Allow to change the default Signal AppData location, since pasting or viewing images not working with server-sided userprofiles and folder redirection

[ITaluone]

• I have searched open and closed issues for duplicates

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Bug Description

This is a merge ticket for issue #5332, #5104, #5024! I apologize for this unnecessary confusion.

Reason is, that these three tickets problaby tells the same root cause.
(MS Windows server-sided userprofiles and folder redirection).

This leads in following errors:

• At pasting images: Warning: denying request to non-absolute path 'omain.local\dfs_shares\userdata\username\Anwendungsdaten\Signal[ Beta]\drafts.noindex
• At receiving images: Warning: denying request to non-absolute path 'omain.local\dfs_shares\userdata\username\Anwendungsdaten\Signal[ Beta]\attachments.noindex...

Note
The correct UNC path would be btw. \\domain.local\dfs_shares\userdata\username\Anwendungsdaten\Signal Beta\attachments.noindex.. . This should point out that \\d is omitted from the path.

The next curious thing is, that if you receive an image/video you could see that image/video preview while downloading, but after the download has finished the above error occurs and the image is not viewable. (pls see screenshots + screencast) to get this behaviour right.

A possible solution could be to move the signal appdata to %localappdata%\Signal if %appdata%\Signal is on an UNC path

Steps to Reproduce

1. Install Signal / Signal Beta on a Windows machine with a user who

• is in a Windows domain
• has server-sided userprofiles + folder redirection enabled (redirecting %appdata% to (in german) \\domain.local\dfs_shares\userdata\username\Anwendungsdaten\, and %localappdata% to C:\Users\username\AppData\Local

2. receive an image or video
3. while downloading see following => screencast 1
4. pasing an image/video see following => screencast 2

Actual Result:

See screencasts

Expected Result:

Images and videos are viewable in signal (without saving first).

Screenshots

Screencast 1:

Screencast 2:

Platform Info

Signal Version: 5.10.0 and 5.11.0-beta.1

Operating System:
Windows x64 20H2

Linked Device Version:
iOS: 14.7
Signal version: 5.16.1.3

Link to Debug Log

[DeathDragonAW]

I am affected of #5024 but I'm pretty sure I don't have a server-sided user profile since I use a local account on Win 10 Pro.

[ITaluone]

@scottnonnenberg-signal Sure this isn't primarily a bug?

[scottnonnenberg-signal]

We've previously made the decision to disallow access to network shares for security reasons. And you're asking for a new feature to work around that limitation.