Fix unhandling of possible recursion error on `ExceptionRecord.__deepcopy__` (#870)

2 files changed, 27 insertions, 1 deletions

diff --git a/mobly/records.py b/mobly/records.py
index 38c992d..69f1f9d 100644
--- a/mobly/records.py
+++ b/mobly/records.py
@@ -277,7 +277,7 @@ class ExceptionRecord:
     """
     try:
       exception = copy.deepcopy(self.exception)
-    except TypeError:
+    except (TypeError, RecursionError):
       # If the exception object cannot be copied, use the original
       # exception object.
       exception = self.exception
diff --git a/tests/mobly/records_test.py b/tests/mobly/records_test.py
index 7b37a2f..ec6254d 100755
--- a/tests/mobly/records_test.py
+++ b/tests/mobly/records_test.py
@@ -36,6 +36,19 @@ class RecordTestError(Exception):
     self._something = something
 
 
+class RecordTestRecursiveError(Exception):
+  """Error class with self recursion.
+
+  Used for ExceptionRecord tests.
+  """
+
+  def __init__(self):
+    super().__init__(self)  # create a self recursion here.
+
+  def __str__(self):
+    return 'Oh ha!'
+
+
 class RecordsTest(unittest.TestCase):
   """This test class tests the implementation of classes in mobly.records.
   """
@@ -427,6 +440,19 @@ class RecordsTest(unittest.TestCase):
     self.assertDictEqual(er.to_dict(), new_er.to_dict())
     self.assertEqual(er.type, 'RecordTestError')
 
+  def test_recursive_exception_record_deepcopy(self):
+    """Makes sure ExceptionRecord wrapper handles deep copy properly in case of
+    recursive exception.
+    """
+    try:
+      raise RecordTestRecursiveError()
+    except RecordTestRecursiveError as e:
+      er = records.ExceptionRecord(e)
+    new_er = copy.deepcopy(er)
+    self.assertIsNot(er, new_er)
+    self.assertDictEqual(er.to_dict(), new_er.to_dict())
+    self.assertEqual(er.type, 'RecordTestRecursiveError')
+
   def test_add_controller_info_record(self):
     tr = records.TestResult()
     self.assertFalse(tr.controller_info)