Issue 6783 - opt-in to anti circumvention filter list on upgrade

lib/subscriptionInit.js

Index: lib/subscriptionInit.js
===================================================================
--- a/lib/subscriptionInit.js
+++ b/lib/subscriptionInit.js
@@ -53,28 +53,28 @@
 
   if (firstRun && (!FilterStorage.firstRun || Prefs.currentVersion))
     reinitialized = true;
 
   Prefs.currentVersion = info.addonVersion;
 }
 
 /**
- * Determines whether to add the default ad blocking subscription.
+ * Determines whether to add the default ad blocking subscriptions.
  * Returns true, if there are no filter subscriptions besides those
  * other subscriptions added automatically, and no custom filters.
  *
  * On first run, this logic should always result in true since there
  * is no data and therefore no subscriptions. But it also causes the
- * default ad blocking subscription to be added again after some
+ * default ad blocking subscriptions to be added again after some
  * data corruption or misconfiguration.
  *
  * @return {boolean}
  */
-function shouldAddDefaultSubscription()
+function shouldAddDefaultSubscriptions()
 {
   for (let subscription of FilterStorage.subscriptions)
   {
     if (subscription instanceof DownloadableSubscription &&
         subscription.url != Prefs.subscriptions_exceptionsurl &&
         subscription.url != Prefs.subscriptions_antiadblockurl)
       return false;
 
@@ -205,18 +205,19 @@
       let antiAdblockSubscription = Subscription.fromURL(
         Prefs.subscriptions_antiadblockurl
       );
       antiAdblockSubscription.disabled = true;
       subscriptions.push(antiAdblockSubscription);
     }
   }
 
-  // Add default ad blocking subscription (e.g. EasyList)
-  if (shouldAddDefaultSubscription())
+  // Add default ad blocking subscriptions (e.g. EasyList, Anti-Circumvention)
+  let addDefaultSubscription = shouldAddDefaultSubscriptions();
+  if (addDefaultSubscription || !Prefs.subscriptions_addedanticv)
   {
     return fetch("subscriptions.xml")
       .then(response => response.text())
       .then(text =>
       {
         let doc = new DOMParser().parseFromString(text, "application/xml");
         let nodes = doc.getElementsByTagName("subscription");
 
@@ -227,22 +228,30 @@
           {
             let node = defaultSubscriptions[name];
             if (!node)
               continue;
 
             let url = node.getAttribute("url");
             if (url)
             {
+              // Make sure that we don't add Easylist again if we want
+              // to just add the Anti-Circumvention subscription.
+              let type = node.getAttribute("type");
+              if (!addDefaultSubscription && type != "circumvention")
+                continue;
+
               let subscription = Subscription.fromURL(url);
               subscription.disabled = false;
               subscription.title = node.getAttribute("title");
               subscription.homepage = node.getAttribute("homepage");
-              subscription.type = node.getAttribute("type");
+              subscription.type = type;
               subscriptions.push(subscription);
+              if (subscription.type == "circumvention")
+                Prefs.subscriptions_addedanticv = true;
             }
           }
         }
 
         return subscriptions;
       });
   }