1469500 - Integrity of "Clear Recent History"

Status: NEW

(Toolkit :: Data Sanitization, enhancement, P3)

Description

[Anne (:annevk)]

At the most recent San Francisco All Hands we discussed how "Clear Recent History" can leave sites in an inconsistent state. (Clearing storage at a level that is more granular than an origin will lead to issues, effectively.)

Another problem is that if you visit media.example on a daily basis you probably did not mean for its storage to be wiped, but only shop.example.

Comment 1

[Johann Hofmann [:johannh]]

This is less about preferences and more a fundamental question about any type of data clearing, should we clear data that was set in a time range or should we clear all data from sites that have been active in the specified range.

FWIW I think for quota storage we do the latter, for cookies the former, right?

In real life I don't think this is an important question, tbh.

Comment 2

[Martin Thomson [:mt:]]

In real life?  The key question is about the integrity of the information we retain for an origin.  If we start puncturing random pieces of it, then the state could violate invariants that the site relies on.  That leads to sites being broken in Firefox.

As we discussed, the proposed change is to forget sites that were newly visited in the specified period.

If we were able to rewind state to any point in time, that would be even better, but that seems hard.  At least we should not pretend that we can remove recent history when all we can do is damage it.

Do we have telemetry on the use of this feature that suggests it is widely and frequently used, such that we might be convinced that the damage we're doing isn't causing obvious harm?