1639597 - Persistent Private mode is not kept after Restart to update intervention is selected.

Status: NEW

(Firefox :: Address Bar, defect, P3)

Description

[Pablo]

Description
When in persistent private mode, if i use the update firefox intervention, it restarts to normal mode and not private.

Tested on

Windows10 64bit, MacOS 10.14, ubuntu 18.04 64bit (all affected)
Using FF nightly 78.0a1, FF release 76, FF beta 77.0b6 (all affected)

Steps to reproduce

1. Download an older version of firefox, example a version from last week
2. Create a new profile and set "use the selected profile without asking at startup" on profile manager.
3. Launch firefox with -private from command prompt and select the new profile
4. open a youtube video on a a tab, and wait some minutes for firefox to download the update.
5. type in megabar "update firefox" and click on "restart to update"
6. firefox is restarted, i see in history there is no youtube.
7. Now go to cnn.com and then close firefox.
8. Launch firefox again with -private
9. check /view history

Actual result:
You are on persistent private mode and you see cnn.com in history

Expected result
Cnn.com should not be in history, might be because after restart on step#5, it restarted to non-private mode.