_wp_is_valid_utf8_fallback()

_wp_is_valid_utf8_fallback( string $bytes ): bool

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;
}