5 files changed, 29 insertions, 1 deletions

diff --git a/core/extension/gdextension.cpp b/core/extension/gdextension.cpp
index 9674acb894..fda2be2086 100644
--- a/core/extension/gdextension.cpp
+++ b/core/extension/gdextension.cpp
@@ -292,6 +292,7 @@ void GDExtension::_register_extension_class(GDExtensionClassLibraryPtr p_library
 		p_extension_funcs->free_property_list_func, // GDExtensionClassFreePropertyList free_property_list_func;
 		p_extension_funcs->property_can_revert_func, // GDExtensionClassPropertyCanRevert property_can_revert_func;
 		p_extension_funcs->property_get_revert_func, // GDExtensionClassPropertyGetRevert property_get_revert_func;
+		nullptr, // GDExtensionClassValidateProperty validate_property_func;
 		nullptr, // GDExtensionClassNotification2 notification_func;
 		p_extension_funcs->to_string_func, // GDExtensionClassToString to_string_func;
 		p_extension_funcs->reference_func, // GDExtensionClassReference reference_func;
@@ -358,6 +359,7 @@ void GDExtension::_register_extension_class_internal(GDExtensionClassLibraryPtr
 	extension->gdextension.free_property_list = p_extension_funcs->free_property_list_func;
 	extension->gdextension.property_can_revert = p_extension_funcs->property_can_revert_func;
 	extension->gdextension.property_get_revert = p_extension_funcs->property_get_revert_func;
+	extension->gdextension.validate_property = p_extension_funcs->validate_property_func;
 #ifndef DISABLE_DEPRECATED
 	if (p_deprecated_funcs) {
 		extension->gdextension.notification = p_deprecated_funcs->notification_func;
diff --git a/core/extension/gdextension_interface.h b/core/extension/gdextension_interface.h
index 4379e520b7..e104577c10 100644
--- a/core/extension/gdextension_interface.h
+++ b/core/extension/gdextension_interface.h
@@ -258,6 +258,7 @@ typedef const GDExtensionPropertyInfo *(*GDExtensionClassGetPropertyList)(GDExte
 typedef void (*GDExtensionClassFreePropertyList)(GDExtensionClassInstancePtr p_instance, const GDExtensionPropertyInfo *p_list);
 typedef GDExtensionBool (*GDExtensionClassPropertyCanRevert)(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name);
 typedef GDExtensionBool (*GDExtensionClassPropertyGetRevert)(GDExtensionClassInstancePtr p_instance, GDExtensionConstStringNamePtr p_name, GDExtensionVariantPtr r_ret);
+typedef GDExtensionBool (*GDExtensionClassValidateProperty)(GDExtensionClassInstancePtr p_instance, GDExtensionPropertyInfo *p_property);
 typedef void (*GDExtensionClassNotification)(GDExtensionClassInstancePtr p_instance, int32_t p_what); // Deprecated. Use GDExtensionClassNotification2 instead.
 typedef void (*GDExtensionClassNotification2)(GDExtensionClassInstancePtr p_instance, int32_t p_what, GDExtensionBool p_reversed);
 typedef void (*GDExtensionClassToString)(GDExtensionClassInstancePtr p_instance, GDExtensionBool *r_is_valid, GDExtensionStringPtr p_out);
@@ -297,6 +298,7 @@ typedef struct {
 	GDExtensionClassFreePropertyList free_property_list_func;
 	GDExtensionClassPropertyCanRevert property_can_revert_func;
 	GDExtensionClassPropertyGetRevert property_get_revert_func;
+	GDExtensionClassValidateProperty validate_property_func;
 	GDExtensionClassNotification2 notification_func;
 	GDExtensionClassToString to_string_func;
 	GDExtensionClassReference reference_func;
diff --git a/core/object/object.cpp b/core/object/object.cpp
index 0a0953f7dc..50026fc266 100644
--- a/core/object/object.cpp
+++ b/core/object/object.cpp
@@ -527,6 +527,27 @@ void Object::get_property_list(List<PropertyInfo> *p_list, bool p_reversed) cons
 void Object::validate_property(PropertyInfo &p_property) const {
 	_validate_propertyv(p_property);
 
+	if (_extension && _extension->validate_property) {
+		// GDExtension uses a StringName rather than a String for property name.
+		StringName prop_name = p_property.name;
+		GDExtensionPropertyInfo gdext_prop = {
+			(GDExtensionVariantType)p_property.type,
+			&prop_name,
+			&p_property.class_name,
+			(uint32_t)p_property.hint,
+			&p_property.hint_string,
+			p_property.usage,
+		};
+		if (_extension->validate_property(_extension_instance, &gdext_prop)) {
+			p_property.type = (Variant::Type)gdext_prop.type;
+			p_property.name = *reinterpret_cast<StringName *>(gdext_prop.name);
+			p_property.class_name = *reinterpret_cast<StringName *>(gdext_prop.class_name);
+			p_property.hint = (PropertyHint)gdext_prop.hint;
+			p_property.hint_string = *reinterpret_cast<String *>(gdext_prop.hint_string);
+			p_property.usage = gdext_prop.usage;
+		};
+	}
+
 	if (script_instance) { // Call it last to allow user altering already validated properties.
 		script_instance->validate_property(p_property);
 	}
diff --git a/core/object/object.h b/core/object/object.h
index 309cd34c4b..d50e3ec4ff 100644
--- a/core/object/object.h
+++ b/core/object/object.h
@@ -321,6 +321,7 @@ struct ObjectGDExtension {
 	GDExtensionClassFreePropertyList free_property_list;
 	GDExtensionClassPropertyCanRevert property_can_revert;
 	GDExtensionClassPropertyGetRevert property_get_revert;
+	GDExtensionClassValidateProperty validate_property;
 #ifndef DISABLE_DEPRECATED
 	GDExtensionClassNotification notification;
 #endif // DISABLE_DEPRECATED
diff --git a/core/object/script_language_extension.h b/core/object/script_language_extension.h
index c7218d99a6..e06f005320 100644
--- a/core/object/script_language_extension.h
+++ b/core/object/script_language_extension.h
@@ -689,9 +689,11 @@ public:
 	}
 	virtual void validate_property(PropertyInfo &p_property) const override {
 		if (native_info->validate_property_func) {
+			// GDExtension uses a StringName rather than a String for property name.
+			StringName prop_name = p_property.name;
 			GDExtensionPropertyInfo gdext_prop = {
 				(GDExtensionVariantType)p_property.type,
-				&p_property.name,
+				&prop_name,
 				&p_property.class_name,
 				(uint32_t)p_property.hint,
 				&p_property.hint_string,