eplacement character.
		 *
		 * > This practice is more secure because it does not result in the
		 * > conversion consuming parts of valid sequences as though they were
		 * > invalid. It also guarantees at least one replacement character will
		 * > occur for each instance of an invalid sequence in the original text.
		 * > Furthermore, this practice can be defined consistently for better
		 * > interoperability between different implementations of conversion.
		 *
		 * @see https://www.unicode.org/versions/Unicode16.0.0/core-spec/chapter-5/#G40630
		 */
		invalid_utf8:
		$at             = $i;
		$invalid_length = 1;

		// Single-byte and two-byte characters.
		if ( ( 0x00 === ( $b1 & 0x80 ) ) || ( 0xC0 === ( $b1 & 0xE0 ) ) ) {
			return $count;
		}

		$b2 = ord( $bytes[ $i + 1 ] ?? "\xC0" );
		$b3 = ord( $bytes[ $i + 2 ] ?? "\xC0" );

		// Find the maximal subpart and skip past it.
		if ( 0xE0 === ( $b1 & 0xF0 ) ) {
			// Three-byte characters.
			$b2_valid = (
				( 0xE0 === $b1 && $b2 >= 0xA0 && $b2 <= 0xBF ) ||
				( $b1 >= 0xE1 && $b1 <= 0xEC && $b2 >= 0x80 && $b2 <= 0xBF ) ||
				( 0xED === $b1 && $b2 >= 0x80 && $b2 <= 0x9F ) ||
				( $b1 >= 0xEE && $b1 <= 0xEF && $b2 >= 0x80 && $b2 <= 0xBF )
			);

			$invalid_length = min( $end - $i, $b2_valid ? 2 : 1 );
			return $count;
		} elseif ( 0xF0 === ( $b1 & 0xF8 ) ) {
			// Four-byte characters.
			$b2_valid = (
				( 0xF0 === $b1 && $b2 >= 0x90 && $b2 <= 0xBF ) ||
				( $b1 >= 0xF1 && $b1 <= 0xF3 && $b2 >= 0x80 && $b2 <= 0xBF ) ||
				( 0xF4 === $b1 && $b2 >= 0x80 && $b2 <= 0x8F )
			);

			$b3_valid = $b3 >= 0x80 && $b3 <= 0xBF;

			$invalid_length = min( $end - $i, $b2_valid ? ( $b3_valid ? 3 : 2 ) : 1 );
			return $count;
		}

		return $count;
	}

	$at = $i;
	return $count;
}

/**
 * Fallback mechanism for safely validating UTF-8 bytes.
 *
 * @since 6.9.0
 * @access private
 *
 * @see wp_is_valid_utf8()
 *
 * @param string $bytes String which might contain text encoded as UTF-8.
 * @return bool Whether the provided bytes can decode as valid UTF-8.
 */
function _wp_is_valid_utf8_fallback( string $bytes ): bool {
	$bytes_length = strlen( $bytes );
	if ( 0 === $bytes_length ) {
		return true;
	}

	$next_byte_at   = 0;
	$invalid_length = 0;

	_wp_scan_utf8( $bytes, $next_byte_at, $invalid_length );

	return $bytes_length === $next_byte_at && 0 === $invalid_length;
}

/**
 * Fallback mechanism for replacing invalid spans of UTF-8 bytes.
 *
 * Example:
 *
 *     'Pi�a' === _wp_scrub_utf8_fallback( "Pi\xF1a" ); // “ñ” is 0xF1 in Windows-1252.
 *
 * @since 6.9.0
 * @access private
 *
 * @see wp_scrub_utf8()
 *
 * @param string $bytes UTF-8 encoded string which might contain spans of invalid bytes.
 * @return string Input string with spans of invalid bytes swapped with the replacement character.
 */
function _wp_scrub_utf8_fallback( string $bytes ): string {
	$bytes_length   = strlen( $bytes );
	$next_byte_at   = 0;
	$was_at         = 0;
	$invalid_length = 0;
	$scrubbed       = '';

	while ( $next_byte_at <= $bytes_length ) {
		_wp_scan_utf8( $bytes, $next_byte_at, $invalid_length );

		if ( $next_byte_at >= $bytes_length ) {
			if ( 0 === $was_at ) {
				return $bytes;
			}

			return $scrubbed . substr( $bytes, $was_at, $next_byte_at - $was_at - $invalid_length );
		}

