One Shot signals do not disconnect before emission

[anty567567]

Tested versions

• Reproducible in Godot v4.2.2.stable.official [15073af]

System information

Windows 10, CPU - i9 12900K, GPU RTX 3070Ti

Issue description

When the callback for a signal that was connected using the CONNECTION_ONE_SHOT flag is processed, the connection is not disconnected as is suggested here in the source code:

This is shown by trying to make the same connection in the callback function and it throwing an error that the connection already exists:
E 0:00:27:0611 FamiliarAI.gd:42 @ make_decision(): Signal 'outgoing_done_acting' is already connected to given callable 'Node3D(FamiliarAI.gd)::recover' in that object.
<C++ Error> Method/function failed. Returning: ERR_INVALID_PARAMETER
<C++ Source> core/object/object.cpp:1358 @ connect()

Steps to reproduce

Run the mrp provided to see that the signal does not disconnect before calling the callable.

Minimal reproduction project (MRP)

mrp.zip

[kleonc]

Tested versions

• Reproducible in Godot v4.2.2.stable.official [15073af]

Issue description

When the callback for a signal that was connected using the CONNECTION_ONE_SHOT flag is processed, the connection is not disconnected as is suggested here in the source code:

That's not the source for v4.2.2.stable.official [15073af], here's the actual source (check the commit hash):

godot/core/object/object.cpp

Lines 1094 to 1166 in 15073af

	List<_ObjectSignalDisconnectData> disconnect_data;
	// Ensure that disconnecting the signal or even deleting the object
	// will not affect the signal calling.
	LocalVector<Connection> slot_conns;
	slot_conns.resize(s->slot_map.size());
	{
	uint32_t idx = 0;
	for (const KeyValue<Callable, SignalData::Slot> &slot_kv : s->slot_map) {
	slot_conns[idx++] = slot_kv.value.conn;
	}
	DEV_ASSERT(idx == s->slot_map.size());
	}
	OBJ_DEBUG_LOCK
	Error err = OK;
	for (const Connection &c : slot_conns) {
	if (!c.callable.is_valid()) {
	// Target might have been deleted during signal callback, this is expected and OK.
	continue;
	}
	const Variant **args = p_args;
	int argc = p_argcount;
	if (c.flags & CONNECT_DEFERRED) {
	MessageQueue::get_singleton()->push_callablep(c.callable, args, argc, true);
	} else {
	Callable::CallError ce;
	_emitting = true;
	Variant ret;
	c.callable.callp(args, argc, ret, ce);
	_emitting = false;
	if (ce.error != Callable::CallError::CALL_OK) {
	#ifdef DEBUG_ENABLED
	if (c.flags & CONNECT_PERSIST && Engine::get_singleton()->is_editor_hint() && (script.is_null() || !Ref<Script>(script)->is_tool())) {
	continue;
	}
	#endif
	Object *target = c.callable.get_object();
	if (ce.error == Callable::CallError::CALL_ERROR_INVALID_METHOD && target && !ClassDB::class_exists(target->get_class_name())) {
	//most likely object is not initialized yet, do not throw error.
	} else {
	ERR_PRINT("Error calling from signal '" + String(p_name) + "' to callable: " + Variant::get_callable_error_text(c.callable, args, argc, ce) + ".");
	err = ERR_METHOD_NOT_FOUND;
	}
	}
	}
	bool disconnect = c.flags & CONNECT_ONE_SHOT;
	#ifdef TOOLS_ENABLED
	if (disconnect && (c.flags & CONNECT_PERSIST) && Engine::get_singleton()->is_editor_hint()) {
	//this signal was connected from the editor, and is being edited. just don't disconnect for now
	disconnect = false;
	}
	#endif
	if (disconnect) {
	_ObjectSignalDisconnectData dd;
	dd.signal = p_name;
	dd.callable = c.callable;
	disconnect_data.push_back(dd);
	}
	}
	while (!disconnect_data.is_empty()) {
	const _ObjectSignalDisconnectData &dd = disconnect_data.front()->get();
	_disconnect(dd.signal, dd.callable);
	disconnect_data.pop_front();
	}

---

Fixed by #89451 (since v4.3.dev6.official [89850d5]).

MRP of course still results in stack overflow, according to the code. But no more errors. From v4.3.rc2.official [3978628]: