Issue 6108 - No filter list is selected after a migration failure

adblockplus/Api.jsm

Index: adblockplus/Api.jsm
===================================================================
--- a/adblockplus/Api.jsm
+++ b/adblockplus/Api.jsm
@@ -40,39 +40,53 @@ let {Filter, RegExpFilter} = require("fi
 let {FilterNotifier} = require("filterNotifier");
 let {FilterStorage} = require("filterStorage");
 let {defaultMatcher} = require("matcher");
 let {Prefs} = require("prefs");
 let {Subscription, SpecialSubscription, RegularSubscription, DownloadableSubscription, ExternalSubscription} = require("subscriptionClasses");
 let {Synchronizer} = require("synchronizer");
 let {UI} = require("ui");
 
-let subscriptionsSavedPref = "subscriptions_saved";
+const SUBSCRIPTIONS_SAVED_PREF = "subscriptions_saved";
+const USER_REMOVED_BLOCK_SUBS_PREF = "user_removed_block_subscriptions";
+const USER_REMOVED_EXCEPTIONS_SUB_PREF = "user_removed_exception_subscription";
 
 function initFilterListeners()
 {
   FilterNotifier.on("load", onFiltersLoad);
   FilterNotifier.on("save", onFiltersSave);
 }
 
 function onFiltersLoad()
 {
+  let detectedSubscriptionFailure = !hasBlockSubscription() &&
+    (!getBoolPref(SUBSCRIPTIONS_SAVED_PREF) || !getBoolPref(USER_REMOVED_BLOCK_SUBS_PREF) || FilterStorage.loadFromDiskFailed);
+
+  // We will only try to recover the default subscription settings if the addonVersion hasn't changed,
+  // otherwise it will be handled in firstRunActions(), inside ui.js
   let {addonVersion} = require("info");
-  if (Prefs.currentVersion == addonVersion && !getBoolPref(subscriptionsSavedPref))
+  if (Prefs.currentVersion == addonVersion && detectedSubscriptionFailure)
   {
-    UI.addSubscription(UI.currentWindow, Prefs.currentVersion);
+    if (getBoolPref(USER_REMOVED_EXCEPTIONS_SUB_PREF))
+    {
+      UI.addSubscription(UI.currentWindow, Prefs.currentVersion);
+    }
+    else
+    {
+      UI.addSubscription(UI.currentWindow, "0.0");
+    }
   }
   Messaging.sendRequest({ type: "Abb:OnFiltersLoad" });
 }
 
 function onFiltersSave()
 {
-  if (FilterStorage.subscriptions.some((subscription) => subscription instanceof DownloadableSubscription && subscription.url != Prefs.subscriptions_exceptionsurl))
+  if (hasBlockSubscription())
   {
-    setBoolPref(subscriptionsSavedPref, true);
+    setBoolPref(SUBSCRIPTIONS_SAVED_PREF, true);
   }
   Messaging.sendRequest({ type: "Abb:OnFiltersSave" });
 }
 
 function getBoolPref(name)
 {
   let branch = getPrefsBranch();
   try
@@ -94,16 +108,22 @@ function setBoolPref(name, value)
 
 function getPrefsBranch()
 {
   let {addonRoot, addonName} = require("info");
   let branchName = "extensions." + addonName + ".";
   return Services.prefs.getBranch(branchName);
 }
 
+function hasBlockSubscription()
+{
+  return FilterStorage.subscriptions.some(
+    subscription => subscription instanceof DownloadableSubscription && subscription.url != Prefs.subscriptions_exceptionsurl);
+}
+
 function getWhitelistingFilter(url)
 {
   let uriObject = Services.io.newURI(url, null, null);
   try
   {
     return defaultMatcher.whitelist.matchesAny(
       uriObject.spec, RegExpFilter.typeMap.DOCUMENT, uriObject.host, false, null, false);
   }
@@ -164,21 +184,36 @@ var AdblockPlusApi =
     if (subscription)
     {
       subscription.disabled = false;
       if (!subscription.lastDownload)
       {
         Synchronizer.execute(subscription);
       }
     }
+    if (url == Prefs.subscriptions_exceptionsurl)
+    {
+      setBoolPref(USER_REMOVED_EXCEPTIONS_SUB_PREF, false);
+    }
+    else if (hasBlockSubscription())
+    {
+      setBoolPref(USER_REMOVED_BLOCK_SUBS_PREF, false);
+    }
   },
   removeSubscription: function(url)
   {
-    FilterStorage.removeSubscription(
-      FilterStorage.knownSubscriptions[url]);
+    FilterStorage.removeSubscription(FilterStorage.knownSubscriptions[url]);
+    if (url == Prefs.subscriptions_exceptionsurl)
+    {
+      setBoolPref(USER_REMOVED_EXCEPTIONS_SUB_PREF, true);
+    }
+    else if (!hasBlockSubscription())
+    {
+      setBoolPref(USER_REMOVED_BLOCK_SUBS_PREF, true);
+    }
   },
   getActiveSubscriptions: function()
   {
     let subscriptions = [];
     for (let i = 0; i < FilterStorage.subscriptions.length; i++)
     {
       let subscription = FilterStorage.subscriptions[i];
       if (!subscription.disabled)