Privacy Badger fails to unblock domains with DNT policy until after reload

[Hainish]

Related: EFForg/cover-your-tracks#49

When local learning is enabled, presence of the Do Not Track policy is not checked after a domain is initially added. In this example, no request is made to do-not-tracker.org:

After reloading the page, Privacy Badger unblocks do-not-tracker.org and allows the request to proceed:

[ghostwords]

Privacy Badger no longer checks DNT policies after first strike, rather only after fully learning to block the domain.

[ghostwords]

I wonder if we broke the DNT test with release 2020.5.12 that included the above PR.

Edit: We did.

[ghostwords]

If that's the case, the solution then is to either add a DNT preload list to Privacy Badger, or to update Panopticlick to retry once for the DNT test. I greatly prefer and ask that Panopticlick simply retry the test for now.

[Hainish]

I think it should be possible to ensure DNT is checked on the Panopticlick side before displaying the results.

[Hainish]

Fixed in EFForg/cover-your-tracks@2b2c491

[Hainish]

This still seems to be an issue when JavaScript is disabled, where I don't see Privacy Badger blocking any trackers.