[2.2.x] Fixed #30516 -- Fixed crash of autoreloader when re-raising exceptions with custom signature.

Regression in c8720e7696ca41f3262d5369365cc1bd72a216ca.

Backport of 0344565179527d80990e2247e3be7c04aa8c43c8 from master

3 files changed, 34 insertions, 1 deletions

diff --git a/django/utils/autoreload.py b/django/utils/autoreload.py
index ade9abdfdf..35952d5631 100644
--- a/django/utils/autoreload.py
+++ b/django/utils/autoreload.py
@@ -74,7 +74,7 @@ def check_errors(fn):
 def raise_last_exception():
     global _exception
     if _exception is not None:
-        raise _exception[0](_exception[1]).with_traceback(_exception[2])
+        raise _exception[1]
 
 
 def ensure_echo_on():
diff --git a/docs/releases/2.2.2.txt b/docs/releases/2.2.2.txt
index 08af175caa..e95fa343fc 100644
--- a/docs/releases/2.2.2.txt
+++ b/docs/releases/2.2.2.txt
@@ -25,3 +25,6 @@ Bugfixes
 * Fixed crash of :class:`~django.contrib.postgres.aggregates.ArrayAgg` and
   :class:`~django.contrib.postgres.aggregates.StringAgg` with ``ordering``
   argument when used in a ``Subquery`` (:ticket:`30315`).
+
+* Fixed a regression in Django 2.2 that caused a crash of auto-reloader when
+  an exception with custom signature is raised (:ticket:`30516`).
diff --git a/tests/utils_tests/test_autoreload.py b/tests/utils_tests/test_autoreload.py
index 9253482e7b..82f7287fa8 100644
--- a/tests/utils_tests/test_autoreload.py
+++ b/tests/utils_tests/test_autoreload.py
@@ -293,6 +293,36 @@ class TestRaiseLastException(SimpleTestCase):
             with self.assertRaisesMessage(MyException, 'Test Message'):
                 autoreload.raise_last_exception()
 
+    def test_raises_custom_exception(self):
+        class MyException(Exception):
+            def __init__(self, msg, extra_context):
+                super().__init__(msg)
+                self.extra_context = extra_context
+        # Create an exception.
+        try:
+            raise MyException('Test Message', 'extra context')
+        except MyException:
+            exc_info = sys.exc_info()
+
+        with mock.patch('django.utils.autoreload._exception', exc_info):
+            with self.assertRaisesMessage(MyException, 'Test Message'):
+                autoreload.raise_last_exception()
+
+    def test_raises_exception_with_context(self):
+        try:
+            raise Exception(2)
+        except Exception as e:
+            try:
+                raise Exception(1) from e
+            except Exception:
+                exc_info = sys.exc_info()
+
+        with mock.patch('django.utils.autoreload._exception', exc_info):
+            with self.assertRaises(Exception) as cm:
+                autoreload.raise_last_exception()
+            self.assertEqual(cm.exception.args[0], 1)
+            self.assertEqual(cm.exception.__cause__.args[0], 2)
+
 
 class RestartWithReloaderTests(SimpleTestCase):
     executable = '/usr/bin/python'