From cd2232eddf82d609e3d2de39011c4a6a6fdafe57 Mon Sep 17 00:00:00 2001
From: Marc Gilleron <marc.gilleron@gmail.com>
Date: Fri, 23 Sep 2022 21:20:37 +0100
Subject: [PATCH] Fix passing null to functions taking Object parameters

---
 binding_generator.py | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/binding_generator.py b/binding_generator.py
index c1e2a69..6294fd5 100644
--- a/binding_generator.py
+++ b/binding_generator.py
@@ -1587,7 +1587,9 @@ def get_encoded_arg(arg_name, type_name, type_meta):
         result.append(f"\tPtrToArg<{correct_type(type_name)}>::encode({name}, &{name}_encoded);")
         name = f"&{name}_encoded"
     elif is_engine_class(type_name):
-        name = f"{name}->_owner"
+        # `{name}` is a C++ wrapper, it contains a field which is the object's pointer Godot expects.
+        # We have to check `nullptr` because when the caller sends `nullptr`, the wrapper itself will be null.
+        name = f"({name} != nullptr ? {name}->_owner : nullptr)"
     else:
         name = f"&{name}"