wp-includes/PHPMailer/PHPMailer.php:5132Detect if a string contains a line longer than the maximum line length allowed by RFC 2822 section 2.1.1.
$strstringbool public static function hasLineLongerThanMax($str) { return (bool) preg_match('/^(.{' . (self::MAX_LINE_LENGTH + strlen(static::$LE)) . ',})/m', $str); }Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/PHPMailer/PHPMailer.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.