Description:
------------
Any file upload scripts on 2 seperate servers that allow PDF uploads are resulting in a mime type of application/x-pilot which is obviously incorrect.  We tested with numerous PDF files as well as on 2 seperate servers.  One Fedora Linux and one RedHat Linux.  Both used v5.1.6 initially, we then upgraded to 5.2.1 with the same problem.  

Reproduce code:
---------------
<form method="post" enctype="multipart/form-data">
<input type="file" name="myfile">
<input type="submit" name="submit" value="submit">
</form>

<?php

if (isset($_POST['submit'])) {
    print_r($_FILES);
}

?>


Expected result:
----------------
Array
(
    [myfile] => Array
        (
            [name] => bdbxml.pdf
            [type] => application/pdf
            [tmp_name] => /tmp/php9OEgjj
            [error] => 0
            [size] => 145709
        )

)

Actual result:
--------------
Array
(
    [myfile] => Array
        (
            [name] => bdbxml.pdf
            [type] => application/x-pilot
            [tmp_name] => /tmp/php9OEgjj
            [error] => 0
            [size] => 145709
        )

)