1286502 - Email content is not shown at all when using application/pkcs7-signature

Status: UNCONFIRMED

(Thunderbird :: Message Reader UI, defect)

Description

[Omen]

Attachment: Email source code and screenshots

User Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:47.0) Gecko/20100101 Firefox/47.0
Build ID: 20160604131506

Steps to reproduce:

Since several months I've experienced constant problem with displaying the emails from my bank (but not only that). I thought it is a problem of the bank sending service, but finally I've found that the email source code seems to be correct. 
I believe the issue concerns "application/pkcs7-signature", because all issues I experience concerns the mails having such protocol in Content-Type header defined.
I attach an example email source code for reference (exampleEmail.eml) - I've modified my personal data in it, so the signature of this email will be detected as an incorrect, but originally it was fine (if the trusted developer needs it, I can provide the original source code on priv).

When I forward that mail to the same mailbox, or write it to disk and open manually by Thunderbird, then it works fine. 

Furthermore... once I open manually such email written to disk, Thunderbird starts to display all similar problematic emails in my inbox correctly as well, and it works fine until I restart Thunderbird.


Actual results:

Content of an email that is listed my Inbox, nor when I double click it to open in separate window, is not displayed at all (see emailNoContent.png attached). I attach a screenshot of such situation.
Also, if an email contains some attachments, they are not presented as available for download or preview.

Once it starts working (opened manually some of such emails from the disk) it looks like on attachment emailCorrectlyDisplayed.png.


Expected results:

It should display an email properly.