Changeset 32364 for trunk/src/wp-includes/compat.php

Timestamp:

05/06/2015 02:59:50 AM (10 years ago)

Author:

pento

Message:

WPDB: When checking that a string can be sent to MySQL, we shouldn't use mb_convert_encoding(), as it behaves differently to MySQL's character encoding conversion.

Props mdawaffe, pento, nbachiyski, jorbin, johnjamesjacoby, jeremyfelt.

See #32165.

File:

• trunk/src/wp-includes/compat.php (modified) (3 diffs)

trunk/src/wp-includes/compat.php

@@ -14 +14 @@
 }
 
+/**
+ * Returns whether PCRE/u (PCRE_UTF8 modifier) is available for use.
+ *
+ * @ignore
+ * @since 4.2.2
+ * @access private
+ *
+ * @param bool $set - Used for testing only
+ *             null   : default - get PCRE/u capability
+ *             false  : Used for testing - return false for future calls to this function
+ *             'reset': Used for testing - restore default behavior of this function
+ */
+function _wp_can_use_pcre_u( $set = null ) {
+    static $utf8_pcre = 'reset';
+
+    if ( null !== $set ) {
+        $utf8_pcre = $set;
+    }
+
+    if ( 'reset' === $utf8_pcre ) {
+        $utf8_pcre = @preg_match( '/^./u', 'a' );
+    }
+
+    return $utf8_pcre;
+}
+
 if ( ! function_exists( 'mb_substr' ) ) :
     function mb_substr( $str, $start, $length = null, $encoding = null ) {
@@ -20 +46 @@
 endif;
 
+/*
+ * Only understands UTF-8 and 8bit.  All other character sets will be treated as 8bit.
+ * For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
+ * The behavior of this function for invalid inputs is undefined.
+ */
 function _mb_substr( $str, $start, $length = null, $encoding = null ) {
+    if ( null === $encoding ) {
+        $encoding = get_option( 'blog_charset' );
+    }
+
     // The solution below works only for UTF-8,
     // so in case of a different charset just use built-in substr()
-    $charset = get_option( 'blog_charset' );
-    if ( ! in_array( $charset, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
+    if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
         return is_null( $length ) ? substr( $str, $start ) : substr( $str, $start, $length );
     }
-    // Use the regex unicode support to separate the UTF-8 characters into an array
-    preg_match_all( '/./us', $str, $match );
-    $chars = is_null( $length ) ? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length );
-    return implode( '', $chars );
+
+    if ( _wp_can_use_pcre_u() ) {
+        // Use the regex unicode support to separate the UTF-8 characters into an array
+        preg_match_all( '/./us', $str, $match );
+        $chars = is_null( $length ) ? array_slice( $match[0], $start ) : array_slice( $match[0], $start, $length );
+        return implode( '', $chars );
+    }
+
+    $regex = '/(
+          [\x00-\x7F]                  # single-byte sequences   0xxxxxxx
+        | [\xC2-\xDF][\x80-\xBF]       # double-byte sequences   110xxxxx 10xxxxxx
+        | \xE0[\xA0-\xBF][\x80-\xBF]   # triple-byte sequences   1110xxxx 10xxxxxx * 2
+        | [\xE1-\xEC][\x80-\xBF]{2}
+        | \xED[\x80-\x9F][\x80-\xBF]
+        | [\xEE-\xEF][\x80-\xBF]{2}
+        | \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3
+        | [\xF1-\xF3][\x80-\xBF]{3}
+        | \xF4[\x80-\x8F][\x80-\xBF]{2}
+    )/x';
+
+    $chars = array( '' ); // Start with 1 element instead of 0 since the first thing we do is pop
+    do {
+        // We had some string left over from the last round, but we counted it in that last round.
+        array_pop( $chars );
+
+        // Split by UTF-8 character, limit to 1000 characters (last array element will contain the rest of the string)
+        $pieces = preg_split( $regex, $str, 1000, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY );
+
+        $chars = array_merge( $chars, $pieces );
+    } while ( count( $pieces ) > 1 && $str = array_pop( $pieces ) ); // If there's anything left over, repeat the loop.
+
+    return join( '', array_slice( $chars, $start, $length ) );
 }
 
@@ -39 +101 @@
 endif;
 
+/*
+ * Only understands UTF-8 and 8bit.  All other character sets will be treated as 8bit.
+ * For $encoding === UTF-8, the $str input is expected to be a valid UTF-8 byte sequence.
+ * The behavior of this function for invalid inputs is undefined.
+ */
 function _mb_strlen( $str, $encoding = null ) {
+    if ( null === $encoding ) {
+        $encoding = get_option( 'blog_charset' );
+    }
+
     // The solution below works only for UTF-8,
     // so in case of a different charset just use built-in strlen()
-    $charset = get_option( 'blog_charset' );
-    if ( ! in_array( $charset, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
+    if ( ! in_array( $encoding, array( 'utf8', 'utf-8', 'UTF8', 'UTF-8' ) ) ) {
         return strlen( $str );
     }
-    // Use the regex unicode support to separate the UTF-8 characters into an array
-    preg_match_all( '/./us', $str, $match );
-    return count( $match[0] );
+
+    if ( _wp_can_use_pcre_u() ) {
+        // Use the regex unicode support to separate the UTF-8 characters into an array
+        preg_match_all( '/./us', $str, $match );
+        return count( $match[0] );
+    }
+
+    $regex = '/(?:
+          [\x00-\x7F]                  # single-byte sequences   0xxxxxxx
+        | [\xC2-\xDF][\x80-\xBF]       # double-byte sequences   110xxxxx 10xxxxxx
+        | \xE0[\xA0-\xBF][\x80-\xBF]   # triple-byte sequences   1110xxxx 10xxxxxx * 2
+        | [\xE1-\xEC][\x80-\xBF]{2}
+        | \xED[\x80-\x9F][\x80-\xBF]
+        | [\xEE-\xEF][\x80-\xBF]{2}
+        | \xF0[\x90-\xBF][\x80-\xBF]{2} # four-byte sequences   11110xxx 10xxxxxx * 3
+        | [\xF1-\xF3][\x80-\xBF]{3}
+        | \xF4[\x80-\x8F][\x80-\xBF]{2}
+    )/x';
+
+    $count = 1; // Start at 1 instead of 0 since the first thing we do is decrement
+    do {
+        // We had some string left over from the last round, but we counted it in that last round.
+        $count--;
+
+        // Split by UTF-8 character, limit to 1000 characters (last array element will contain the rest of the string)
+        $pieces = preg_split( $regex, $str, 1000 );
+
+        // Increment
+        $count += count( $pieces );
+    } while ( $str = array_pop( $pieces ) ); // If there's anything left over, repeat the loop.
+
+    // Fencepost: preg_split() always returns one extra item in the array
+    return --$count;
 }