		$scrubbed .= substr( $bytes, $was_at, $next_byte_at - $was_at );
		$scrubbed .= "\u{FFFD}";

		$next_byte_at += $invalid_length;
		$was_at        = $next_byte_at;
	}

	return $scrubbed;
}

/**
 * Returns how many code points are found in the given UTF-8 string.
 *
 * Invalid spans of bytes count as a single code point according
 * to the maximal subpart rule. This function is a fallback method
 * for calling `mb_strlen( $text, 'UTF-8' )`.
 *
 * When negative values are provided for the byte offsets or length,
 * this will always report zero code points.
 *
 * Example:
 *
 *     4  === _wp_utf8_codepoint_count( 'text' );
 *
 *     // Groups are 'test', "\x90" as '�', 'wp', "\xE2\x80" as '�', "\xC0" as '�', and 'test'.
 *     13 === _wp_utf8_codepoint_count( "test\x90wp\xE2\x80\xC0test" );
 *
 * @since 6.9.0
 * @access private
 *
 * @param string $text            Count code points in this string.
 * @param ?int   $byte_offset     Start counting after this many bytes in `$text`. Must be positive.
 * @param ?int   $max_byte_length Optional. Stop counting after having scanned past this many bytes.
 *                                Default is to scan until the end of the string. Must be positive.
 * @return int How many code points were found.
 */
function _wp_utf8_codepoint_count( string $text, ?int $byte_offset = 0, ?int $max_byte_length = PHP_INT_MAX ): int {
	if ( $byte_offset < 0 ) {
		return 0;
	}

	$count           = 0;
	$at              = $byte_offset;
	$end             = strlen( $text );
	$invalid_length  = 0;
	$max_byte_length = min( $end - $at, $max_byte_length );

	while ( $at < $end && ( $at - $byte_offset ) < $max_byte_length ) {
		$count += _wp_scan_utf8( $text, $at, $invalid_length, $max_byte_length - ( $at - $byte_offset ) );
		$count += $invalid_length > 0 ? 1 : 0;
		$at    += $invalid_length;
	}

	return $count;
}

/**
 * Given a starting offset within a string and a maximum number of code points,
 * return how many bytes are occupied by the span of characters.
 *
 * Invalid spans of bytes count as a single code point according to the maximal
 * subpart rule. This function is a fallback method for calling
 * `strlen( mb_substr( substr( $text, $at ), 0, $max_code_points ) )`.
 *
 * @since 6.9.0
 * @access private
 *
 * @param string $text              Count bytes of span in this text.
 * @param int    $byte_offset       Start counting at this byte offset.
 * @param int    $max_code_points   Stop counting after this many code points have been seen,
 *                                  or at the end of the string.
 * @param ?int   $found_code_points Optional. Will be set to number of found code points in
 *                                  span, as this might be smaller than the maximum count if
 *                                  the string is not long enough.
 * @return int Number of bytes spanned by the code points.
 */
function _wp_utf8_codepoint_span( string $text, int $byte_offset, int $max_code_points, ?int &$found_code_points = 0 ): int {
	$was_at            = $byte_offset;
	$invalid_length    = 0;
	$end               = strlen( $text );
	$found_code_points = 0;

	while ( $byte_offset < $end && $found_code_points < $max_code_points ) {
		$needed      = $max_code_points - $found_code_points;
		$chunk_count = _wp_scan_utf8( $text, $byte_offset, $invalid_length, null, $needed );

		$found_code_points += $chunk_count;

