1 files changed, 59 insertions, 14 deletions

diff --git a/includes/StringUtils.php b/includes/StringUtils.php
index 43275a66..f4c98f1d 100644
--- a/includes/StringUtils.php
+++ b/includes/StringUtils.php
@@ -24,6 +24,51 @@
  * A collection of static methods to play with strings.
  */
 class StringUtils {
+
+	/**
+	 * Test whether a string is valid UTF-8.
+	 *
+	 * The function check for invalid byte sequences, overlong encoding but
+	 * not for different normalisations.
+	 *
+	 * This relies internally on the mbstring function mb_check_encoding()
+	 * hardcoded to check against UTF-8. Whenever the function is not available
+	 * we fallback to a pure PHP implementation. Setting $disableMbstring to
+	 * true will skip the use of mb_check_encoding, this is mostly intended for
+	 * unit testing our internal implementation.
+	 *
+	 * @since 1.21
+	 *
+	 * @param string $value String to check
+	 * @param boolean $disableMbstring Whether to use the pure PHP
+	 * implementation instead of trying mb_check_encoding. Intended for unit
+	 * testing. Default: false
+	 *
+	 * @return boolean Whether the given $value is a valid UTF-8 encoded string
+	 */
+	static function isUtf8( $value, $disableMbstring = false ) {
+
+		if ( preg_match( '/[\x80-\xff]/', $value ) === 0 ) {
+			# no high bit set, this is pure ASCII which is de facto
+			# valid UTF-8
+			return true;
+		}
+
+		if ( !$disableMbstring && function_exists( 'mb_check_encoding' ) ) {
+			return mb_check_encoding( $value, 'UTF-8' );
+		} else {
+			$hasUtf8 = preg_match( '/^(?>
+				  [\x00-\x7f]
+				| [\xc0-\xdf][\x80-\xbf]
+				| [\xe0-\xef][\x80-\xbf]{2}
+				| [\xf0-\xf7][\x80-\xbf]{3}
+				| [\xf8-\xfb][\x80-\xbf]{4}
+				| \xfc[\x84-\xbf][\x80-\xbf]{4}
+			)+$/x', $value );
+			return ($hasUtf8 > 0 );
+		}
+	}
+
 	/**
 	 * Perform an operation equivalent to
 	 *
@@ -65,16 +110,16 @@ class StringUtils {
 	 * memory. The delimiters are literal strings, not regular expressions.
 	 *
 	 * If the start delimiter ends with an initial substring of the end delimiter,
-	 * e.g. in the case of C-style comments, the behaviour differs from the model
+	 * e.g. in the case of C-style comments, the behavior differs from the model
 	 * regex. In this implementation, the end must share no characters with the
 	 * start, so e.g. /*\/ is not considered to be both the start and end of a
 	 * comment. /*\/xy/*\/ is considered to be a single comment with contents /xy/.
 	 *
-	 * @param $startDelim String: start delimiter
-	 * @param $endDelim String: end delimiter
+	 * @param string $startDelim start delimiter
+	 * @param string $endDelim end delimiter
 	 * @param $callback Callback: function to call on each match
 	 * @param $subject String
-	 * @param $flags String: regular expression flags
+	 * @param string $flags regular expression flags
 	 * @throws MWException
 	 * @return string
 	 */
@@ -90,12 +135,12 @@ class StringUtils {
 		$m = array();
 
 		while ( $inputPos < strlen( $subject ) &&
-		  preg_match( "!($encStart)|($encEnd)!S$flags", $subject, $m, PREG_OFFSET_CAPTURE, $inputPos ) )
+			preg_match( "!($encStart)|($encEnd)!S$flags", $subject, $m, PREG_OFFSET_CAPTURE, $inputPos ) )
 		{
 			$tokenOffset = $m[0][1];
 			if ( $m[1][0] != '' ) {
 				if ( $foundStart &&
-				  $strcmp( $endDelim, substr( $subject, $tokenOffset, $endLength ) ) == 0 )
+					$strcmp( $endDelim, substr( $subject, $tokenOffset, $endLength ) ) == 0 )
 				{
 					# An end match is present at the same location
 					$tokenType = 'end';
@@ -155,12 +200,12 @@ class StringUtils {
 	 *
 	 *   preg_replace( "!$startDelim(.*)$endDelim!$flags", $replace, $subject )
 	 *
-	 * @param $startDelim String: start delimiter regular expression
-	 * @param $endDelim String: end delimiter regular expression
-	 * @param $replace String: replacement string. May contain $1, which will be
+	 * @param string $startDelim start delimiter regular expression
+	 * @param string $endDelim end delimiter regular expression
+	 * @param string $replace replacement string. May contain $1, which will be
 	 *                 replaced by the text between the delimiters
-	 * @param $subject String to search
-	 * @param $flags String: regular expression flags
+	 * @param string $subject to search
+	 * @param string $flags regular expression flags
 	 * @return String: The string with the matches replaced
 	 */
 	static function delimiterReplace( $startDelim, $endDelim, $replace, $subject, $flags = '' ) {
@@ -360,7 +405,7 @@ class ReplacementArray {
 	/**
 	 * Set an element of the replacement array
 	 * @param $from string
-	 * @param $to stromg
+	 * @param $to string
 	 */
 	function setPair( $from, $to ) {
 		$this->data[$from] = $to;
@@ -387,7 +432,7 @@ class ReplacementArray {
 	 * @param $from string
 	 */
 	function removePair( $from ) {
-		unset($this->data[$from]);
+		unset( $this->data[$from] );
 		$this->fss = false;
 	}
 
@@ -424,7 +469,7 @@ class ReplacementArray {
 
 /**
  * An iterator which works exactly like:
- * 
+ *
  * foreach ( explode( $delim, $s ) as $element ) {
  *    ...
  * }