Issue 3761 - Don't clear user input when filter validation failed

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 499 matching lines @@
     while (element)
     {
       if (element.hasAttribute("data-" + dataName))
         return returnElement ? element : element.getAttribute("data-" + dataName);
 
       element = element.parentElement;
     }
     return null;
   }
 
+  function sendMessageHandleErrors(message, onSuccess)
+  {
+    ext.backgroundPage.sendMessage(message, function(errors)
+    {
+      if (errors.length > 0)
+        alert(errors.join("\n"));
+      else if (onSuccess)
+        onSuccess();
+    });
+  }
+
   function onClick(e)
   {
     var context = document.querySelector(".show-context-menu");
     if (context)
       context.classList.remove("show-context-menu");
 
     var element = e.target;
     while (true)
     {
       if (!element)
@@ skipping 40 matching lines @@
           break;
         case "import-subscription":
           var url = E("blockingList-textbox").value;
           addEnableSubscription(url);
           closeDialog();
           break;
         case "open-dialog":
           openDialog(element.getAttribute("data-dialog"));
           break;
         case "save-custom-filters":
-          ext.backgroundPage.sendMessage(
+          sendMessageHandleErrors(
           {
             type: "filters.importRaw",
             text: E("custom-filters-raw").value
+          },
+          function()
+          {
+            E("custom-filters").classList.remove("mode-edit");
           });
-          E("custom-filters").classList.remove("mode-edit");
           break;
         case "switch-tab":
           document.body.setAttribute("data-tab",
             element.getAttribute("data-tab"));
           break;
         case "update-all-subscriptions":
           ext.backgroundPage.sendMessage(
           {
             type: "subscriptions.update"
           });
@@ skipping 79 matching lines @@
         addWhitelistedDomain();
     }, false);
 
     // Advanced tab
     var filterTextbox = document.querySelector("#custom-filters-add input");
     placeholderValue = getMessage("options_customFilters_textbox_placeholder");
     filterTextbox.setAttribute("placeholder", placeholderValue);
     function addCustomFilters()
     {
       var filterText = filterTextbox.value;
-      ext.backgroundPage.sendMessage(
+      sendMessageHandleErrors(
       {
         type: "filters.add",
         text: filterText
+      },
+      function()
+      {
+        filterTextbox.value = "";
       });
-      filterTextbox.value = "";
     }
     E("custom-filters-add").addEventListener("submit", function(e)
     {
       e.preventDefault();
       addCustomFilters();
     }, false);
     var customFilterEditButtons = document.querySelectorAll("#custom-filters-edit-wrapper button");
 
     E("dialog").addEventListener("keydown", function(e)
     {
@@ skipping 99 matching lines @@
           onSubscriptionMessage("added", subscriptions[i]);
       });
     });
   }
 
   function addWhitelistedDomain()
   {
     var domain = E("whitelisting-textbox");
     if (domain.value)
     {
-      ext.backgroundPage.sendMessage(
+      sendMessageHandleErrors(
       {
         type: "filters.add",
         text: "@@||" + domain.value.toLowerCase() + "^$document"
       });
     }
 
     domain.value = "";
     document.querySelector("#whitelisting .controls").classList.remove("mode-edit");
   }
 
@@ skipping 165 matching lines @@
     {
       case "app.listen":
         if (message.action == "addSubscription")
         {
           var subscription = message.args[0];
           var dialog = E("dialog-content-predefined");
           dialog.querySelector("h3").textContent = subscription.title || "";
           dialog.querySelector(".url").textContent = subscription.url;
           openDialog("predefined");
         }
-        else if (message.action == "error")
-        {
-          alert(message.args.join("\n"));
-        }
         break;
       case "filters.listen":
         onFilterMessage(message.action, message.args[0]);
         break;
       case "subscriptions.listen":
         onSubscriptionMessage(message.action, message.args[0]);
         break;
     }
   });
 
   ext.backgroundPage.sendMessage(
   {
     type: "app.listen",
     filter: ["addSubscription", "error"]
   });
   ext.backgroundPage.sendMessage(
   {
     type: "filters.listen",
     filter: ["added", "loaded", "removed"]
   });
   ext.backgroundPage.sendMessage(
   {
     type: "subscriptions.listen",
     filter: ["added", "disabled", "homepage", "lastDownload", "removed", "title"]
   });
 
   window.addEventListener("DOMContentLoaded", onDOMLoaded, false);
 })();