1663547 - Disabling Containers Feature closes all container tabs unexpectedly

Status: RESOLVED DUPLICATE of bug 1549204

(Core :: Security, defect)

Description

[JulianHofstadter]

When turning off Containers feature whether:

1. Feature was activated by enabling the Tabs/Containers UI in Preferences using about:config settings:

privacy.userContext.enabled
privacy.userContext.ui.enabled
privacy.userContext.longPressBehavior

If disabling the feature in the Preferences Tabs/Containers UI, I have observed 2 things happen:

Either all container tabs are immediately closed, and then a prompt is displayed with a warning that tabs will be closed (after it's too late) or,

A prompt is displayed warning the user that disabling will close all container tabs. However, even when clicking "keep enabled", the feature is disabled anyway, and all container tabs are closed anyway.

2. Feature was activated using the Firefox Multi-account Containers addon:
   https://addons.mozilla.org/en-US/firefox/addon/multi-account-containers/

If the addon is disabled or removed, all container tabs are closed without warning. This is even true if it is disabled using the Preferences Containers UI. In this case there is not prompt at all.

Moreover, the tabs which are removed do not appear in the closed tabs history.

Very serious bug IMO.

I do not know if this should be broken into 2 bugs, one for the internal UI, one for the addon case. Please advise.

Steps to repeat:

First case:

1. Create new profile

2. Open in Firefox

3. Set the following prefs in about:config: (based on instructions from
   https://support.mozilla.org/en-US/kb/containers)

privacy.userContext.enabled: true
privacy.userContext.ui.enabled: true
privacy.userContext.longPressBehavior: 2

4. Open new container tab: File > New Container Tab > Personal

5. Go to tab, open web page within

6. In Preferences > Tabs, un-check "Enable Container Tabs"

7. Observe that, either the container tab is immediately closed, OR, Observe prompt warning that the container tab will be closed, also giving the option to "Keep enabled", or "Close 1 container tab"

8. Click "Keep enabled"

9. Observe Container tabs are disabled, and the container tab is closed.

10. Go to History > Recently Closed Tabs, observe the closed container tab is not listed.

Second case, using addon:

1. Create new profile

2. Open in Firefox

3. Install the following addon:
   https://addons.mozilla.org/en-US/firefox/addon/multi-account-containers/

4. Open new container tab: File > New Container Tab > Personal

5. Go to tab, open web page within

6. In Preferences > Tabs, see that a message is given saying "An extension, Firefox Multi-account Containers, requires container tabs"

7. Click the "Disable Extension" button

8. Observe that the container tab is closed

9. Go to History > Recently Closed Tabs, observe the closed container tab is not listed.

Comment 1

[JulianHofstadter]

Another nefarious side-effect of this is:

1. User enables container tabs through the Preferences > Tabs > Container tabs UI

2. Creates a bunch of container tabs

3. Installs an addon requiring contextualIdentities permission that may just be to offer enhancement the Containers feature

4. Disables or uninstalls the addon for any reason

5. All container tabs will be removed, including those created before the addon was installed.

Comment 2

[JulianHofstadter]

(In reply to JulianHofstadter from comment #1)

Another nefarious side-effect of this is:

1. User enables container tabs through the Preferences > Tabs > Container tabs UI

2. Creates a bunch of container tabs

3. Installs an addon requiring contextualIdentities permission that may just be to offer enhancement the Containers feature

4. Disables or uninstalls the addon for any reason

5. All container tabs will be removed, including those created before the addon was installed.

Actually, this appears to be intermittent. AFACT however, the behavior in the original description is consistent.

Comment 3

[Clara Guerrero ( Need Info Brindusa Tot Please)]

Hi,

I'm testing this on windows 10 pro, release 80.0, beta 81.0, and nightly 82.0a1 (2020-09-15)

I was able to reproduce second case but not the first one.
In the first case, after step 8, Container tabs is not disabled when pressing "keep enabled" so it's correct it's not displayed under recently closed tabs as it hasn't closed
In the second case, after reaching step 7, the container tab is closed and it won't appear listed in recently closed tabs

I will move this over to a component so developers can take a look over it. If is not the correct component please feel free to change it to an appropriate one.

Thanks for the report.

Best regards, Clara.

Comment 4

[Daniel Veditz [:dveditz]]

Using the hidden prefs is an unsupported configuration, all the testing is focused on the use of the add-on. The prefs turn on the same basic internals, but as bugs and conflicts are found they tend to get fixed in the add-on code and not in the core code. In particular the add-on has more refined clean-up code.

Issues in the add-on are tracked at https://github.com/mozilla/multi-account-containers/issues
This might be the same as https://github.com/mozilla/multi-account-containers/issues/1236 but if not you'll have better luck filing it there.

Comment 5

[Johann Hofmann [:johannh]]

I think this is more of a dupe of bug 1549204 :)