Bug 1122553 - BroadcastChannel should keep FileImpl alive when sent to the PBackground actors, r=bent

dom/broadcastchannel/BroadcastChannelParent.cpp

@@ -82,8 +82,10 @@ BroadcastChannelParent::CheckAndDeliver(const ClonedMessageData& aData,
   AssertIsOnBackgroundThread();
 
   if (aOrigin == mOrigin && aChannel == mChannel) {
-    // We need to duplicate data only if we have blobs.
-    if (aData.blobsParent().IsEmpty()) {
+    // We need to duplicate data only if we have blobs or if the manager of
+    // them is different than the manager of this parent actor.
+    if (aData.blobsParent().IsEmpty() ||
+        static_cast<BlobParent*>(aData.blobsParent()[0])->GetBackgroundManager() == Manager()) {
       unused << SendNotify(aData);
       return;
     }

dom/broadcastchannel/BroadcastChannelService.cpp

@@ -5,6 +5,8 @@
 
 #include "BroadcastChannelService.h"
 #include "BroadcastChannelParent.h"
+#include "mozilla/dom/File.h"
+#include "mozilla/dom/ipc/BlobParent.h"
 #include "mozilla/ipc/BackgroundParent.h"
 
 #ifdef XP_WIN
@@ -89,6 +91,19 @@ struct MOZ_STACK_CLASS PostMessageData MOZ_FINAL
   {
     MOZ_ASSERT(aParent);
     MOZ_COUNT_CTOR(PostMessageData);
+
+    // We need to keep the array alive for the life-time of this
+    // PostMessageData.
+    if (!aData.blobsParent().IsEmpty()) {
+      mFiles.SetCapacity(aData.blobsParent().Length());
+
+      for (uint32_t i = 0, len = aData.blobsParent().Length(); i < len; ++i) {
+        nsRefPtr<FileImpl> impl =
+          static_cast<BlobParent*>(aData.blobsParent()[i])->GetBlobImpl();
+       MOZ_ASSERT(impl);
+       mFiles.AppendElement(impl);
+      }
+    }
   }
 
   ~PostMessageData()
@@ -98,6 +113,7 @@ struct MOZ_STACK_CLASS PostMessageData MOZ_FINAL
 
   BroadcastChannelParent* mParent;
   const ClonedMessageData& mData;
+  nsTArray<nsRefPtr<FileImpl>> mFiles;
   const nsString mOrigin;
   const nsString mChannel;
 };

dom/broadcastchannel/tests/test_broadcastchannel_any.html

@@ -75,15 +75,42 @@ function compare(a, b) {
 }
 
 function runTest() {
+  var count = 2;
+
   var bc = new BroadcastChannel("foobar");
   ok(bc, "BroadcastChannel can be created");
 
   bc.onmessage = function(event) {
+    ok(count < 2, "Still comparing...");
+    info("bc: " + currentTest);
     compare(event.data, currentTest);
+    ++count;
+    next();
+  }
+
+  var bc2 = new BroadcastChannel("foobar");
+  ok(bc2, "BroadcastChannel can be created");
+
+  var toSkip = true;
+  bc2.onmessage = function(event) {
+    toSkip = !toSkip;
+    if (toSkip) return;
+
+    ok(count < 2, "Still comparing...");
+    info("bc2: " + currentTest);
+    compare(event.data, currentTest);
+    ++count;
     next();
   }
 
   function next() {
+    if (count < 2) {
+      return;
+    }
+
+    is(count, 2, "Just 2 comparations");
+    count = 0;
+
     if (!tests.length) {
       SimpleTest.finish();
       return;
@@ -91,6 +118,7 @@ function runTest() {
 
     currentTest = tests.shift();
     bc.postMessage(currentTest);
+    info("Posted: " + currentTest);
   }
 
   var worker = new Worker("broadcastchannel_worker_any.js");