Bug 1204983 - Allow about: pages to load remote content (r=bholley,bz,florian,dragana)

browser/components/BrowserComponents.manifest

@@ -46,3 +46,5 @@ component {d8903bf6-68d5-4e97-bcd1-e4d3012f721a} nsBrowserGlue.js
 #ifndef MOZ_MULET
 contract @mozilla.org/content-permission/prompt;1 {d8903bf6-68d5-4e97-bcd1-e4d3012f721a}
 #endif
+component {97eea4bb-db50-4ae0-9147-1e5ed55b4ed5} nsBrowserGlue.js
+contract @mozilla.org/browser/aboutnewtab-service;1 {97eea4bb-db50-4ae0-9147-1e5ed55b4ed5}

browser/components/about/AboutRedirector.cpp

@@ -7,11 +7,14 @@
 
 #include "AboutRedirector.h"
 #include "nsNetUtil.h"
+#include "nsIAboutNewTabService.h"
 #include "nsIChannel.h"
 #include "nsIURI.h"
 #include "nsIScriptSecurityManager.h"
+#include "nsIProtocolHandler.h"
 #include "mozilla/ArrayUtils.h"
 #include "nsDOMString.h"
+#include "nsServiceManagerUtils.h"
 
 namespace mozilla {
 namespace browser {
@@ -176,14 +179,50 @@ AboutRedirector::NewChannel(nsIURI* aURI,
 
   for (int i = 0; i < kRedirTotal; i++) {
     if (!strcmp(path.get(), kRedirMap[i].id)) {
+      nsAutoCString url;
+
+      // check if about:newtab got overridden
+      if (path.EqualsLiteral("newtab")) {
+        nsCOMPtr<nsIAboutNewTabService> aboutNewTabService =
+          do_GetService("@mozilla.org/browser/aboutnewtab-service;1", &rv);
+        NS_ENSURE_SUCCESS(rv, rv);
+        bool overridden = false;
+        rv = aboutNewTabService->GetOverridden(&overridden);
+        NS_ENSURE_SUCCESS(rv, rv);
+        if (overridden) {
+          rv = aboutNewTabService->GetNewTabURL(url);
+          NS_ENSURE_SUCCESS(rv, rv);
+        }
+      }
+      // fall back to the specified url in the map
+      if (url.IsEmpty()) {
+        url.AssignASCII(kRedirMap[i].url);
+      }
+
       nsCOMPtr<nsIChannel> tempChannel;
       nsCOMPtr<nsIURI> tempURI;
-      rv = NS_NewURI(getter_AddRefs(tempURI),
-                     nsDependentCString(kRedirMap[i].url));
+      rv = NS_NewURI(getter_AddRefs(tempURI), url);
       NS_ENSURE_SUCCESS(rv, rv);
+
+      // If tempURI links to an external URI (i.e. something other than
+      // chrome:// or resource://) then set the LOAD_REPLACE flag on the
+      // channel which forces the channel owner to reflect the displayed
+      // URL rather then being the systemPrincipal.
+      bool isUIResource = false;
+      rv = NS_URIChainHasFlags(tempURI, nsIProtocolHandler::URI_IS_UI_RESOURCE,
+                               &isUIResource);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      nsLoadFlags loadFlags =
+        isUIResource ? static_cast<nsLoadFlags>(nsIChannel::LOAD_NORMAL)
+                     : static_cast<nsLoadFlags>(nsIChannel::LOAD_REPLACE);
+
       rv = NS_NewChannelInternal(getter_AddRefs(tempChannel),
                                  tempURI,
-                                 aLoadInfo);
+                                 aLoadInfo,
+                                 nullptr, // aLoadGroup
+                                 nullptr, // aCallbacks
+                                 loadFlags);
       NS_ENSURE_SUCCESS(rv, rv);
 
       tempChannel->SetOriginalURI(aURI);

browser/components/moz.build

@@ -30,6 +30,7 @@ DIRS += [
 DIRS += ['build']
 
 XPIDL_SOURCES += [
+    'nsIAboutNewTabService.idl',
     'nsIBrowserGlue.idl',
     'nsIBrowserHandler.idl',
 ]

browser/components/nsBrowserGlue.js

@@ -187,6 +187,8 @@ XPCOMUtils.defineLazyModuleGetter(this, "AppConstants",
 XPCOMUtils.defineLazyServiceGetter(this, "WindowsUIUtils",
                                    "@mozilla.org/windows-ui-utils;1", "nsIWindowsUIUtils");
 
+const ABOUT_NEWTAB = "about:newtab";
+
 const PREF_PLUGINS_NOTIFYUSER = "plugins.update.notifyUser";
 const PREF_PLUGINS_UPDATEURL  = "plugins.update.url";
 
@@ -2474,6 +2476,45 @@ BrowserGlue.prototype = {
   _xpcom_factory: BrowserGlueServiceFactory,
 }
 