		// Invalid spans only convey one code point count regardless of how long they are.
		if ( 0 !== $invalid_length && $found_code_points < $max_code_points ) {
			++$found_code_points;
			$byte_offset += $invalid_length;
		}
	}

	return $byte_offset - $was_at;
}

/**
 * Fallback support for determining if a string contains Unicode noncharacters.
 *
 * @since 6.9.0
 * @access private
 *
 * @see \wp_has_noncharacters()
 *
 * @param string $text Are there noncharacters in this string?
 * @return bool Whether noncharacters were found in the string.
 */
function _wp_has_noncharacters_fallback( string $text ): bool {
	$at                = 0;
	$invalid_length    = 0;
	$has_noncharacters = false;
	$end               = strlen( $text );

	while ( $at < $end && ! $has_noncharacters ) {
		_wp_scan_utf8( $text, $at, $invalid_length, null, null, $has_noncharacters );
		$at += $invalid_length;
	}

	return $has_noncharacters;
}

/**
 * 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;
}
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 with Sodium in PHP 7.2, but the extension may not be enabled.
if ( ! function_exists( 'sodium_crypto_box' ) ) {
	require ABSPATH . WPINC . '/sodium_compat/autoload.php';
}

if ( ! function_exists( 'array_is_list' ) ) {
	/**
	 * Polyfill for `array_is_list()` function added in PHP 8.1.
	 *
	 * Determines if the given array is a list.
	 *
	 * An array is considered a list if its keys consist of consecutive numbers from 0 to count($array)-1.
	 *
	 * @see https://github.com/symfony/polyfill-php81/tree/main
	 *
	 * @since 6.5.0
	 *
	 * @param array<mixed> $arr The array being evaluated.
	 * @return bool True if array is a list, false otherwise.
	 */
	function array_is_list( $arr ) {
		if ( ( array() === $arr ) || ( array_values( $arr ) === $arr ) ) {
			return true;
		}

		$next_key = -1;

		foreach ( $arr as $k => $v ) {
			if ( ++$next_key !== $k ) {
				return false;
			}
		}

		return true;
	}
}

if ( ! function_exists( 'str_contains' ) ) {
	/**
	 * Polyfill for `str_contains()` function added in PHP 8.0.
	 *
	 * Performs a case-sensitive check indicating if needle is
	 * contained in haystack.
	 *
	 * @since 5.9.0
	 *
	 * @param string $haystack The string to search in.
	 * @param string $needle   The substring to search for in the `$haystack`.
	 * @return bool True if `$needle` is in `$haystack`, otherwise false.
	 */
	function str_contains( $haystack, $needle ) {
		if ( '' === $needle ) {
			return true;
		}

		return false !== strpos( $haystack, $needle );
	}
}

if ( ! function_exists( 'str_starts_with' ) ) {
	/**
	 * Polyfill for `str_starts_with()` function added in PHP 8.0.
	 *
	 * Performs a case-sensitive check indicating if
	 * the haystack begins with needle.
	 *
	 * @since 5.9.0
	 *
	 * @param string $haystack The string to search in.
	 * @param string $needle   The substring to search for in the `$haystack`.
	 * @return bool True if `$haystack` starts with `$needle`, otherwise false.
	 */
	function str_starts_with( $haystack, $needle ) {
		if ( '' === $needle ) {
			return true;
		}

		return 0 === strpos( $haystack, $needle );
	}
}

if ( ! function_exists( 'str_ends_with' ) ) {
	/**
	 * Polyfill for `str_ends_with()` function added in PHP 8.0.
	 *
	 * Performs a case-sensitive check indicating if
	 * the haystack ends with needle.
	 *
	 * @since 5.9.0
	 *
	 * @param string $haystack The string to search in.
	 * @param string $needle   The substring to search for in the `$haystack`.
	 * @return bool True if `$haystack` ends with `$needle`, otherwise false.
	 */
	function str_ends_with( $haystack, $needle ) {
		if ( '' === $haystack ) {
			return '' === $needle;
		}

