Consider Not Restoring Tabs when Disabling PBO

[jhreis]

When a user turns on PBO on, we should prompt them that this will destroy all of their tabs (potentially other data?). This prevents a user who stays in PBO mode for many months from having super old tabs being restored. It can appear to be a security vulnerability.

Ref: #576

[jhreis]

Need final copy on what this user-message/confirmation should be.

[anthonypkeane]

Text for alert:

Enabling Private Browsing Only will close your current tabs

Cancel | Okay

@tomlowenthal can you pls confirm?

[tildelowengrimm]

Private Browsing Only mode will close all your current tabs and log you out of all sites.

[jhreis]

Do we have final product / security approval for this then @tomlowenthal and @anthonypkeane sounds like we do using the above copy?

[anthonypkeane]

The alert text is

Private Browsing Only mode will close all your current tabs and log you out of all sites.
Cancel | Okay

[jhreis]

Note to whoever picks this up. We then need to clear cookies to make sure users are also logged out of all of their sites.

[srirambv]

Verification passed on iPhone XR with iOS 13.2 running 1.14(19.11.27.14)

• Verified enabling PBO shows warn message
• Verified logged in session in a normal tab is lost when PBO is enabled
• Verified disabling PBO goes back to a normal tab and tabs from previous sessions are lost
• Verified browsing history is not lost when PBO is toggled
• Verified site shields settings are not lost when PBO is toggled

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Verification passed on iPhone 7+ with iOS 13.2 running 1.14(19.11.27.14)

• Verified enabling PBO shows warn message
• Verified logged in session in a normal tab is lost when PBO is enabled
• Verified disabling PBO goes back to a normal tab and tabs from previous sessions are lost
• Verified browsing history is not lost when PBO is toggled
• Verified site shields settings are not lost when PBO is toggled

---

Verification passed on iPhone 6 with iOS 12.4 running 1.14(19.11.27.14)

• Verified enabling PBO shows warn message
• Verified logged in session in a normal tab is lost when PBO is enabled
• Verified disabling PBO goes back to a normal tab and tabs from previous sessions are lost
• Verified browsing history is not lost when PBO is toggled
• Verified site shields settings are not lost when PBO is toggled

---

Verification passed on iPad Pro with iOS 13.2 running 1.14(19.11.27.14)

• Verified enabling PBO shows warn message
• Verified logged in session in a normal tab is lost when PBO is enabled
• Verified disabling PBO goes back to a normal tab and tabs from previous sessions are lost
• Verified browsing history is not lost when PBO is toggled
• Verified site shields settings are not lost when PBO is toggled

---

Verification passed on iPad Pro with iOS 12.4 running 1.14(19.11.27.14)

• Verified enabling PBO shows warn message
• Verified logged in session in a normal tab is lost when PBO is enabled
• Verified disabling PBO goes back to a normal tab and tabs from previous sessions are lost
• Verified browsing history is not lost when PBO is toggled
• Verified site shields settings are not lost when PBO is toggled