Issue 6091 - Add checks for overly generic antiadblock filters

lib/antiadblockInit.js

Index: lib/antiadblockInit.js
===================================================================
--- a/lib/antiadblockInit.js
+++ b/lib/antiadblockInit.js
@@ -10,16 +10,18 @@
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/* globals publicSuffixes  */
+
 "use strict";
 
 const {Prefs} = require("prefs");
 const {ActiveFilter} = require("filterClasses");
 const {FilterStorage} = require("filterStorage");
 const {FilterNotifier} = require("filterNotifier");
 const {Subscription} = require("subscriptionClasses");
 const {Notification} = require("notification");
@@ -45,19 +47,24 @@
   {
     let urlFilters = [];
     for (let filter of subscription.filters)
     {
       if (filter instanceof ActiveFilter && filter.domains)
       {
         for (let [domain, included] of filter.domains)
         {
+          let domainIsTLD = !domain.includes(".") || domain.endsWith(".");

[kzar, 2018/05/25 13:51:56]

This logic doesn't look right to me, what about the example of
"dave.example.com.", that's definitely not a TLD.

[kzar, 2018/05/25 13:51:57]

This variable seems kind of pointless, when we only use it once and immediately
after we declare it.

[Jon Sonesen, 2018/05/25 21:04:39]

Hm, but there is the case where `com.` and `com` should be treated equally,
meaning it is considered a TLD. However in all other cases it isn't considered a
TLD? I am confused about what you guys want here. If it doesn't have a dot it's
generic but if it ends with a dot it isn't and yet "com" and "com." are treated
the same? This is seems contradictory  can you please clarify?

+          if (domainIsTLD || publicSuffixes.hasOwnProperty(domain))

[kzar, 2018/05/25 13:51:57]

If the domain ends in "." it won't be found in publicSuffixes, for example
"googlecode.com.".

[Jon Sonesen, 2018/05/25 21:04:39]

Acknowledged.

+            continue;
           let urlFilter = "||" + domain + "^$document";
           if (domain && included && urlFilters.indexOf(urlFilter) == -1)

[kzar, 2018/05/25 13:51:57]

It seems a shame we're doing these cheaper checks `domain && included` after
some more expensive ones like `domain.endsWith(".")`.

[Jon Sonesen, 2018/05/25 21:04:39]

Acknowledged.

+          {
             urlFilters.push(urlFilter);
+          }
         }
       }
     }
     notification.urlFilters = urlFilters;
     Notification.addNotification(notification);
     Notification.addQuestionListener(notification.id, notificationListener);
   }