Bug 677638 - MessageChannel and MessagePort disabled by pref, r=smaug

dom/base/MessageChannel.cpp

@@ -4,6 +4,7 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 #include "MessageChannel.h"
+#include "mozilla/Preferences.h"
 #include "mozilla/dom/MessageChannelBinding.h"
 #include "mozilla/dom/MessagePort.h"
 #include "nsContentUtils.h"
@@ -21,6 +22,24 @@ NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(MessageChannel)
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
+namespace {
+  bool gPrefInitialized = false;
+  bool gPrefEnabled = false;
+
+}
+
+
+/* static */ bool
+MessageChannel::PrefEnabled()
+{
+  if (!gPrefInitialized) {
+    Preferences::AddBoolVarCache(&gPrefEnabled, "dom.messageChannel.enabled");
+    gPrefInitialized = true;
+  }
+
+  return gPrefEnabled;
+}
+
 MessageChannel::MessageChannel(nsPIDOMWindow* aWindow)
   : mWindow(aWindow)
 {

dom/base/MessageChannel.h

@@ -28,6 +28,8 @@ public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(MessageChannel)
 
+  static bool PrefEnabled();
+
 public:
   MessageChannel(nsPIDOMWindow* aWindow);
 

dom/base/nsGlobalWindow.cpp

@@ -189,6 +189,7 @@
 #include "prenv.h"
 #include "prprf.h"
 
+#include "mozilla/dom/MessageChannel.h"
 #include "mozilla/dom/MessagePort.h"
 #include "mozilla/dom/MessagePortBinding.h"
 #include "mozilla/dom/indexedDB/IDBFactory.h"
@@ -6782,7 +6783,7 @@ PostMessageReadStructuredClone(JSContext* cx,
     }
   }
 
-  if (tag == SCTAG_DOM_MESSAGEPORT) {
+  if (MessageChannel::PrefEnabled() && tag == SCTAG_DOM_MESSAGEPORT) {
     NS_ASSERTION(!data, "Data should be empty");
 
     MessagePort* port;
@@ -6837,14 +6838,16 @@ PostMessageWriteStructuredClone(JSContext* cx,
              scInfo->event->StoreISupports(supports);
   }
 
-  MessagePort* port = nullptr;
-  nsresult rv = UNWRAP_OBJECT(MessagePort, cx, obj, port);
-  if (NS_SUCCEEDED(rv) && scInfo->subsumes) {
-    nsRefPtr<MessagePort> newPort = port->Clone(scInfo->window);
+  if (MessageChannel::PrefEnabled()) {
+    MessagePort* port = nullptr;
+    nsresult rv = UNWRAP_OBJECT(MessagePort, cx, obj, port);
+    if (NS_SUCCEEDED(rv) && scInfo->subsumes) {
+      nsRefPtr<MessagePort> newPort = port->Clone(scInfo->window);
 
-    return JS_WriteUint32Pair(writer, SCTAG_DOM_MESSAGEPORT, 0) &&
-           JS_WriteBytes(writer, &newPort, sizeof(newPort)) &&
-           scInfo->event->StoreISupports(newPort);
+      return JS_WriteUint32Pair(writer, SCTAG_DOM_MESSAGEPORT, 0) &&
+             JS_WriteBytes(writer, &newPort, sizeof(newPort)) &&
+             scInfo->event->StoreISupports(newPort);
+    }
   }
 
   const JSStructuredCloneCallbacks* runtimeCallbacks =

dom/base/test/Makefile.in

@@ -41,6 +41,7 @@ MOCHITEST_FILES = \
   test_messageChannel_pingpong.html \
   iframe_messageChannel_pingpong.html \
   test_messageChannel_unshipped.html \
+  test_messageChannel_pref.html \
   $(NULL)
 
 MOCHITEST_CHROME_FILES = \

dom/base/test/test_messageChannel.html

@@ -21,23 +21,29 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=677638
 </pre>
   <script type="application/javascript">
 
-  /** Test for Bug 677638 **/
-  var a = new MessageChannel();
-  ok(a, "MessageChannel created");
+  function runTest() {
+    /** Test for Bug 677638 **/
+    var a = new MessageChannel();
+    ok(a, "MessageChannel created");
 
-  var port1 = a.port1;
-  ok(port1, "MessageChannel.port1 exists");
-  is(port1, a.port1, "MessageChannel.port1 is port1");
+    var port1 = a.port1;
+    ok(port1, "MessageChannel.port1 exists");
+    is(port1, a.port1, "MessageChannel.port1 is port1");
 
