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diff --git a/www/wiki/includes/collation/CustomUppercaseCollation.php b/www/wiki/includes/collation/CustomUppercaseCollation.php
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+<?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 );
+	}
+}