1462676 - StructuredCloneData move constructor is a bit suspect

Status: NEW

(Core :: DOM: Content Processes, enhancement, P2)

Description

[Ben Kelly [:bkelly, not reviewing]]

The StructuredCloneData move constructor/assignment currently looks like this:

  mExternalData = Move(aOther.mExternalData);
  mSharedData = Move(aOther.mSharedData);
  mIPCStreams = Move(aOther.mIPCStreams);
  mInitialized = aOther.mInitialized;

This is all well and good I suppose, but it is at least missing some data from the base class.

For example, it does not move over mPortIdentifiers at all.  This means if you move a StructuredCloneData for a message that contains a transferred MessagePort then you will hit this debug assertion:

https://searchfox.org/mozilla-central/rev/d4b9e50875ad7e5d20f2fee6a53418315f6dfcc0/dom/base/StructuredCloneHolder.cpp#1155

Also, I recently removed the base StructuredCloneHolder move constructor because it was broken.  It did not update the bare closure pointer it passed to the JS APIs.

I tried removing the StructuredCloneData move constructor/assignment but it broke the build.  It seems we are using this type in an nsTArray that wants to use move semantics somewhere.

Andrew, Andrea, what do you think the right thing to do here is?

Comment 1

[Marion Daly [:mdaly]]

adding to DWS_NEXT, removing need-info