Attachment name is not searched correctly

[GoogleCodeExporter]

What steps will reproduce the problem?
email of the following format, excerpt:

Content-Type: application/vnd.openxmlformats...bla-bla;
    name="=?UTF-8?B?MTQw...bla-bla=?="
Content-Disposition: attachment
Content-Transfer-Encoding: base64

Here the file content starts...


What is the expected output? What do you see instead?
Expected output is the actual file name which is given on line #2. There is a 
random filename is coming out instead being generated by:

public function getAttachments() {
...
    $part['disposition-filename'] = md5(uniqid());
...


}

What version of the product are you using? On what operating system?
r27, Linux Ubuntu, PHP 5

Please provide any additional information below.
The file name do exists in the file just one line above the script is looking 
for.

Original issue reported on code.google.com by [email protected] on 6 Mar 2014 at 3:58