1964145 - TB cannot access (old) detached attachments on UNC drive

Status: RESOLVED FIXED

(Thunderbird :: General, defect)

Description

[Dominik Schultheiß]

Attachment: 2025-04-28 - Screenshot Detached Attachments.png

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Steps to reproduce:

I have been separating larger attachments to a network storage location (SMB share in Windows network without domain) for years.
This has worked for years across different Thunderbird versions without any problems. The attachments could be detached without any problems and were also found again.
I switched from the esr-channel (128. ...) to the release-channel (137. ... / 138. ...). Since then, detached attachments are no longer found.

Actual results:

Since switching from the esr-channel (128. ...) to the release-channel (137. ... / 138. ...) detached attachments are no longer found.
This applies both to attachments that were detached years ago with earlier versions and to attachments that have just been detached with the current TB version.
The path is of course available. The detachment is carried out without an error message. The detached attachments are then actually located there. It also works to right-click on the detached file and select “Copy link address”.
However, the detached attachments are crossed out and can no longer be opened from Thunderbird itself.

Expected results:

The detached attachments should be found by Thunderbird instead of being crossed out, as was the case up to and including version 128. ... (esr).

Comment 1

[Dominik Schultheiß]

The problem is identical on every computer that has been updated from the 128. ... ESR to the current 137. ... / 138. ... release.
None of these 137. ... / 138. ... Thunderbird releases can find any detached attachment.

Comment 2

[Magnus Melin [:mkmelin]]

Looks like an UNC file:// path.

Due to security/privacy concerns there we had to apply some restrictions, so UNC paths are no longer directly allowed.
Use a mapped drive instead.

Comment 3

[Dominik Schultheiß]

Yes, it is indeed a UNC path.
In the future, I can use a path on a mapped network drive for newly detached attachments.

However, how can I re-link the attachments that have already been detached and linked to the UNC path?
The fact that the attachments are now simply gone is not a solution.

Comment 4

[Magnus Melin [:mkmelin]]

Attachment: Bug 1964145 - Allow access to attachments at specific UNC hosts. r=#thunderbird-reviewers

Comment 5

[Dominik Schultheiß]

Thanks, that looks good and gives me hope.
At the moment I'm using an add-on that replaces part of the UNC path with the drive letter of a mapped drive.
Once it is implemented, I will add the server name “NAS” as an exception in the mail.allowed_attachment_hostnames setting.

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/1807d010353b
Allow access to attachments at specific UNC hosts. r=arschmitz

Comment 7

[Francesco]

Looks like an unintended hunk got added: https://hg-edge.mozilla.org/comm-central/rev/1807d010353b#l2.12

Comment 8

[Magnus Melin [:mkmelin]]

Yep sorry about that.
Unintended part removed here: https://hg.mozilla.org/comm-central/rev/6046d7c0bc6ed7282b7ed50b98de1f6c7c8893d4

Comment 9

[Corey Bryant]

Magnus, do you want to uplift this to beta?

Comment 10

[Magnus Melin [:mkmelin]]

Comment on attachment 9485544 [details]
Bug 1964145 - Allow access to attachments at specific UNC hosts. r=#thunderbird-reviewers

Uplift Approval Request

• Please state case for uplift consideration and ensure bug severity is set: Regression
• User impact if declined: Users using UNC paths for atachments could not access detached attachments.
• Is this code covered by automated tests?: No
• Has the fix been verified in Daily?: Yes
• Has the fix been verified in Beta?: No
• Needs manual test from QA?: No
• If yes, steps to reproduce:
• List of other uplifts needed: None
• Risk to taking this patch: Low
• Why is the change risky/not risky? (and alternatives if risky): Contained fix
• String changes made/needed: none

Comment 11

[Corey Bryant]

Comment on attachment 9485544 [details]
Bug 1964145 - Allow access to attachments at specific UNC hosts. r=#thunderbird-reviewers

[Triage Comment]
Approved for beta

Comment 12

[Daniel Darnell [:dandarnell]]

Thunderbird 139.0b3:
https://hg.mozilla.org/releases/comm-beta/rev/65cd8f326ce9

Comment 13

[Magnus Melin [:mkmelin]]

Please also uplift https://hg.mozilla.org/comm-central/rev/6046d7c0bc6ed7282b7ed50b98de1f6c7c8893d4