Bug 75008

Summary:	navigator.doNotTrack returns wrong values.
Product:	WebKit	Reporter:	Justin Lebar <justin.lebar+bug>
Component:	DOM	Assignee:	Nobody <webkit-unassigned>
Status:	RESOLVED INVALID
Severity:	Normal	CC:	ap, me
Priority:	P2	Keywords:	InRadar
Version:	528+ (Nightly build)
Hardware:	Unspecified
OS:	Unspecified

Description Justin Lebar 2011-12-21 08:07:25 PST

We decided that navigator.doNotTrack would return "yes/no/unspecified" in Firefox, but Safari 5.1 apparently [1] returns "1/0/(empty string)" to match the DNT header.

The reason we did "yes/no/unspecified" is because we wanted no value to parse as "false" in JS.  This way, buggy code which does |if (navigator.doNotTack)| will fail closed.  With 1/0/(unspecified), the bogus boolean check works so long as you never have people explicitly opting in to DNT; thus we were afraid that sites would rely on DNT being a boolean, rather than a tri-state, and then we'd never be able to send navigator.doNotTrack == "0".

How would you feel about changing to match Firefox's implementation?

[1] https://bugzilla.mozilla.org/show_bug.cgi?id=712616

Comment 1 Justin Lebar 2011-12-21 11:00:20 PST

> With 1/0/(unspecified), the bogus boolean check works

Er, that should be "With 1/0/(empty string)".

Comment 2 Alexey Proskuryakov 2011-12-21 15:56:14 PST

<rdar://problem/10616671>

Comment 3 Alexey Proskuryakov 2011-12-21 15:59:58 PST

Perhaps confusingly, WebKit doesn't implement the doNotTrack property yet. Adding it is tracked by bug 73088.

In Safari, doNotTrack property is injected by closed source browser code. I have migrated your report to Apple's internal system, and will close this bug now as a non-WebKit issue. Thank you very much for letting us know!