1235240 - Detach Attachment.png replaces attached picture by "detached" header information, but keeps image name; Edit as New mail will contain destroyed pictures

Status: UNCONFIRMED

(SeaMonkey :: MailNews: Backend, defect)

Description

[Rainer Bielefeld]

Attachment: Test Mail with PNG pictures as attachments

Steps how to reproduce with  SeaMonkey German 2.39 final Mozilla/5.0 (Windows NT 6.1; WOW64; rv:42.0 from official download area)  Gecko/20100101  Firefox/42.0  Build 20151103191810  (Classic Theme) on German WIN7 64bit

0. Import and open  attached email (what will be difficult because 
   of Bug 684924)
   or create a new one with 3 simple small pictures as attachments
2. Send that email to an own email account
3. Click received mail in Thread Pane
4. In Mail View Pane / attachments list pane in grey mail header view
   select all 3 attachments, 'rightlick attachments → 
   Detach → confirm warning and save'
   » All selected files will be saved as expected
   Expected: no longer attachments shown
   Actual:  all 3 file names will remain in attachments list pane

Additional Tests

5. In received mail open picture attachments by double click:
   » Pictures will be opened in Browser and show expected pictures
6. Compare email source text of sent mail and received mail:
   » Sent mail will contain 3 binary blocks for pictures
   » Received mail will contain 3 hints that attachment has been 
7. 'Rightclick received mail in Inbox Thread Pane → Edit as New → 
   » Attachments list pane still will show 3 .png files, but with
     unexpected small file sizes
   » double click on attachment will try to open a picture in browser,
     but fails with error message. Mail Source examination in a 
     saved draft copy will show that binary blocks for pictures are
     much smaller than in Step 6 sent mail source.
  
Additional information
a) Possibly similar roots like 
b) I did not find a clear DUP in <https://bugzilla.mozilla.org/buglist.cgi?cmdtype=dorem&remaction=run&namedcmd=DUPs1235208&sharer_id=41036> 
c) Probably rather old bug, I will do tests where this started, soon.

Comment 1

[Rainer Bielefeld]

c): Already REPRODUCIBLE with EN-US SeaMonkey 2.10  Gecko/20100101, Classic Theme,
    on German WIN7 64bit 
d) All the same with Thunderbird 45.0a1 (2015-12-09)