Changeset 60950

Timestamp:

10/16/2025 11:17:14 PM (11 months ago)

Author:

dmsnell

Message:

Charset: Conditionally polyfill utf8_encode() and utf8_decode().

The utf8_encode() and utf8_decode() functions were deprecated in PHP 8.2.0 and will be removed in PHP 9.0. When that happens, any existing code which calls them will trigger a crash.

This patch introduces polyfills for those functions when they aren’t already present. The polyfill functions maintain backwards compatibility, including a deprecation notice.

Any code calling either of these functions ought to be refactored to avoid using them; there are better options which don’t carry the issues these functions do, and any code calling them is likely calling them inappropriately.

Developed in ​https://github.com/WordPress/wordpress-develop/pull/10011
Discussed in https://core.trac.wordpress.org/ticket/55603
Discussed in https://core.trac.wordpress.org/ticket/63863

See #63863.

Location:

trunk

Files:

• src/wp-includes/compat-utf8.php (modified) (1 diff)
• src/wp-includes/compat.php (modified) (1 diff)
• tests/phpunit/tests/formatting/deprecatedUtfEncodeDecode.php (added)

trunk/src/wp-includes/compat-utf8.php

@@ -338 +338 @@
         return $count;
 }
+
+/**
+ * Converts a string from ISO-8859-1 to UTF-8, maintaining backwards compatibility
+ * with the deprecated function from the PHP standard library.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @see \utf8_encode()
+ *
+ * @param string $iso_8859_1_text Text treated as ISO-8859-1 (latin1) bytes.
+ * @return string Text converted into UTF-8.
+ */
+function _wp_utf8_encode_fallback( $iso_8859_1_text ) {
+        $iso_8859_1_text = (string) $iso_8859_1_text;
+        $at              = 0;
+        $was_at          = 0;
+        $end             = strlen( $iso_8859_1_text );
+        $utf8            = '';
+
+        while ( $at < $end ) {
+                // US-ASCII bytes are identical in ISO-8859-1 and UTF-8. These are 0x00–0x7F.
+                $ascii_byte_count = strspn(
+                        $iso_8859_1_text,
+                        "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" .
+                        "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" .
+                        " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f",
+                        $at
+                );
+
+                if ( $ascii_byte_count > 0 ) {
+                        $at += $ascii_byte_count;
+                        continue;
+                }
+
+                // All other bytes transform into two-byte UTF-8 sequences.
+                $code_point = ord( $iso_8859_1_text[ $at ] );
+                $byte1      = chr( 0xC0 | ( $code_point >> 6 ) );
+                $byte2      = chr( 0x80 | ( $code_point & 0x3F ) );
+
+                $utf8 .= substr( $iso_8859_1_text, $was_at, $at - $was_at );
+                $utf8 .= "{$byte1}{$byte2}";
+
+                ++$at;
+                $was_at = $at;
+        }
+
+        if ( 0 === $was_at ) {
+                return $iso_8859_1_text;
+        }
+
+        $utf8 .= substr( $iso_8859_1_text, $was_at );
+        return $utf8;
+}
+
+/**
+ * Converts a string from UTF-8 to ISO-8859-1, maintaining backwards compatibility
+ * with the deprecated function from the PHP standard library.
+ *
+ * @since 6.9.0
+ * @access private
+ *
+ * @see \utf8_decode()
+ *
+ * @param string $utf8_text Text treated as UTF-8 bytes.
+ * @return string Text converted into ISO-8859-1.
+ */
+function _wp_utf8_decode_fallback( $utf8_text ) {
+        $utf8_text       = (string) $utf8_text;
+        $at              = 0;
+        $was_at          = 0;
+        $end             = strlen( $utf8_text );
+        $iso_8859_1_text = '';
+
+        while ( $at < $end ) {
+                // US-ASCII bytes are identical in ISO-8859-1 and UTF-8. These are 0x00–0x7F.
+                $ascii_byte_count = strspn(
+                        $utf8_text,
+                        "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f" .
+                        "\x10\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f" .
+                        " !\"#$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\\]^_`abcdefghijklmnopqrstuvwxyz{|}~\x7f",
+                        $at
+                );
+
+                if ( $ascii_byte_count > 0 ) {
+                        $at += $ascii_byte_count;
+                        continue;
+                }
+
+                $next_at        = $at;
+                $invalid_length = 0;
+                $found          = _wp_scan_utf8( $utf8_text, $next_at, $invalid_length, null, 1 );
+                $span_length    = $next_at - $at;
+                $next_byte      = '?';
+
+                if ( 1 !== $found ) {
+                        if ( $invalid_length > 0 ) {
+                                $next_byte = '';
+                                goto flush_sub_part;
+                        }
+
+                        break;
+                }
+
+                // All convertible code points are two-bytes long.
+                $byte1 = ord( $utf8_text[ $at ] );
+                if ( 0xC0 !== ( $byte1 & 0xE0 ) ) {
+                        goto flush_sub_part;
+                }
+
+                // All convertible code points are not greater than U+FF.
+                $byte2 = ord( $utf8_text[ $at + 1 ] );
+                $code_point = ( ( $byte1 & 0x1F ) << 6 ) | ( ( $byte2 & 0x3F ) );
+                if ( $code_point > 0xFF ) {
+                        goto flush_sub_part;
+                }
+
+                $next_byte = chr( $code_point );
+
+                flush_sub_part:
+                $iso_8859_1_text .= substr( $utf8_text, $was_at, $at - $was_at );
+                $iso_8859_1_text .= $next_byte;
+                $at              += $span_length;
+                $was_at           = $at;
+
+                if ( $invalid_length > 0 ) {
+                        $iso_8859_1_text .= '?';
+                        $at              += $invalid_length;
+                        $was_at           = $at;
+                }
+        }
+
+        if ( 0 === $was_at ) {
+                return $utf8_text;
+        }
+
+        $iso_8859_1_text .= substr( $utf8_text, $was_at );
+        return $iso_8859_1_text;
+}

