Add test for 'PyErr::set_context'

Author: bschoenmaeckers

src/err/err_state.rs

@@ -13,7 +13,7 @@ use crate::{
     ffi,
     ffi_ptr_ext::FfiPtrExt,
     types::{PyAnyMethods, PyTraceback, PyType},
-    Bound, BoundObject, Py, PyAny, PyErrArguments, PyTypeInfo, Python,
+    Bound, Py, PyAny, PyErrArguments, PyTypeInfo, Python,
 };
 
 pub(crate) struct PyErrState {
@@ -205,10 +205,8 @@ impl PyErrStateNormalized {
     }
 
     #[cfg_attr(not(Py_3_12), allow(unused))]
-    pub(crate) fn set_context(&self, py: Python<'_>, context: Option<Bound<'_, PyBaseException>>) {
-        let context = context
-            .map(Bound::into_ptr)
-            .unwrap_or_else(|| crate::types::PyNone::get(py).into_ptr());
+    pub(crate) fn set_context(&self, _py: Python<'_>, context: Option<Bound<'_, PyBaseException>>) {
+        let context = context.map(Bound::into_ptr).unwrap_or(std::ptr::null_mut());
 
         unsafe { ffi::PyException_SetContext(self.pvalue.as_ptr(), context) };
     }

src/err/mod.rs

@@ -618,11 +618,11 @@ impl PyErr {
     /// Set the context associated with the exception, pass `None` to clear it.
     pub fn set_context(&self, py: Python<'_>, context: Option<PyErr>) {
         let value = self.value(py);
-        let cause = context.map(|err| err.into_value(py));
+        let context = context.map(|err| err.into_value(py));
         unsafe {
             ffi::PyException_SetContext(
                 value.as_ptr(),
-                cause.map_or(std::ptr::null_mut(), Py::into_ptr),
+                context.map_or(std::ptr::null_mut(), Py::into_ptr),
             );
         }
     }
@@ -1050,4 +1050,19 @@ mod tests {
             );
         });
     }
+
+    #[test]
+    fn test_set_context() {
+        Python::attach(|py| {
+            let err = PyErr::new::<PyValueError, _>("original error");
+            assert!(err.context(py).is_none());
+
+            let context = PyErr::new::<PyTypeError, _>("context error");
+            err.set_context(py, Some(context));
+            assert!(err.context(py).unwrap().is_instance_of::<PyTypeError>(py));
+
+            err.set_context(py, None);
+            assert!(err.context(py).is_none());
+        })
+    }
 }