Issue 4978 - Avoid custom filters from being displayed multiple times

options.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 74 matching lines @@
    ["synchronize_connection_error",
     "filters_subscription_lastDownload_connectionError"],
    ["synchronize_invalid_data",
     "filters_subscription_lastDownload_invalidData"],
    ["synchronize_checksum_mismatch",
     "filters_subscription_lastDownload_checksumMismatch"]
 ]);
 
 let delayedSubscriptionSelection = null;
 let acceptableAdsUrl;
+let specialSubscriptionBeingAdded = null;
 
 // Loads options from localStorage and sets UI elements accordingly
 function loadOptions()
 {
   // Set page title to i18n version of "Adblock Plus Options"
   document.title = i18n.getMessage("options");
 
   // Set links
   getPref("subscriptions_exceptionsurl", url =>
   {
@@ skipping 81 matching lines @@
   // Load recommended subscriptions
   loadRecommendations();
 
   // Show user's filters
   reloadFilters();
 }
 $(loadOptions);
 
 function convertSpecialSubscription(subscription)
 {
+  specialSubscriptionBeingAdded = subscription.url;
   getFilters(subscription.url, filters =>
   {
     for (let filter of filters)
     {
       if (whitelistedDomainRegexp.test(filter.text))
         appendToListBox("excludedDomainsBox", RegExp.$1);
       else
         appendToListBox("userFiltersBox", filter.text);
     }
+    specialSubscriptionBeingAdded = null;
   });
 }
 
 // Reloads the displayed subscriptions and filters
 function reloadFilters()
 {
   // Load user filter URLs
   let container = document.getElementById("filterLists");
   while (container.lastChild)
     container.removeChild(container.lastChild);
@@ skipping 281 matching lines @@
     case "notifications_ignoredcategories":
       key = "shouldShowNotifications";
       value = value.indexOf("*") == -1;
       break;
   }
   let checkbox = document.getElementById(key);
   if (checkbox)
     checkbox.checked = value;
 }
 
-function onFilterMessage(action, filter)
+function onFilterMessage(action, filter, subscription)
 {
+  // When the user adds a custom filter for the first time a special
+  // subscription is created automatically. When the happens we'll receive a
+  // message for the subscription first, then the filter. To avoid displaying
+  // the filter twice we have to be careful to ignore filter messages for a
+  // newly added subscription which we're still in the process of handling.
+  if (specialSubscriptionBeingAdded && subscription &&
+      subscription.url == specialSubscriptionBeingAdded)
+  {
+    return;
+  }
+
   switch (action)
   {
     case "loaded":
       reloadFilters();
       break;
     case "added":
       if (whitelistedDomainRegexp.test(filter.text))
         appendToListBox("excludedDomainsBox", RegExp.$1);
       else
         appendToListBox("userFiltersBox", filter.text);
@@ skipping 209 matching lines @@
               previous[0].classList.remove("focused");
 
             let index = $("[href='#" + tab.id + "']").parent().index();
             $("#tabs").tabs("select", index);
             found.classList.add("focused");
           }
           break;
       }
       break;
     case "filters.respond":
-      onFilterMessage(message.action, message.args[0]);
+      onFilterMessage(message.action, message.args[0], message.args[1]);
       break;
     case "prefs.respond":
       onPrefMessage(message.action, message.args[0]);
       break;
     case "subscriptions.respond":
       onSubscriptionMessage(message.action, message.args[0]);
       break;
   }
 });