🩹 zm: do not reply if no-reply-expected flag is set

[manuelheiss-liebherr]

I am using zbus to define an inteface method, like this:

#[zbus::interface(name = "public.settings")]
impl SettingsInterface {
    async fn set_var(
        &self,
        originator: &str,
        object: &str,
        interface: &str,
        arguments: &str,
    ) {
        //...
    }
}

This method is called with with the NoReplyExpected flag. However zbus generates a reply, which ended up in an error shown in dbus-monitor:

Rejected send message, 0 matched rules; type="method_return", sender=":1.16" ...

I used cargo expand to see what code is generated by the interface macros and found something like this:

let reply = self.set_var(originator, object, interface, arguments).await;
let hdr = message.header();
connection.reply(&hdr, &reply).await

The connection.reply() method is called in every case. So i guess, that the flag is not evaluated yet, to handle the case where no response is expected!?

With my adjustment, the generated code looks like this:

let reply = self.set_var(originator, object, interface, arguments).await;
let hdr = message.header();
if hdr.primary().flags().contains(zbus::message::Flags::NoReplyExpected)
{
    Ok(())
} else {
    connection.reply(&hdr, &reply).await
}

And the error shown with dbus-monitor was gone.

[zeenix]

@manuelheiss-liebherr Thanks for this!

[zeenix]

Thanks so much! However you didn't add description to the git commit still and didn't add an emoji (as per our contributing guidelines). I'll do that for you this time but please keep in mind for any future contributions. 😊