'Ŧ',
+			'U',
+			'V',
+			'W',
+			'X',
+			'Y',
+			'Z',
+			'Ž',
+			'Ø', // Not part of native alphabet, but part of ICU
+			'Æ', // Not part of native alphabet, but part of ICU
+			'Å', // Not part of native alphabet, but part of ICU
+			'Ä', // Not part of native alphabet, but part of ICU
+			'Ö', // Not part of native alphabet, but part of ICU
+		], Language::factory( 'se' ) );
+	}
+}
diff --git a/www/wiki/includes/collation/NumericUppercaseCollation.php b/www/wiki/includes/collation/NumericUppercaseCollation.php
new file mode 100644
index 00000000..4a2d776f
--- /dev/null
+++ b/www/wiki/includes/collation/NumericUppercaseCollation.php
@@ -0,0 +1,105 @@
+<?php
+/**
+ * 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
+ */
+
+/**
+ * Collation that orders text with numbers "naturally", so that 'Foo 1' < 'Foo 2' < 'Foo 12'.
+ *
+ * Note that this only works in terms of sequences of digits, and the behavior for decimal fractions
+ * or pretty-formatted numbers may be unexpected.
+ *
+ * Digits will be based on the wiki's content language settings. If
+ * you change the content language of a wiki you will need to run
+ * updateCollation.php --force. Only English (ASCII 0-9) and the
+ * localized version will be counted. Localized digits from other languages
+ * or weird unicode digit equivalents (e.g. ４, 𝟜, ⓸ , ⁴, etc) will not count.
+ *
+ * @since 1.28
+ */
+class NumericUppercaseCollation extends UppercaseCollation {
+
+	/**
+	 * @var $digitTransformLang Language How to convert digits (usually $wgContLang)
+	 */
+	private $digitTransformLang;
+
+	/**
+	 * @param Language $lang How to convert digits.
+	 *  For example, if given language "my" than ၇ is treated like 7.
+	 *
+	 * It is expected that usually this is given $wgContLang.
+	 */
+	public function __construct( Language $lang ) {
+		$this->digitTransformLang = $lang;
+		parent::__construct();
+	}
+
+	public function getSortKey( $string ) {
+		$sortkey = parent::getSortKey( $string );
+		$sortkey = $this->convertDigits( $sortkey );
+		// For each sequence of digits, insert the digit '0' and then the length of the sequence
+		// (encoded in two bytes) before it. That's all folks, it sorts correctly now! The '0' ensures
+		// correct position (where digits would normally sort), then the length will be compared putting
+		// shorter numbers before longer ones; if identical, then the characters will be compared, which
+		// generates the correct results for numbers of equal length.
+		$sortkey = preg_replace_callback( '/\d+/', function ( $matches ) {
+			// Strip any leading zeros
+			$number = ltrim( $matches[0], '0' );
+			$len = strlen( $number );
+			// This allows sequences of up to 65536 numeric characters to be handled correctly. One byte
+			// would allow only for 256, which doesn't feel future-proof.
+			$prefix = chr( floor( $len / 256 ) ) . chr( $len % 256 );
+			return '0' . $prefix . $number;
+		}, $sortkey );
+
+		return $sortkey;
+	}
+
+	/**
+	 * Convert localized digits to english digits.
+	 *
+	 * based on Language::parseFormattedNumber but without commas.
+	 *
+	 * @param string $string sortkey to unlocalize digits of
+	 * @return string Sortkey with all localized digits replaced with ASCII digits.
+	 */
+	private function convertDigits( $string ) {
+		$table = $this->digitTransformLang->digitTransformTable();
+		if ( $table ) {
+			$table = array_filter( $table );
+			$flipped = array_flip( $table );
+			// Some languages seem to also have commas in this table.
+			$flipped = array_filter( $flipped, 'is_numeric' );
+			$string = strtr( $string, $flipped );
+		}
+		return $string;
+	}
+
+	public function getFirstLetter( $string ) {
+		$convertedString = $this->convertDigits( $string );
+
+		if ( preg_match( '/^\d/', $convertedString ) ) {
+			return wfMessage( 'category-header-numerals' )
+				->numParams( 0, 9 )
+				->text();
+		} else {
+			return parent::getFirstLetter( $string );
+		}
+	}
+}
diff --git a/www/wiki/includes/collation/UppercaseCollation.php b/www/wiki/includes/collation/UppercaseCollation.php
new file mode 100644
index 00000000..92a4c3b4
--- /dev/null
+++ b/www/wiki/includes/collation/UppercaseCollation.php
@@ -0,0 +1,44 @@
+<?php
+/**
+ * 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
+ *
+ * @since 1.16.3
+ *
+ * @file
+ */
+
+class UppercaseCollation extends Collation {
+
+	private $lang;
+
+	public function __construct() {
+		// Get a language object so that we can use the generic UTF-8 uppercase
+		// function there
+		$this->lang = Language::factory( 'en' );
+	}
+
+	public function getSortKey( $string ) {
+		return $this->lang->uc( $string );
+	}
+
+	public function getFirstLetter( $string ) {
+		if ( $string[0] == "\0" ) {
+			$string = substr( $string, 1 );
+		}
+		return $this->lang->ucfirst( $this->lang->firstChar( $string ) );
+	}
+
+}