Issue 5042 - Adds handling for requests which are not associated with browser tab

lib/requestBlocker.js

Index: lib/requestBlocker.js
===================================================================
--- a/lib/requestBlocker.js
+++ b/lib/requestBlocker.js
@@ -20,17 +20,18 @@
 "use strict";
 
 const {Filter, RegExpFilter, BlockingFilter} = require("filterClasses");
 const {Subscription} = require("subscriptionClasses");
 const {defaultMatcher} = require("matcher");
 const {FilterNotifier} = require("filterNotifier");
 const {Prefs} = require("prefs");
 const {checkWhitelisted, getKey} = require("whitelisting");
-const {stringifyURL, extractHostFromFrame, isThirdParty} = require("url");
+const {stringifyURL, getDecodedHostname,
+      extractHostFromFrame, isThirdParty} = require("url");
 const {port} = require("messaging");
 const devtools = require("devtools");
 
 // Chrome can't distinguish between OBJECT_SUBREQUEST and OBJECT requests.
 RegExpFilter.typeMap.OBJECT_SUBREQUEST = RegExpFilter.typeMap.OBJECT;
 
 function onBeforeRequestAsync(page, url, type, docDomain,
                               thirdParty, sitekey,
@@ -46,23 +47,28 @@
       thirdParty, sitekey,
       specificOnly, filter
     );
   }
 }
 
 ext.webRequest.onBeforeRequest.addListener((url, type, page, frame) =>
 {
-  if (checkWhitelisted(page, frame))
-    return true;
+  let docDomain = getDecodedHostname(url);

[Sebastian Noack, 2017/04/21 08:39:53]

Is there a reason you derive the parent document's domain from the request URL?
Note that these makes requests that don't have an associated tab
indistinguishable from those that that have (in the devtools panel). Also it
seems incorrect, as *$domain=example.com is supposed to match subrequests from
documents served from example.com, not requests that are served from example.com
in documents served from other domains.

[Jon Sonesen, 2017/04/24 08:40:56]

I see, I misunderstood what I was doing here. I just saw that the docDomain was
being defined before but was not sure how to fetch it without the page variable
and saw that the docDomain can also be obtained via the getDecodedHostname
function. So what is the best option here? Should I just set the domain as the
URL?

+  let sitekey = null;
+  if (frame && page)
+  {
+    if (checkWhitelisted(page, frame))
+      return true;
+    docDomain = extractHostFromFrame(frame);
+    sitekey = getKey(page, frame);
+  }
 
   let urlString = stringifyURL(url);
-  let docDomain = extractHostFromFrame(frame);
   let thirdParty = isThirdParty(url, docDomain);
-  let sitekey = getKey(page, frame);
 
   let specificOnly = !!checkWhitelisted(
     page, frame, RegExpFilter.typeMap.GENERICBLOCK
   );
 
   let filter = defaultMatcher.matchesAny(
     urlString, RegExpFilter.typeMap[type],
     docDomain, thirdParty, sitekey, specificOnly