lib/Dropbox/Util.php
public static function stripUtf8Bom($string)
    {
        if (strlen($string) == 0) return $string;

        if (\substr_compare($string, "\xEF\xBB\xBF", 0, 3) === 0) {
            $string = \substr($string, 3);
        }
        return $string;
    }
public static function stripUtf8Bom($string)
    {
        if (strlen($string) == 0) return $string;

        if (\substr_compare($string, "\xEF\xBB\xBF", 0, 3) === 0) {
            $string = \substr($string, 3);
        }
        return $string;
    }
If the given string begins with the UTF-8 BOM (byte order mark), remove it and
return whatever is left.  Otherwise, return the original string untouched.

Though it's not recommended for UTF-8 to have a BOM, the standard allows it to
support software that isn't Unicode-aware.

@param string $string
A UTF-8 encoded string.

@return string