From fdecca2f18a7b2a9653afb07143767b3fa4bb11f Mon Sep 17 00:00:00 2001
From: Raul Santos <raulsntos@gmail.com>
Date: Sun, 6 Apr 2025 19:55:34 +0200
Subject: [PATCH] Add `recording_signals` to MissingNode

Allows connecting unknown signals to MissingNode so they aren't lost when the Node type is missing.
---
 doc/classes/MissingNode.xml |  3 +++
 scene/main/missing_node.cpp | 23 +++++++++++++++++++++++
 scene/main/missing_node.h   |  8 ++++++++
 3 files changed, 34 insertions(+)

diff --git a/doc/classes/MissingNode.xml b/doc/classes/MissingNode.xml
index 9171c8321f2..d6d1ac0f01a 100644
--- a/doc/classes/MissingNode.xml
+++ b/doc/classes/MissingNode.xml
@@ -19,5 +19,8 @@
 		<member name="recording_properties" type="bool" setter="set_recording_properties" getter="is_recording_properties">
 			If [code]true[/code], allows new properties to be set along with existing ones. If [code]false[/code], only existing properties' values can be set, and new properties cannot be added.
 		</member>
+		<member name="recording_signals" type="bool" setter="set_recording_signals" getter="is_recording_signals">
+			If [code]true[/code], allows new signals to be connected to along with existing ones. If [code]false[/code], only existing signals can be connected to, and new signals cannot be added.
+		</member>
 	</members>
 </class>
diff --git a/scene/main/missing_node.cpp b/scene/main/missing_node.cpp
index f071ea59a0a..10d426dd018 100644
--- a/scene/main/missing_node.cpp
+++ b/scene/main/missing_node.cpp
@@ -58,6 +58,17 @@ void MissingNode::_get_property_list(List<PropertyInfo> *p_list) const {
 	}
 }
 
+#ifdef DEBUG_ENABLED
+Error MissingNode::connect(const StringName &p_signal, const Callable &p_callable, uint32_t p_flags) {
+	if (is_recording_signals()) {
+		if (!has_signal(p_signal)) {
+			add_user_signal(MethodInfo(p_signal));
+		}
+	}
+	return Object::connect(p_signal, p_callable, p_flags);
+}
+#endif
+
 void MissingNode::set_original_class(const String &p_class) {
 	original_class = p_class;
 }
@@ -82,6 +93,14 @@ bool MissingNode::is_recording_properties() const {
 	return recording_properties;
 }
 
+void MissingNode::set_recording_signals(bool p_enable) {
+	recording_signals = p_enable;
+}
+
+bool MissingNode::is_recording_signals() const {
+	return recording_signals;
+}
+
 PackedStringArray MissingNode::get_configuration_warnings() const {
 	// The mere existence of this node is warning.
 	PackedStringArray warnings = Node::get_configuration_warnings();
@@ -107,10 +126,14 @@ void MissingNode::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_recording_properties", "enable"), &MissingNode::set_recording_properties);
 	ClassDB::bind_method(D_METHOD("is_recording_properties"), &MissingNode::is_recording_properties);
 
+	ClassDB::bind_method(D_METHOD("set_recording_signals", "enable"), &MissingNode::set_recording_signals);
+	ClassDB::bind_method(D_METHOD("is_recording_signals"), &MissingNode::is_recording_signals);
+
 	// Expose, but not save.
 	ADD_PROPERTY(PropertyInfo(Variant::STRING, "original_class", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NONE), "set_original_class", "get_original_class");
 	ADD_PROPERTY(PropertyInfo(Variant::STRING, "original_scene", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NONE), "set_original_scene", "get_original_scene");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "recording_properties", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NONE), "set_recording_properties", "is_recording_properties");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "recording_signals", PROPERTY_HINT_NONE, "", PROPERTY_USAGE_NONE), "set_recording_signals", "is_recording_signals");
 }
 
 MissingNode::MissingNode() {
diff --git a/scene/main/missing_node.h b/scene/main/missing_node.h
index b986655e748..c8681b90f87 100644
--- a/scene/main/missing_node.h
+++ b/scene/main/missing_node.h
@@ -39,12 +39,17 @@ class MissingNode : public Node {
 	String original_class;
 	String original_scene;
 	bool recording_properties = false;
+	bool recording_signals = false;
 
 protected:
 	bool _set(const StringName &p_name, const Variant &p_value);
 	bool _get(const StringName &p_name, Variant &r_ret) const;
 	void _get_property_list(List<PropertyInfo> *p_list) const;
 
+#ifdef DEBUG_ENABLED
+	virtual Error connect(const StringName &p_signal, const Callable &p_callable, uint32_t p_flags = 0) override;
+#endif
+
 	static void _bind_methods();
 
 public:
@@ -57,6 +62,9 @@ public:
 	void set_recording_properties(bool p_enable);
 	bool is_recording_properties() const;
 
+	void set_recording_signals(bool p_enable);
+	bool is_recording_signals() const;
+
 	virtual PackedStringArray get_configuration_warnings() const override;
 
 	MissingNode();