Heads up: no-ads is broken by Firefox 51

[John LoVerso]

A security change in as a result of this report breaks no-ads.  This is released in Firefox 51 and latest releases of Chrome.  The Firefox bug report for the change is https://bugzilla.mozilla.org/show_bug.cgi?id=1255474.

To get this to work in again, you need to set a preference.
In Chrome: PacHttpsUrlStrippingEnabled to false
In Firefox: network.proxy.autoconfig_url.include_path to true

However, as of this writing, I just found that Firefox does not seem to be obeying this preference (51.0.1 on Windows, 32bit).  No matter if it is true or false, the URL passed to FindProxyForURL() contains to lack the path.  I've reported this in the Firefox bug thread.

What this means is that blocking based upon path no longer works.  Blocking based upon hostname continues to work.

[John LoVerso]

The Chrome bug thread is here: https://bugs.chromium.org/p/chromium/issues/detail?id=593759

[John LoVerso]

The preference setting will be fixed in Firefox 52:

https://bugzilla.mozilla.org/show_bug.cgi?id=1336069

[John LoVerso]

I'm now running the 52.0 release and it does indeed work again.

[Dan Grillo]

Hi John, it looks like recent 10.11 releases of Mac OS X (I'm on 10.11.6 right now) stop Safari from working with no-ads.   I've been using it for years.   Any suggestions?

Thanks,

Dan

[James Lewis]

The policy in question was added in Chrome 52, along with the command-line flag --unsafe-pac-url; the policy was originally defaulted to false for enterprise users and true otherwise, and then it was defaulted to true even for enterprise users in Chrome 71, before being removed entirely in Chrome 74 (with the command-line flag removed in Chrome 75): https://bugs.chromium.org/p/chromium/issues/detail?id=619087#c24

The relevant docs mention that path-stripping may also be extended to non-HTTPS URLs in the future: https://bugs.chromium.org/p/chromium/issues/detail?id=882536