536737 - The "Download Manager Window" pops up when opening an e-mail attachment although the attachment has already been localized (i. e. downloaded for IMAP offline use)

Status: UNCONFIRMED

(Thunderbird :: Mail Window Front End, enhancement)

Description

[dfghjkjhg]

User-Agent:       
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.0; de; rv:1.9.1.5) Gecko/20091204 Lightning/1.0b2pre Thunderbird/3.0

I made all mails in all IMAP folders available for immediate offline use:
mail.check_all_imap_folders_for_new --> true
mail.imap.use_status_for_biff --> false
mail.server.default.autosync_offline_stores --> true

This means that all mails and their attachments are already localized on my computer.

Nevertheless when I open such an attachment the "Download Manager Window" pops up. But in fact it's not a download ! I just open a local file.
Therefore in this case the "Download Manager Window" should not appear.	

Reproducible: Always

Comment 1

[Frank von Delft]

It does seem to download it for real, every time (I notice this on slow connections, I have the same settings).  

In fact, TB's behaviour of IMAP attachments are a complete disaster whenever I'm on slow connections (e.g. travelling, which happens often).  What I'd expect (for the settings above) is this:

1) When message first appears, download only the body (all of it), but NOT the attachment;  only show its file-size.

2) Download the attachment ONLY when I explicitly ask for it (and allow me to cancel the download).  Leave it in the cache.

3) For ever after, when I open the attachment, ALWAYS get it from the cache, unless I explicitly ask for it (e.g. give me a "re-cache" option on the right-click menu).