Allocation is leaked when `jack_activate` fails

[SludgePhD]

rust-jack/src/client/async_client.rs

Lines 59 to 76 in 50adcd0

	let mut callback_context = Box::new(CallbackContext {
	client,
	notification: notification_handler,
	process: process_handler,
	is_valid_for_callback: AtomicBool::new(true),
	has_panic: AtomicBool::new(false),
	});
	CallbackContext::register_callbacks(&mut callback_context)?;
	let res = j::jack_activate(callback_context.client.raw());
	match res {
	0 => Ok(AsyncClient {
	callback: Some(callback_context),
	}),
	_ => {
	mem::forget(callback_context);
	Err(Error::ClientActivationError)
	}
	}

The mem::forget will leak the callbacks and the Box that was allocated earlier in the method.

[SludgePhD]

It looks like there are unexplained mem::forget calls all over the library. If the intent is to prevent a malicious user error from panicking in Drop, that should probably be done without causing an unconditional memory leak.

[wmedrano]

We can probably do less mem::forget though I'd have to read the JACK API again.

If I recall, some of this was intentional. JACK may hold on to some references and it is unclear when it is absolutely clear to reclaim them. For example, perhaps the activate failed but JACK still wants to call the thread_init_callback or something.