Signals not received in XML-generated client proxy

[michab66]

Our problem is that we do not receive dbus signals in the client proxy. We have a slight deviation from the examples and that allows to reproduce the problem.

The deviation resulted from the root-problem that connection to the session bus does not work implicitly as the examples assume. We start the dbus-daemon like so:

export DBUS_SESSION_BUS_ADDRESS='dbus-daemon --session --fork --print-address'

As a consequence the environment var DBUS_SESSION_BUS_ADDRESS is set and valid. An example value is unix:path=/tmp/dbus-5LFMrsYHha,guid=282be972820b34d88ecb4351640afde8.

After that we send a request with the following code (this is the adapted code from the XML-based concatenate example code:

    ...
    const char* objectPath = "/org/sdbuscpp/concatenator";

   // Modified code start
    auto connection = sdbus::createSessionBusConnection();
    ConcatenatorProxy concatenatorProxy(*connection, destinationName, objectPath);
   // Modified code end

    std::vector<int> numbers = {1, 2, ...

The proxy constructer implementation that handles the connection looks like:

    ConcatenatorProxy(
        sdbus::IConnection& connection, std::string destination, std::string objectPath)
        : ProxyInterfaces(connection, std::move(destination), std::move(objectPath))
    {
        registerProxy();
    }

The request of the concatenate operation is working, but the signal that is emitted is not received by the proxy.

I have read #25 which seems to be similar to our problem, but we cannot std::move the connection created by `sdbus::createSessionBusConnection()' since we receive a pointer on the IConnection instance but the APIs expect a reference.

Is there a way that sdbus-c++ automatically uses the DBUS_SESSION_BUS_ADDRESS? The samples do not need to explicitly create the connection and seem to work so we must do something wrong.

Is there something that needs additionally to be done if we explicitly manage the connection as shown?