From ccede712916f3b9f495138bf67f744735dacef7e Mon Sep 17 00:00:00 2001
From: Simon <MGVguy@gmail.com>
Date: Wed, 26 Nov 2025 11:00:30 +0900
Subject: [PATCH] Fix ClassDB crash caused by HashMap reallocation invalidating
 parent_ptr

---
 include/godot_cpp/core/class_db.hpp |  7 -------
 src/core/class_db.cpp               | 24 ++++++++++++++++++++----
 2 files changed, 20 insertions(+), 11 deletions(-)

diff --git a/include/godot_cpp/core/class_db.hpp b/include/godot_cpp/core/class_db.hpp
index b14f597a2..1a2b5f9d7 100644
--- a/include/godot_cpp/core/class_db.hpp
+++ b/include/godot_cpp/core/class_db.hpp
@@ -90,8 +90,6 @@ class ClassDB {
 		AHashMap<StringName, VirtualMethod> virtual_methods;
 		std::set<StringName> property_names;
 		std::set<StringName> constant_names;
-		// Pointer to the parent custom class, if any. Will be null if the parent class is a Godot class.
-		ClassInfo *parent_ptr = nullptr;
 	};
 
 private:
@@ -233,11 +231,6 @@ void ClassDB::_register_class(bool p_virtual, bool p_exposed, bool p_runtime) {
 	cl.name = T::get_class_static();
 	cl.parent_name = T::get_parent_class_static();
 	cl.level = current_level;
-	AHashMap<StringName, ClassInfo>::Iterator parent_it = classes.find(cl.parent_name);
-	if (parent_it != classes.end()) {
-		// Assign parent if it is also a custom class
-		cl.parent_ptr = &parent_it->value;
-	}
 	classes[cl.name] = cl;
 	class_register_order.push_back(cl.name);
 
diff --git a/src/core/class_db.cpp b/src/core/class_db.cpp
index 11f7b0778..9b8ecbe70 100644
--- a/src/core/class_db.cpp
+++ b/src/core/class_db.cpp
@@ -118,8 +118,13 @@ MethodBind *ClassDB::get_method(const StringName &p_class, const StringName &p_m
 		if (method != type->method_map.end()) {
 			return method->value;
 		}
-		type = type->parent_ptr;
-		continue;
+
+		AHashMap<StringName, ClassInfo>::Iterator parent_it = classes.find(type->parent_name);
+		if (parent_it == classes.end()) {
+			break;
+		}
+
+		type = &parent_it->value;
 	}
 
 	return nullptr;
@@ -243,7 +248,13 @@ void ClassDB::add_signal(const StringName &p_class, const MethodInfo &p_signal)
 	ClassInfo *check = &cl;
 	while (check) {
 		ERR_FAIL_COND_MSG(check->signal_names.find(p_signal.name) != check->signal_names.end(), String("Class '{0}' already has signal '{1}'.").format(Array::make(p_class, p_signal.name)));
-		check = check->parent_ptr;
+
+		AHashMap<StringName, ClassInfo>::Iterator parent_it = classes.find(check->parent_name);
+		if (parent_it == classes.end()) {
+			break;
+		}
+
+		check = &parent_it->value;
 	}
 
 	// register our signal in our plugin
@@ -303,7 +314,12 @@ GDExtensionClassCallVirtual ClassDB::get_virtual_func(void *p_userdata, GDExtens
 			return method_it->value.func;
 		}
 
-		type = type->parent_ptr;
+		AHashMap<StringName, ClassInfo>::Iterator parent_it = classes.find(type->parent_name);
+		if (parent_it == classes.end()) {
+			break;
+		}
+
+		type = &parent_it->value;
 	}
 
 	return nullptr;