		$len = strlen( $needle );

		return substr( $haystack, -$len, $len ) === $needle;
	}
}

if ( ! function_exists( 'array_find' ) ) {
	/**
	 * Polyfill for `array_find()` function added in PHP 8.4.
	 *
	 * Searches an array for the first element that passes a given callback.
	 *
	 * @since 6.8.0
	 *
	 * @param array    $array    The array to search.
	 * @param callable $callback The callback to run for each element.
	 * @return mixed|null The first element in the array that passes the `$callback`, otherwise null.
	 */
	function array_find( array $array, callable $callback ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
		foreach ( $array as $key => $value ) {
			if ( $callback( $value, $key ) ) {
				return $value;
			}
		}

		return null;
	}
}

if ( ! function_exists( 'array_find_key' ) ) {
	/**
	 * Polyfill for `array_find_key()` function added in PHP 8.4.
	 *
	 * Searches an array for the first key that passes a given callback.
	 *
	 * @since 6.8.0
	 *
	 * @param array    $array    The array to search.
	 * @param callable $callback The callback to run for each element.
	 * @return int|string|null The first key in the array that passes the `$callback`, otherwise null.
	 */
	function array_find_key( array $array, callable $callback ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
		foreach ( $array as $key => $value ) {
			if ( $callback( $value, $key ) ) {
				return $key;
			}
		}

		return null;
	}
}

if ( ! function_exists( 'array_any' ) ) {
	/**
	 * Polyfill for `array_any()` function added in PHP 8.4.
	 *
	 * Checks if any element of an array passes a given callback.
	 *
	 * @since 6.8.0
	 *
	 * @param array    $array    The array to check.
	 * @param callable $callback The callback to run for each element.
	 * @return bool True if any element in the array passes the `$callback`, otherwise false.
	 */
	function array_any( array $array, callable $callback ): bool { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
		foreach ( $array as $key => $value ) {
			if ( $callback( $value, $key ) ) {
				return true;
			}
		}

		return false;
	}
}

if ( ! function_exists( 'array_all' ) ) {
	/**
	 * Polyfill for `array_all()` function added in PHP 8.4.
	 *
	 * Checks if all elements of an array pass a given callback.
	 *
	 * @since 6.8.0
	 *
	 * @param array    $array    The array to check.
	 * @param callable $callback The callback to run for each element.
	 * @return bool True if all elements in the array pass the `$callback`, otherwise false.
	 */
	function array_all( array $array, callable $callback ): bool { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
		foreach ( $array as $key => $value ) {
			if ( ! $callback( $value, $key ) ) {
				return false;
			}
		}

		return true;
	}
}

if ( ! function_exists( 'array_first' ) ) {
	/**
	 * Polyfill for `array_first()` function added in PHP 8.5.
	 *
	 * Returns the first element of an array.
	 *
	 * @since 6.9.0
	 *
	 * @param array $array The array to get the first element from.
	 * @return mixed|null The first element of the array, or null if the array is empty.
	 */
	function array_first( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
		if ( empty( $array ) ) {
			return null;
		}

		foreach ( $array as $value ) {
			return $value;
		}
	}
}

if ( ! function_exists( 'array_last' ) ) {
	/**
	 * Polyfill for `array_last()` function added in PHP 8.5.
	 *
	 * Returns the last element of an array.
	 *
	 * @since 6.9.0
	 *
	 * @param array $array The array to get the last element from.
	 * @return mixed|null The last element of the array, or null if the array is empty.
	 */
	function array_last( array $array ) { // phpcs:ignore Universal.NamingConventions.NoReservedKeywordParameterNames.arrayFound
		if ( empty( $array ) ) {
			return null;
		}

		return $array[ array_key_last( $array ) ];
	}
}

// IMAGETYPE_AVIF constant is only defined in PHP 8.x or later.
if ( ! defined( 'IMAGETYPE_AVIF' ) ) {
	define( 'IMAGETYPE_AVIF', 19 );
}

// IMG_AVIF constant is only defined in PHP 8.x or later.
if ( ! defined( 'IMG_AVIF' ) ) {
	define( 'IMG_AVIF', IMAGETYPE_AVIF );
}

// IMAGETYPE_HEIF constant is only defined in PHP 8.5 or later.
if ( ! defined( 'IMAGETYPE_HEIF' ) ) {
	define( 'IMAGETYPE_HEIF', 20 );
}
 '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( '