fix: memory leak in Option<T>::as_ptr

CHANGELOG.md

@@ -84,6 +84,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix panic in `#[pyfunction]` generated code when a required argument following an `Option` was not provided.  [#2093](https://github.com/PyO3/pyo3/pull/2093)
 - Fixed undefined behaviour caused by incorrect `ExactSizeIterator` implementations. [#2124](https://github.com/PyO3/pyo3/pull/2124)
 - Add missing FFI definitions `_PyLong_NumBits` and `_PyLong_AsByteArray` on PyPy. [#2146](https://github.com/PyO3/pyo3/pull/2146)
+- Fix memory leak in implementation of `AsPyPointer` for `Option<T>`. [#2160](https://github.com/PyO3/pyo3/pull/2160)
 
 ## [0.15.1] - 2021-11-19
 

src/conversion.rs

@@ -44,7 +44,7 @@ where
     #[inline]
     fn as_ptr(&self) -> *mut ffi::PyObject {
         self.as_ref()
-            .map_or_else(std::ptr::null_mut, |t| t.into_ptr())
+            .map_or_else(std::ptr::null_mut, |t| t.as_ptr())
     }
 }
 
@@ -555,7 +555,7 @@ where
 #[cfg(test)]
 mod tests {
     use crate::types::{IntoPyDict, PyAny, PyDict, PyList};
-    use crate::{Python, ToPyObject};
+    use crate::{AsPyPointer, PyObject, Python, ToPyObject};
 
     use super::PyTryFrom;
 
@@ -595,4 +595,21 @@ mod tests {
             assert_eq!(list, val);
         });
     }
+
+    #[test]
+    fn test_option_as_ptr() {
+        Python::with_gil(|py| {
+            let mut option: Option<PyObject> = None;
+            assert_eq!(option.as_ptr(), std::ptr::null_mut());
+
+            let none = py.None();
+            option = Some(none.clone());
+
+            let ref_cnt = none.get_refcnt(py);
+            assert_eq!(option.as_ptr(), none.as_ptr());
+
+            // Ensure ref count not changed by as_ptr call
+            assert_eq!(none.get_refcnt(py), ref_cnt);
+        });
+    }
 }