134114 - MDN: mime type for MDN attachemnts (.txt) is not recognized when you double click on them

Status: NEW

(MailNews Core :: Backend, defect)

Description

[grylchan]

Using Seth's test builds on windows, linux, and Mac.

I noticed if you double click any of the 2 mdn files
(MDNPart2.txt or MDNPart3.txt) on the attachment section
of your return receipt mesg, instead of being able
to read that attachment file in the browser or your text
editor, you are prompted with download window to either
save it or choose an application to open it with.

But if I do the same steps with a email mesg that contains a text
file it works and it is opened in the browser.

Steps to reproduce:
1.Request a return receipt
2.Send a mesg w/return receipt
3.Get the return receipt after the user has read your mesg
4.Double click on MDNPart2.txt or MDN Part3.txt in attachment section.

Result: Download window appears
expected: to view the text file in the browser

I spoke to Seth, offline on this and these are his comments:
> Yes, I think it's a bug.
> The mime types for those attachments are:
> Content-Type: message/disposition-notification;
> and
> Content-Type: text/rfc822-headers;
> see mozilla\mailnews\extensions\mdn\src\nsMsgMdnGenerator.cpp
> I think we're going to have to make mozilla handle those mime
> types by
> default to prevent the problem you've found.
> This should be an easy fix to a mime types file.
> The browser should be able to view those mime types, as they are
> just
> plain text files.

I assigned it to you Jeff, if it should be Seth than please
reassign.

Comment 1

[Jeff Tsai]

Accepting ...

Comment 2

[(not reading, please use [e-mail] instead)]

my initial guess would be to look in

mozilla\netwerk\mime\public\nsMimeTypes.h
mozilla\netwerk\mime\src\nsXMLMIMEDataSource.cpp
mozilla\uriloader\exthandler\nsExternalHelperAppService.cpp

for where to fix this.

Comment 3

[grylchan]

nominating in case people do double click the attachment
and expect it to open in text file instead of the
failure we get.

Granted they can still read both attachments in body of
the return receipt mesg so they don't necessarily need
to double click attachment. 

Comment 4

[buovjaga]

Still repro.

Thunderbird 52.0.1 (32-bit)
Windows 7 64-bit