Fixed #32114 -- Fixed parallel test crash on non-picklable objects in subtests.

django/test/testcases.py

@@ -1,6 +1,7 @@
 import difflib
 import json
 import logging
+import pickle
 import posixpath
 import sys
 import threading
@@ -92,6 +93,18 @@ def to_list(value):
     return value
 
 
+def is_pickable(obj):
+    """
+    Returns true if the object can be dumped and loaded through the pickle
+    module.
+    """
+    try:
+        pickle.loads(pickle.dumps(obj))
+    except (AttributeError, TypeError):
+        return False
+    return True
+
+
 def assert_and_parse_html(self, html, user_msg, msg):
     try:
         dom = parse_html(html)
@@ -303,6 +316,23 @@ class SimpleTestCase(unittest.TestCase):
         """
         self._setup_and_call(result)
 
+    def __getstate__(self):
+        """
+        Make SimpleTestCase picklable for parallel tests using subtests.
+        """
+        state = super().__dict__
+        # _outcome and _subtest cannot be tested on picklability, since they
+        # contain the TestCase itself, leading to an infinite recursion.
+        if state["_outcome"]:
+            pickable_state = {"_outcome": None, "_subtest": None}
+            for key, value in state.items():
+                if key in pickable_state or not is_pickable(value):
+                    continue
+                pickable_state[key] = value
+            return pickable_state
+
+        return state
+
     def debug(self):
         """Perform the same as __call__(), without catching the exception."""
         debug_result = _DebugResult()