stop suppressing unrelated exceptions in PyAny::hasattr

newsfragments/3271.fixed.md

@@ -0,0 +1 @@
+Stop suppressing unrelated exceptions in `PyAny::hasattr`.

src/types/any.rs

@@ -1,7 +1,7 @@
 use crate::class::basic::CompareOp;
 use crate::conversion::{AsPyPointer, FromPyObject, IntoPy, IntoPyPointer, PyTryFrom, ToPyObject};
 use crate::err::{PyDowncastError, PyErr, PyResult};
-use crate::exceptions::PyTypeError;
+use crate::exceptions::{PyAttributeError, PyTypeError};
 use crate::type_object::PyTypeInfo;
 #[cfg(not(PyPy))]
 use crate::types::PySuper;
@@ -83,10 +83,24 @@ impl PyAny {
     where
         N: IntoPy<Py<PyString>>,
     {
-        let py = self.py();
-        let attr_name = attr_name.into_py(py);
+        // PyObject_HasAttr suppresses all exceptions, which was the behaviour of `hasattr` in Python 2.
+        // Use an implementation which suppresses only AttributeError, which is consistent with `hasattr` in Python 3.
+        self.hasattr_impl(attr_name.into_py(self.py()))
+    }
 
-        unsafe { Ok(ffi::PyObject_HasAttr(self.as_ptr(), attr_name.as_ptr()) != 0) }
+    fn hasattr_impl(&self, attr_name: Py<PyString>) -> PyResult<bool> {
+        let py = self.py();
+        let result = unsafe {
+            PyObject::from_owned_ptr_or_err(
+                py,
+                ffi::PyObject_GetItem(self.as_ptr(), attr_name.as_ptr()),
+            )
+        };
+        match result {
+            Ok(_) => Ok(true),
+            Err(err) if err.is_instance_of::<PyAttributeError>(py) => Ok(false),
+            Err(e) => Err(e),
+        }
     }
 
     /// Retrieves an attribute value.