Issue 3748 - Update URL Fixer dependency on buildtools to revision c92cc4e4a338 and make it E10S-co…

lib/child/typoNetError.js

Index: lib/child/typoNetError.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/child/typoNetError.js
@@ -0,0 +1,137 @@
+/*
+ * This file is part of the URL Fixer,
+ * Copyright (C) 2006-2016 Eyeo GmbH
+ *
+ * URL Fixer 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.
+ *
+ * URL Fixer is distributed in the hope that it will be useful,
+ * 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 URL Fixer.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+"use strict";
+
+const {classes: Cc, interfaces: Ci, utils: Cu} = Components;
+
+let {Services} = Cu.import("resource://gre/modules/Services.jsm", {});
+
+let onShutdown =
+{
+  shutdownHandlers: [],
+  done: false,
+  add: function(handler)
+  {
+    if (this.shutdownHandlers.indexOf(handler) < 0)
+      this.shutdownHandlers.push(handler);
+  },
+  remove: function(handler)
+  {
+    let index = this.shutdownHandlers.indexOf(handler);
+    if (index >= 0)
+      this.shutdownHandlers.splice(index, 1);
+  }
+};
+
+let netErrorOverlay = null;
+
+function receivedNetErrorOverlay(message)
+{
+  let parser = Cc["@mozilla.org/xmlextras/domparser;1"]
+                 .createInstance(Ci.nsIDOMParser);
+  netErrorOverlay = parser.parseFromString(message.data, "application/xml");

[Thomas Greiner, 2016/03/08 12:34:43]

Note that previously we were first loading the error overlay and then installing
the `WindowObserver` which installed the "DOMContentLoaded" listener. Now,
however, we're installing the "DOMContentLoaded" listener in parallel to
requesting the error overlay.

[Wladimir Palant, 2016/03/08 14:37:48]

Yes. There is a check for netErrorOverlay in the event handler so doing this
sequentially is unnecessary.

+}
+
+function shutdown(message)
+{
+  if (message.data == Components.stack.filename && !onShutdown.done)
+  {
+    onShutdown.done = true;
+    for (let i = onShutdown.shutdownHandlers.length - 1; i >= 0; i --)
+    {
+      try
+      {
+        onShutdown.shutdownHandlers[i]();
+      }
+      catch (e)
+      {
+        Cu.reportError(e);
+      }
+    }
+    onShutdown.shutdownHandlers = null;
+  }
+}
+
+function onDocumentCreated(subject, topic, data)
+{
+  if (topic != "content-document-global-created")

[Thomas Greiner, 2016/03/08 12:34:44]

Detail: Is this check necessary given that you've already specified in line 134
that you're only listening to "content-document-global-created"?

[Wladimir Palant, 2016/03/08 14:37:48]

It's a somewhat theoretical scenario but some misguided extension could be
calling observers directly (e.g. after obtaining a list via
nsIObserverService.enumerateObservers()) - and they might be calling with a
different topic because the observer they mean to trigger isn't ours at all.
Yes, those things happen...

+    return;
+  if (!(subject instanceof Ci.nsIDOMWindow))
+    return;
+
+  subject.addEventListener("DOMContentLoaded", handlePageLoad);

[Thomas Greiner, 2016/03/08 12:34:43]

Detail: We usually explicitly specify the "useCapture" argument.

[Wladimir Palant, 2016/03/08 14:37:48]

Well, we can stop doing that - it's optional ever since Firefox 6.

+}
+
+function handlePageLoad(event)
+{
+  let document = event.target;
+  if (document.documentURI.indexOf("about:neterror?") != 0 ||
+      document.documentURI.indexOf("e=netOffline") > 0 ||
+      document.documentURI.indexOf("e=notCached") > 0)
+  {
+    return;
+  }
+
+  if (!netErrorOverlay || document.getElementById("url-fixer-section"))
+    return;
+
+  let container = document.getElementById("errorPageContainer");
+  if (!container)
+    return;
+
+  container.appendChild(netErrorOverlay.documentElement.cloneNode(true));
+
+  let textField = document.getElementById("url-fixer-intention");
+  textField.value = document.defaultView.location.href;
+
+  let retryButton = document.getElementById("url-fixer-retry");
+  retryButton.addEventListener("click", function()
+  {
+    let newURL = textField.value.replace(/^\s+/, "").replace(/\s+$/, "");
+    if (!newURL.length)
+      return;
+
+    let [prefix, newHost, suffix] = parseURL(newURL);
+    let oldHost = document.defaultView.location.hostname.toLowerCase();
+
+    sendAsyncMessage("URLFixer:UserCorrection", {oldHost, newHost});
+
+    document.defaultView.location.replace(newURL);
+  }, false);
+}
+
+function parseURL(url)
+{
+  if (/^\s*((?:\w+:)?\/*(?:[^\/#]*@)?)([^\/:#]*)/.test(url))
+    return [RegExp.$1, RegExp.$2.toLowerCase(), RegExp.rightContext];
+  else
+    return [url, null, null];
+}
+
+addMessageListener("URLFixer:NetErrorOverlay", receivedNetErrorOverlay);
+addMessageListener("URLFixer:Shutdown", shutdown);
+onShutdown.add(() => {
+  removeMessageListener("URLFixer:NetErrorOverlay", receivedNetErrorOverlay);
+  removeMessageListener("URLFixer:Shutdown", shutdown);
+});
+sendAsyncMessage("URLFixer:GetNetErrorOverlay");
+
+Services.obs.addObserver(onDocumentCreated, "content-document-global-created", false);
+onShutdown.add(() => {
+  Services.obs.removeObserver(onDocumentCreated, "content-document-global-created");
+});