-  var port2 = a.port2;
-  ok(port2, "MessageChannel.port1 exists");
-  is(port2, a.port2, "MessageChannel.port2 is port2");
+    var port2 = a.port2;
+    ok(port2, "MessageChannel.port1 exists");
+    is(port2, a.port2, "MessageChannel.port2 is port2");
 
-  [ 'postMessage', 'start', 'close' ].forEach(function(e) {
-    ok(e in port1, "MessagePort1." + e + " exists");
-    ok(e in port2, "MessagePort2." + e + " exists");
-  });
+    [ 'postMessage', 'start', 'close' ].forEach(function(e) {
+      ok(e in port1, "MessagePort1." + e + " exists");
+      ok(e in port2, "MessagePort2." + e + " exists");
+    });
 
+    SimpleTest.finish();
+  }
+
+  SimpleTest.waitForExplicitFinish();
+  SpecialPowers.pushPrefEnv({"set": [["dom.messageChannel.enabled", true]]}, runTest);
   </script>
 </body>
 </html>

dom/base/test/test_messageChannel_cloning.html

@@ -64,7 +64,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=677638
   }
 
   SimpleTest.waitForExplicitFinish();
-  runTest();
+  SpecialPowers.pushPrefEnv({"set": [["dom.messageChannel.enabled", true]]}, runTest);
   </script>
 </body>
 </html>

dom/base/test/test_messageChannel_pingpong.html

@@ -16,59 +16,62 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=677638
 </pre>
   <script type="application/javascript">
 
-  var MAX = 100;
+  function runTest() {
+    var MAX = 100;
 
-  var a = new MessageChannel();
-  ok(a, "MessageChannel created");
+    var a = new MessageChannel();
+    ok(a, "MessageChannel created");
 
-  // Populate the message queue of this port.
-  for (var i = 0; i < MAX; ++i) {
-    a.port1.postMessage(i);
-  }
+    // Populate the message queue of this port.
+    for (var i = 0; i < MAX; ++i) {
+      a.port1.postMessage(i);
+    }
 
-  window.addEventListener('message', receiveMessage, false);
-  function receiveMessage(evt) {
+    window.addEventListener('message', receiveMessage, false);
+    function receiveMessage(evt) {
 
-    // This test sends the port from this window to the iframe and viceversa.
-    if (evt.data.type == 'PORT') {
-      var port = evt.data.port;
-      var counter = 0;
-      port.onmessage = function(evt) {
-        // only 1 message should be received by this port.
-        if (counter++ == 0) {
-          ok(evt.data % 2, "The number " + evt.data + " has been received correctly by the main window");
+      // This test sends the port from this window to the iframe and viceversa.
+      if (evt.data.type == 'PORT') {
+        var port = evt.data.port;
+        var counter = 0;
+        port.onmessage = function(evt) {
+          // only 1 message should be received by this port.
+          if (counter++ == 0) {
+            ok(evt.data % 2, "The number " + evt.data + " has been received correctly by the main window");
 
-          if (evt.data < MAX - 1) {
-            ifr.contentWindow.postMessage({ type: 'PORT', port: port }, '*');
+            if (evt.data < MAX - 1) {
+              ifr.contentWindow.postMessage({ type: 'PORT', port: port }, '*');
+            } else {
+              SimpleTest.finish();
+            }
           } else {
-            SimpleTest.finish();
+            ok(false, "Wrong message!");
           }
-        } else {
-          ok(false, "Wrong message!");
         }
+      } else if (evt.data.type == 'OK') {
+        ok(true, evt.data.msg);
+      } else if (evt.data.type == 'KO') {
+        ok(false, evt.data.msg);
+      } else {
+        ok(false, "Unknown message");
       }
-    } else if (evt.data.type == 'OK') {
-      ok(true, evt.data.msg);
-    } else if (evt.data.type == 'KO') {
-      ok(false, evt.data.msg);
-    } else {
-      ok(false, "Unknown message");
+    }
+
+    var div = document.getElementById("content");
+    ok(div, "Parent exists");
+
+    var ifr = document.createElement("iframe");
+    ifr.addEventListener("load", iframeLoaded, false);
+    ifr.setAttribute('src', "iframe_messageChannel_pingpong.html");
+    div.appendChild(ifr);
+
+    function iframeLoaded() {
+      ifr.contentWindow.postMessage({ type: 'PORT', port: a.port2 }, '*');
     }
   }
 