+// ------------------------------------
+// nsIAboutNewTabService implementation
+//-------------------------------------
+
+function AboutNewTabService()
+{
+  this._newTabURL = ABOUT_NEWTAB;
+  this._overridden = false;
+}
+
+AboutNewTabService.prototype = {
+  classID: Components.ID("{97eea4bb-db50-4ae0-9147-1e5ed55b4ed5}"),
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIAboutNewTabService]),
+
+  get newTabURL() {
+    return this._newTabURL;
+  },
+
+  set newTabURL(aNewTabURL) {
+    if (aNewTabURL === ABOUT_NEWTAB) {
+      this.resetNewTabURL();
+      return;
+    }
+    this._newTabURL = aNewTabURL;
+    this._overridden = true;
+    Services.obs.notifyObservers(null, "newtab-url-changed", this._newTabURL);
+  },
+
+  get overridden() {
+    return this._overridden;
+  },
+
+  resetNewTabURL: function() {
+    this._newTabURL = ABOUT_NEWTAB;
+    this._overridden = false;
+    Services.obs.notifyObservers(null, "newtab-url-changed", this._newTabURL);
+   }
+};
+
 function ContentPermissionPrompt() {}
 
 ContentPermissionPrompt.prototype = {
@@ -3218,7 +3259,7 @@ var E10SUINotification = {
 };
 #endif
 
-var components = [BrowserGlue, ContentPermissionPrompt];
+var components = [BrowserGlue, ContentPermissionPrompt, AboutNewTabService];
 this.NSGetFactory = XPCOMUtils.generateNSGetFactory(components);
 
 

browser/components/nsIAboutNewTabService.idl

@@ -0,0 +1,32 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * Allows to override about:newtab to point to a different location
+ * than the one specified within AboutRedirector.cpp
+ */
+
+[scriptable, uuid(6c66f022-beb1-46ea-8af6-c6c6dd937ea9)]
+interface nsIAboutNewTabService : nsISupports
+{
+  /**
+   * Returns "about:newtab" if not overridden, otherwise
+   * a string represenation of the new URL.
+   */
+  attribute ACString newTabURL;
+
+  /**
+   * Returns true if the default of "about:newtab" got
+   * overridden.
+   */
+  readonly attribute bool overridden;
+
+  /**
+   * Resets "about:newtab" to the default and also resets the
+   * overridden attribute to false.
+   */
+  void resetNewTabURL();
+};

docshell/base/nsAboutRedirector.cpp

@@ -9,6 +9,7 @@
 #include "nsAboutProtocolUtils.h"
 #include "mozilla/ArrayUtils.h"
 #include "nsDOMString.h"
+#include "nsIProtocolHandler.h"
 
 NS_IMPL_ISUPPORTS(nsAboutRedirector, nsIAboutModule)
 
@@ -48,7 +49,7 @@ static RedirEntry kRedirMap[] = {
   { "crashes", "chrome://global/content/crashes.xhtml", 0 },
 #endif
   {
-    "credits", "http://www.mozilla.org/credits/",
+    "credits", "https://www.mozilla.org/credits/",
     nsIAboutModule::URI_SAFE_FOR_UNTRUSTED_CONTENT
   },
   {
@@ -143,12 +144,27 @@ nsAboutRedirector::NewChannel(nsIURI* aURI,
       nsCOMPtr<nsIURI> tempURI;
       rv = NS_NewURI(getter_AddRefs(tempURI), kRedirMap[i].url);
       NS_ENSURE_SUCCESS(rv, rv);
+
+      // If tempURI links to an external URI (i.e. something other than
+      // chrome:// or resource://) then set the LOAD_REPLACE flag on the
+      // channel which forces the channel owner to reflect the displayed
+      // URL rather then being the systemPrincipal.
+      bool isUIResource = false;
+      rv = NS_URIChainHasFlags(tempURI, nsIProtocolHandler::URI_IS_UI_RESOURCE,
+                               &isUIResource);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      nsLoadFlags loadFlags =
+        isUIResource ? static_cast<nsLoadFlags>(nsIChannel::LOAD_NORMAL)
+                     : static_cast<nsLoadFlags>(nsIChannel::LOAD_REPLACE);
+
       rv = NS_NewChannelInternal(getter_AddRefs(tempChannel),
                                  tempURI,
-                                 aLoadInfo);
-      if (NS_FAILED(rv)) {
-        return rv;
-      }
+                                 aLoadInfo,
+                                 nullptr, // aLoadGroup
+                                 nullptr, // aCallbacks
+                                 loadFlags);
+      NS_ENSURE_SUCCESS(rv, rv);
 
       tempChannel->SetOriginalURI(aURI);
 

netwerk/base/nsNetUtil.cpp

@@ -1533,18 +1533,6 @@ NS_TryToMakeImmutable(nsIURI *uri,
     return result.forget();
 }
 
-nsresult
-NS_URIChainHasFlags(nsIURI   *uri,
-                    uint32_t  flags,
-                    bool     *result)
-{
-    nsresult rv;
-    nsCOMPtr<nsINetUtil> util = do_GetNetUtil(&rv);
-    NS_ENSURE_SUCCESS(rv, rv);
-
-    return util->URIChainHasFlags(uri, flags, result);
-}
-
 already_AddRefed<nsIURI>
 NS_GetInnermostURI(nsIURI *aURI)
 {

netwerk/base/nsNetUtil.inl

@@ -88,6 +88,18 @@ net_EnsureIOService(nsIIOService **ios, nsCOMPtr<nsIIOService> &grip)
     return rv;
 }
 
+INLINE_IF_EXTERN nsresult
+NS_URIChainHasFlags(nsIURI   *uri,
+                    uint32_t  flags,
+                    bool     *result)
+{
+    nsresult rv;
+    nsCOMPtr<nsINetUtil> util = do_GetNetUtil(&rv);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    return util->URIChainHasFlags(uri, flags, result);
+}
+
 INLINE_IF_EXTERN nsresult
 NS_NewURI(nsIURI **result,
           const nsACString &spec,