From 028b4c2c14c01d7370fb028741a7da1030724347 Mon Sep 17 00:00:00 2001
From: Bas Schoenmaeckers <b.schoenmaeckers@zandersgroup.com>
Date: Mon, 11 May 2026 17:08:26 +0200
Subject: [PATCH 1/2] Fix `ctypes.py_object` handling

---
 crates/vm/src/stdlib/_ctypes/base.rs   | 14 ++++++++++++++
 crates/vm/src/stdlib/_ctypes/simple.rs | 11 +++++++++++
 2 files changed, 25 insertions(+)

diff --git a/crates/vm/src/stdlib/_ctypes/base.rs b/crates/vm/src/stdlib/_ctypes/base.rs
index 7d611c27b0..2bbf7abccf 100644
--- a/crates/vm/src/stdlib/_ctypes/base.rs
+++ b/crates/vm/src/stdlib/_ctypes/base.rs
@@ -2342,6 +2342,20 @@ pub(super) fn bytes_to_pyobject(
                 }
                 Ok(vm.ctx.new_int(val).into())
             }
+            "O" => {
+                // py_object: return Python object from pointer
+                let ptr = read_ptr_from_buffer(bytes);
+                if ptr == 0 {
+                    return Err(vm.new_value_error("PyObject is NULL"));
+                }
+                let raw_ptr = ptr as *mut crate::object::PyObject;
+                unsafe {
+                    let obj =
+                        crate::PyObjectRef::from_raw(core::ptr::NonNull::new_unchecked(raw_ptr));
+                    let obj = core::mem::ManuallyDrop::new(obj);
+                    Ok((*obj).clone())
+                }
+            }
             "u" => {
                 let val = if bytes.len() >= mem::size_of::<WideChar>() {
                     let wc = if mem::size_of::<WideChar>() == 2 {
diff --git a/crates/vm/src/stdlib/_ctypes/simple.rs b/crates/vm/src/stdlib/_ctypes/simple.rs
index 1dd2001335..f5e07ebc2e 100644
--- a/crates/vm/src/stdlib/_ctypes/simple.rs
+++ b/crates/vm/src/stdlib/_ctypes/simple.rs
@@ -466,6 +466,17 @@ impl PyCSimpleType {
                     }
                 }
             }
+            // py_object: pass any Python object as PyObject*
+            Some("O") => {
+                return Ok(CArgObject {
+                    tag: b'O',
+                    value: FfiArgValue::Pointer(value.get_id()),
+                    obj: value,
+                    size: 0,
+                    offset: 0,
+                }
+                .to_pyobject(vm));
+            }
             // c_bool
             Some("?") => {
                 let bool_val = value.is_true(vm)?;

From 7639516f7315dcb0b1206da936574f5d672b3c70 Mon Sep 17 00:00:00 2001
From: Bas Schoenmaeckers <b.schoenmaeckers@zandersgroup.com>
Date: Mon, 11 May 2026 17:42:17 +0200
Subject: [PATCH 2/2] Assume owned pointer

---
 crates/vm/src/stdlib/_ctypes/base.rs | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/crates/vm/src/stdlib/_ctypes/base.rs b/crates/vm/src/stdlib/_ctypes/base.rs
index 2bbf7abccf..afc03213b2 100644
--- a/crates/vm/src/stdlib/_ctypes/base.rs
+++ b/crates/vm/src/stdlib/_ctypes/base.rs
@@ -2348,12 +2348,10 @@ pub(super) fn bytes_to_pyobject(
                 if ptr == 0 {
                     return Err(vm.new_value_error("PyObject is NULL"));
                 }
-                let raw_ptr = ptr as *mut crate::object::PyObject;
                 unsafe {
                     let obj =
-                        crate::PyObjectRef::from_raw(core::ptr::NonNull::new_unchecked(raw_ptr));
-                    let obj = core::mem::ManuallyDrop::new(obj);
-                    Ok((*obj).clone())
+                        PyObjectRef::from_raw(core::ptr::NonNull::new_unchecked(ptr as *mut _));
+                    Ok(obj)
                 }
             }
             "u" => {