-  var div = document.getElementById("content");
-  ok(div, "Parent exists");
-
-  var ifr = document.createElement("iframe");
-  ifr.addEventListener("load", iframeLoaded, false);
-  ifr.setAttribute('src', "iframe_messageChannel_pingpong.html");
-  div.appendChild(ifr);
-
-  function iframeLoaded() {
-    ifr.contentWindow.postMessage({ type: 'PORT', port: a.port2 }, '*');
-  }
-
   SimpleTest.waitForExplicitFinish();
+  SpecialPowers.pushPrefEnv({"set": [["dom.messageChannel.enabled", true]]}, runTest);
   </script>
 </body>
 </html>

dom/base/test/test_messageChannel_post.html

@@ -16,54 +16,57 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=677638
 </pre>
   <script type="application/javascript">
 
-  var a = new MessageChannel();
-  ok(a, "MessageChannel created");
+  function start() {
+    var a = new MessageChannel();
+    ok(a, "MessageChannel created");
 
-  window.addEventListener('message', receiveMessage, false);
-  function receiveMessage(evt) {
-    if (evt.data.status == 'READY') {
+    window.addEventListener('message', receiveMessage, false);
+    function receiveMessage(evt) {
+      if (evt.data.status == 'READY') {
+        runTest();
+      } else {
+        ok(false, "Unknown message");
+      }
+    }
+
+    var div = document.getElementById("content");
+    ok(div, "Parent exists");
+
+    var ifr = document.createElement("iframe");
+    ifr.addEventListener("load", iframeLoaded, false);
+    ifr.setAttribute('src', "iframe_messageChannel_post.html");
+    div.appendChild(ifr);
+
+    function iframeLoaded() {
+      ifr.contentWindow.postMessage({ port: a.port2 }, '*');
+    }
+
+    var tests = [ 42,
+                  null,
+                  undefined,
+                  "hello world",
+                  new Blob([]),
+                  true ];
+
+    a.port1.onmessage = function(evt) {
+      ok(tests.length, "We are waiting for a message");
+      is(tests[0], evt.data, "Value ok: " + tests[0]);
+      tests.shift();
       runTest();
-    } else {
-      ok(false, "Unknown message");
-    }
-  }
-
-  var div = document.getElementById("content");
-  ok(div, "Parent exists");
-
-  var ifr = document.createElement("iframe");
-  ifr.addEventListener("load", iframeLoaded, false);
-  ifr.setAttribute('src', "iframe_messageChannel_post.html");
-  div.appendChild(ifr);
-
-  function iframeLoaded() {
-    ifr.contentWindow.postMessage({ port: a.port2 }, '*');
-  }
-
-  var tests = [ 42,
-                null,
-                undefined,
-                "hello world",
-                new Blob([]),
-                true ];
-
-  a.port1.onmessage = function(evt) {
-    ok(tests.length, "We are waiting for a message");
-    is(tests[0], evt.data, "Value ok: " + tests[0]);
-    tests.shift();
-    runTest();
-  }
-
-  function runTest() {
-    if (!tests.length) {
-      SimpleTest.finish();
-      return;
     }
 
-    a.port1.postMessage(tests[0]);
+    function runTest() {
+      if (!tests.length) {
+        SimpleTest.finish();
+        return;
+      }
+
+      a.port1.postMessage(tests[0]);
+    }
   }
 
   SimpleTest.waitForExplicitFinish();
+  SpecialPowers.pushPrefEnv({"set": [["dom.messageChannel.enabled", true]]}, start);
   </script>
 </body>
 </html>

dom/base/test/test_messageChannel_pref.html

@@ -0,0 +1,42 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=677638
+-->
+<head>
+  <meta charset="utf-8">
+  <title>Test for Bug 677638 - pref</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=677638">Mozilla Bug 677638</a>
+<div id="content"></div>
+<pre id="test">
+</pre>
+  <script type="application/javascript">
+
+  function runTest(what) {
+    var status;
+    try {
+      status = MessageChannel;
+      ok(what, "Should MessageChannel exist?");
+    } catch(e) {
+      ok(!what, "Should MessageChannel exist?");
+    }
+    try {
+      status = MessagePort;
+      ok(what, "Should MessagePort exist?");
+    } catch(e) {
+      ok(!what, "Should MessagePort exist?");
+    }
+  }
+
+  SimpleTest.waitForExplicitFinish();
+
+  runTest(false);
+  SpecialPowers.pushPrefEnv({"set": [["dom.messageChannel.enabled", true]]},
+                            function() { runTest(true); SimpleTest.finish(); });
+  </script>
+</body>
+</html>

dom/base/test/test_messageChannel_start.html

@@ -228,7 +228,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=677638
   ];
 
