PYTHON-1867 Fix noisy AttributeError in Cursor.__del__ (#421)

Author: arthurdarcet

pymongo/cursor.py

@@ -291,7 +291,12 @@ def _clone_base(self, session):
     def __die(self, synchronous=False):
         """Closes this cursor.
         """
-        already_killed = self.__killed
+        try:
+            already_killed = self.__killed
+        except AttributeError:
+            # __init__ did not run to completion (or at all).
+            return
+
         self.__killed = True
         if self.__id and not already_killed:
             if self.__exhaust and self.__exhaust_mgr:

test/test_cursor.py

@@ -35,7 +35,7 @@
                      ALL,
                      OFF)
 from pymongo.collation import Collation
-from pymongo.cursor import CursorType
+from pymongo.cursor import Cursor, CursorType
 from pymongo.errors import (ConfigurationError,
                             ExecutionTimeout,
                             InvalidOperation,
@@ -1409,6 +1409,12 @@ def assertCursorKilled():
         else:
             self.assertEqual(0, len(results["started"]))
 
+    def test_delete_not_initialized(self):
+        # Creating a cursor with invalid arguments will not run __init__
+        # but will still call __del__, eg test.find(invalidKwarg=1).
+        cursor = Cursor.__new__(Cursor)  # Skip calling __init__
+        cursor.__del__()  # no error
+
 
 class TestRawBatchCursor(IntegrationTest):
     def test_find_raw(self):