ffi: fix segfault in _GET_TZINFO methods

CHANGELOG.md

@@ -12,6 +12,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Default to "m" ABI tag when choosing `libpython` link name for CPython 3.7 on Unix. [#2288](https://github.com/PyO3/pyo3/pull/2288)
 
+### Fixed
+
+- Fix segfault when calling FFI methods `PyDateTime_DATE_GET_TZINFO` or `PyDateTime_TIME_GET_TZINFO` on `datetime` or `time` without a tzinfo. [#2289](https://github.com/PyO3/pyo3/pull/2289)
+
 ## [0.16.3] - 2022-04-05
 
 ### Packaging

pyo3-ffi/src/datetime.rs

@@ -155,7 +155,11 @@ macro_rules! _PyDateTime_GET_FOLD {
 #[cfg(not(PyPy))]
 macro_rules! _PyDateTime_GET_TZINFO {
     ($o: expr) => {
-        (*$o).tzinfo
+        if (*$o).hastzinfo != 0 {
+            (*$o).tzinfo
+        } else {
+            $crate::Py_None()
+        }
     };
 }
 

src/ffi/tests.rs

@@ -180,3 +180,44 @@ fn ucs4() {
         }
     })
 }
+
+#[test]
+#[cfg(not(PyPy))]
+fn test_get_tzinfo() {
+    crate::Python::with_gil(|py| {
+        use crate::types::{PyDateTime, PyTime};
+        use crate::{AsPyPointer, PyAny, ToPyObject};
+
+        let datetime = py.import("datetime").map_err(|e| e.print(py)).unwrap();
+        let timezone = datetime.getattr("timezone").unwrap();
+        let utc = timezone.getattr("utc").unwrap().to_object(py);
+
+        let dt = PyDateTime::new(py, 2018, 1, 1, 0, 0, 0, 0, Some(&utc)).unwrap();
+
+        assert!(
+            unsafe { py.from_borrowed_ptr::<PyAny>(PyDateTime_DATE_GET_TZINFO(dt.as_ptr())) }
+                .is(&utc)
+        );
+
+        let dt = PyDateTime::new(py, 2018, 1, 1, 0, 0, 0, 0, None).unwrap();
+
+        assert!(
+            unsafe { py.from_borrowed_ptr::<PyAny>(PyDateTime_DATE_GET_TZINFO(dt.as_ptr())) }
+                .is_none()
+        );
+
+        let t = PyTime::new(py, 0, 0, 0, 0, Some(&utc)).unwrap();
+
+        assert!(
+            unsafe { py.from_borrowed_ptr::<PyAny>(PyDateTime_TIME_GET_TZINFO(t.as_ptr())) }
+                .is(&utc)
+        );
+
+        let t = PyTime::new(py, 0, 0, 0, 0, None).unwrap();
+
+        assert!(
+            unsafe { py.from_borrowed_ptr::<PyAny>(PyDateTime_TIME_GET_TZINFO(t.as_ptr())) }
+                .is_none()
+        );
+    })
+}