   SimpleTest.waitForExplicitFinish();
-  runTests();
+  SpecialPowers.pushPrefEnv({"set": [["dom.messageChannel.enabled", true]]}, runTests);
   </script>
 </body>
 </html>

dom/base/test/test_messageChannel_transferable.html

@@ -16,49 +16,52 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=677638
 </pre>
   <script type="application/javascript">
 
-  var a = new MessageChannel();
-  ok(a, "MessageChannel created");
+  function start() {
+    var a = new MessageChannel();
+    ok(a, "MessageChannel created");
 
-  window.addEventListener('message', receiveMessage, false);
-  function receiveMessage(evt) {
-    if (evt.data.status == 'READY') {
-      runTest();
-    } else {
-      ok(false, "Unknown message");
+    window.addEventListener('message', receiveMessage, false);
+    function receiveMessage(evt) {
+      if (evt.data.status == 'READY') {
+        runTest();
+      } else {
+        ok(false, "Unknown message");
+      }
+    }
+
+    var div = document.getElementById("content");
+    ok(div, "Parent exists");
+
+    var ifr = document.createElement("iframe");
+    ifr.addEventListener("load", iframeLoaded, false);
+    ifr.setAttribute('src', "iframe_messageChannel_post.html");
+    div.appendChild(ifr);
+
+    function iframeLoaded() {
+      ifr.contentWindow.postMessage({ port: a.port2 }, '*');
+    }
+
+    a.port1.addEventListener('message', receivePortMessage, false);
+    function receivePortMessage(evt) {
+      is(evt.data.ab.byteLength, size, "The size is: " + size + " == " + ab.byteLength);
+      SimpleTest.finish();
+    }
+
+    // Start() is not implicity invoked when addEventListener is used.
+    a.port1.start();
+
+    var size = 1024 * 1024 * 32;
+    var ab = new ArrayBuffer(size);
+    is(ab.byteLength, size, "The size is: " + size + " == " + ab.byteLength);
+
+    function runTest() {
+      a.port1.postMessage({ab: ab, cb: ab}, [ab]);
+      ok(ab.byteLength == 0, "PostMessage - The size is: 0 == " + ab.byteLength)
     }
   }
 
-  var div = document.getElementById("content");
-  ok(div, "Parent exists");
-
-  var ifr = document.createElement("iframe");
-  ifr.addEventListener("load", iframeLoaded, false);
-  ifr.setAttribute('src', "iframe_messageChannel_post.html");
-  div.appendChild(ifr);
-
-  function iframeLoaded() {
-    ifr.contentWindow.postMessage({ port: a.port2 }, '*');
-  }
-
-  a.port1.addEventListener('message', receivePortMessage, false);
-  function receivePortMessage(evt) {
-    is(evt.data.ab.byteLength, size, "The size is: " + size + " == " + ab.byteLength);
-    SimpleTest.finish();
-  }
-
-  // Start() is not implicity invoked when addEventListener is used.
-  a.port1.start();
-
-  var size = 1024 * 1024 * 32;
-  var ab = new ArrayBuffer(size);
-  is(ab.byteLength, size, "The size is: " + size + " == " + ab.byteLength);
-
-  function runTest() {
-    a.port1.postMessage({ab: ab, cb: ab}, [ab]);
-    ok(ab.byteLength == 0, "PostMessage - The size is: 0 == " + ab.byteLength)
-  }
-
   SimpleTest.waitForExplicitFinish();
+  SpecialPowers.pushPrefEnv({"set": [["dom.messageChannel.enabled", true]]}, start);
   </script>
 </body>
 </html>

dom/base/test/test_messageChannel_unshipped.html

@@ -117,7 +117,7 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=677638
   }
 
   SimpleTest.waitForExplicitFinish();
-  runTests();
+  SpecialPowers.pushPrefEnv({"set": [["dom.messageChannel.enabled", true]]}, runTests);
   </script>
 </body>
 </html>

dom/webidl/MessageChannel.webidl

@@ -7,7 +7,7 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#channel-messaging
  */
 
-[Constructor]
+[Constructor, Pref="dom.messageChannel.enabled"]
 interface MessageChannel {
   readonly attribute MessagePort port1;
   readonly attribute MessagePort port2;

dom/webidl/MessagePort.webidl

@@ -7,6 +7,7 @@
  * http://www.whatwg.org/specs/web-apps/current-work/#channel-messaging
  */
 
+[Pref="dom.messageChannel.enabled"]
 interface MessagePort : EventTarget {
   // TODO void postMessage(any message, optional sequence<Transferable> transfer);
   [Throws]