286454 - Opening a "deleted attachment" notice should not be opened in the original attachment's associated application

Status: RESOLVED DUPLICATE of bug 476400

(MailNews Core :: Attachments, defect)

Description

[Mike Cowperthwaite]

Shortcoming with bug 2920's patch.  TB 1.0+0316, Windows 2000.
To some degree, this is primarily a problem under Windows.

When a message has had its attachment stripped, the attachment panel shows the 
notice of detachment as yet another attachment.  This attachment has been given
  Content-Type: text/x-moz-deleted; name="Deleted:oldname.ext"

By default, there is no handler in place for the MIME type text/x-moz-deleted.
In this case, Thunderbird searches for a handler based on the attachment's 
extension.  (This seems wrong; xref bug 277046.)

What happens next depends on whether the original attachment had a handler 
defined for the particular extension, and if not, whether there is a system-
defined handler accessible to TB.  Suppose the attachment was a JPG.

 - If TB knows that JPG is handled by the system image editor, that program will 
be started -- and, typically, throw an error about the illegal attachment.  
 - If TB doesn't know about JPG, it will show the "What should TB do with this 
file?" prompt.  In Windows, it will say the file is an image -- the user may 
choose to open it or save, and may choose to have that option set as the 
default.  If he chooses to open it by default in the image editor, opening the 
attachment will fail; if he knows it supposed to be text, and picks a text 
editor for display, opening will succeed.

In both of these latter cases, if the user *also* says "Do this automatically 
... from now on", mimeTypes.rdf will be updated with entries associating JPG 
with text/x-moz-deleted.  Thereafter, whichever application was chosen will 
always be used to open further text/x-moz-deleted attachments, possibly meaning 
more error messages each time until the attachment association is fixed.

Furthermore, in Thunderbird, it will be listed in the Download Actions under 
"JPG" which may cause quite a bit of confusion.  (Note that, separate from this 
bug, the Change Action dialog is completely broken in the current trunk build as 
well.)  I copied a message with a deleted attachment into my Seamonkey mail, and 
it installs the default action in the same way, but allows editing of that 
action, and also (CORRECTLY) lists the item by the MIME type rather than the 
extension.


The best way to avoid this problem is to provide a default handler for 
text/x-moz-deleted in mimeTypes.rdf; ideally, it would be added to existing 
profiles, if nonexistent.

One way to sidestep the mis-association with an unrelated application would be 
to also rename the file differently: instead of
 "Deleted:oldname.ext"
use
 "oldname.ext.deleted"
which would create an entry for the ".deleted" extension.  This would also be 
easier to manage within the extension-based TB Download Actions listing.

Comment 1

[Serge Gautherie (:sgautherie)]

[Mozilla/5.0 (Windows; U; Win98; en-US; rv:1.8b2) Gecko/20050520] (nightly) (W98SE)

Confirming: MAS too.

Comment 2

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

sorry for the spam.  making bugzilla reflect reality as I'm not working on these bugs.  filter on FOOBARCHEESE to remove these in bulk.

Comment 3

[Magnus Melin [:mkmelin]]

Disabling opening deleted attachment in bug 476400.