[imp] IMP is breaking certain attachments.

[Adam Tauno Williams]

Horde 3.3.4 / IMAP H3 4.3.4 / PHP 5.2.12
PEAR: Mail_Mime 1.8.0 Fileinfo 1.0.4

I'm having an issue where certain files attached to messages in IMP get
corrupted. Almost all files work. But for some files, I believe, IMP is
not base64 encoding them.  On the corrupted files the message source
looks like : 

--=_52mp429tmh8o
Content-Type: text/base64;
 charset=UTF-8;
 name="Nov17-120851.pdf"
Content-Disposition: attachment;
 filename="Nov17-120851.pdf"
Content-Transfer-Encoding: quoted-printable

%PDF-1.2
%=C7=EC=8F=A2
5 0 obj
<</Length 6 0 R/Filter /FlateDecode>>
stream
x=9C=B5TKo=141=0C=16=D0=D2v=A8

If I send the same file from the same place using Evolution the message
source looks like the following and the attachment is valid -

--=-FUqo8thPdax4QuBo+m5u 
Content-Type: application/pdf; name="Nov17-120851.pdf"
Content-Disposition: attachment; filename="Nov17-120851.pdf"
Content-Transfer-Encoding: base64

JVBERi0xLjIKJcfsj6IKNSAwIG9iago8PC9MZW5ndGggNiAwIFIvRmlsdGVyIC9GbGF0ZURlY29k
ZT4+CnN0cmVhbQp4nLVUS28UMQwW0NJ2qAoUyvuR8owPY+K8c0UgJG6tRuJAeyoCDt2i7f8/4JnZ

But IMP does encode other messages correctly, like -

--=_3wzm200uoccg
Content-Type: application/x-zip;
 name="groupdav-2.5.s4j"
Content-Disposition: attachment;
 filename="groupdav-2.5.s4j"
Content-Transfer-Encoding: base64

UEsDBAoAAAAAAO6jPzwAAAAAAAAAAAAAAAAJAAQATUVUQS1JTkYv/soAAFBLAwQKAAAACADtoz88


It isn't just PDF-files-do-not-attach, some PDF files do.  I've tried
these files on Windows, LINUX, attaching from different folders, etc...
The broken attachments do appear as different sizes than files that are
correctly attached.