DataConsumer::Close() crash

[binxie33]

In DataConsumer::Close() we should UnregisterObserver first before closing, otherwise it will crash.

         /**
     * Closes the DataConsumer.
     */
    void DataConsumer::Close()
    {
        MSC_TRACE();

        if (this->closed)
            return;

        this->closed = true;
        this->dataChannel->UnregisterObserver();  // here is the fix
        this->dataChannel->Close();
        this->privateListener->OnClose(this);
    }

[jmillan]

does it actually crash currently?

[jmillan]

This should not be needed, otherwise we won't get the 'close' state changed from the underlaying datachannel.

More than that, if we get events from the underlaying datachannel after closing it, that would be a but in libwebrtc.