trunk/src/wp-includes/compat.php

@@ -248 +248 @@
 }
 
+if ( ! function_exists( 'utf8_encode' ) ) :
+        if ( extension_loaded( 'mbstring' ) ) :
+                /**
+                 * Converts a string from ISO-8859-1 to UTF-8.
+                 *
+                 * @deprecated Use {@see \mb_convert_encoding()} instead.
+                 *
+                 * @since 6.9.0
+                 *
+                 * @param string $iso_8859_1_text Text treated as ISO-8859-1 (latin1) bytes.
+                 * @return string Text converted into a UTF-8.
+                 */
+                function utf8_encode( $iso_8859_1_text ): string {
+                        _deprecated_function( __FUNCTION__, '6.9.0', 'mb_convert_encoding' );
+
+                        return mb_convert_encoding( $iso_8859_1_text, 'UTF-8', 'ISO-8859-1' );
+                }
+
+        else :
+                /**
+                 * @ignore
+                 * @private
+                 *
+                 * @since 6.9.0
+                 */
+                function utf8_encode( $iso_8859_1_text ): string {
+                        _deprecated_function( __FUNCTION__, '6.9.0', 'mb_convert_encoding' );
+
+                        return _wp_utf8_encode_fallback( $iso_8859_1_text );
+                }
+
+        endif;
+endif;
+
+if ( ! function_exists( 'utf8_decode' ) ) :
+        if ( extension_loaded( 'mbstring' ) ) :
+                /**
+                 * Converts a string from UTF-8 to ISO-8859-1.
+                 *
+                 * @deprecated Use {@see \mb_convert_encoding()} instead.
+                 *
+                 * @since 6.9.0
+                 *
+                 * @param string $utf8_text Text treated as UTF-8.
+                 * @return string Text converted into ISO-8859-1.
+                 */
+                function utf8_decode( $utf8_text ): string {
+                        _deprecated_function( __FUNCTION__, '6.9.0', 'mb_convert_encoding' );
+
+                        return mb_convert_encoding( $utf8_text, 'ISO-8859-1', 'UTF-8' );
+                }
+
+        else :
+                /**
+                 * @ignore
+                 * @private
+                 *
+                 * @since 6.9.0
+                 */
+                function utf8_decode( $utf8_text ): string {
+                        _deprecated_function( __FUNCTION__, '6.9.0', 'mb_convert_encoding' );
+
+                        return _wp_utf8_decode_fallback( $utf8_text );
+                }
+
+        endif;
+endif;
+
 // sodium_crypto_box() was introduced in PHP 7.2.
 if ( ! function_exists( 'sodium_crypto_box' ) ) {