From 33cef6918ff9fc6074e54899504a59c3aa132bf3 Mon Sep 17 00:00:00 2001
From: Dennis Sweeney <36520290+sweeneyde@users.noreply.github.com>
Date: Thu, 28 Oct 2021 06:11:18 -0400
Subject: [PATCH] [3.9] bpo-30570: Fix segfault on buildbots caused by stack
 overflow from recursion in tests (GH-29258)

* Don't stackoveflow on debug builds

* Also catch the pickletester case.
(cherry picked from commit d56375a0dd4cee162081b173310298a3d32af293)

Co-authored-by: Dennis Sweeney <36520290+sweeneyde@users.noreply.github.com>
---
 Lib/test/pickletester.py    |  3 ++-
 Lib/test/test_isinstance.py | 27 ++++++++++++++++-----------
 2 files changed, 18 insertions(+), 12 deletions(-)

diff --git a/Lib/test/pickletester.py b/Lib/test/pickletester.py
index e86847c5f13d84..4684c9e68994b0 100644
--- a/Lib/test/pickletester.py
+++ b/Lib/test/pickletester.py
@@ -2371,7 +2371,8 @@ def test_bad_getattr(self):
         # Issue #3514: crash when there is an infinite loop in __getattr__
         x = BadGetattr()
         for proto in protocols:
-            self.assertRaises(RuntimeError, self.dumps, x, proto)
+            with support.infinite_recursion():
+                self.assertRaises(RuntimeError, self.dumps, x, proto)
 
     def test_reduce_bad_iterator(self):
         # Issue4176: crash when 4th and 5th items of __reduce__()
diff --git a/Lib/test/test_isinstance.py b/Lib/test/test_isinstance.py
index 34082a1a4b3619..70dbe7166fd577 100644
--- a/Lib/test/test_isinstance.py
+++ b/Lib/test/test_isinstance.py
@@ -4,6 +4,7 @@
 
 import unittest
 import sys
+from test import support
 
 
 
@@ -244,12 +245,14 @@ def test_subclass_tuple(self):
     def test_subclass_recursion_limit(self):
         # make sure that issubclass raises RecursionError before the C stack is
         # blown
-        self.assertRaises(RecursionError, blowstack, issubclass, str, str)
+        with support.infinite_recursion():
+            self.assertRaises(RecursionError, blowstack, issubclass, str, str)
 
     def test_isinstance_recursion_limit(self):
         # make sure that issubclass raises RecursionError before the C stack is
         # blown
-        self.assertRaises(RecursionError, blowstack, isinstance, '', str)
+        with support.infinite_recursion():
+            self.assertRaises(RecursionError, blowstack, isinstance, '', str)
 
     def test_issubclass_refcount_handling(self):
         # bpo-39382: abstract_issubclass() didn't hold item reference while
@@ -276,19 +279,19 @@ class X:
             @property
             def __bases__(self):
                 return self.__bases__
-
-        self.assertRaises(RecursionError, issubclass, X(), int)
-        self.assertRaises(RecursionError, issubclass, int, X())
-        self.assertRaises(RecursionError, isinstance, 1, X())
+        with support.infinite_recursion():
+            self.assertRaises(RecursionError, issubclass, X(), int)
+            self.assertRaises(RecursionError, issubclass, int, X())
+            self.assertRaises(RecursionError, isinstance, 1, X())
 
     def test_infinite_recursion_via_bases_tuple(self):
         """Regression test for bpo-30570."""
         class Failure(object):
             def __getattr__(self, attr):
                 return (self, None)
-
-        with self.assertRaises(RecursionError):
-            issubclass(Failure(), int)
+        with support.infinite_recursion():
+            with self.assertRaises(RecursionError):
+                issubclass(Failure(), int)
 
     def test_infinite_cycle_in_bases(self):
         """Regression test for bpo-30570."""
@@ -296,7 +299,8 @@ class X:
             @property
             def __bases__(self):
                 return (self, self, self)
-        self.assertRaises(RecursionError, issubclass, X(), int)
+        with support.infinite_recursion():
+            self.assertRaises(RecursionError, issubclass, X(), int)
 
     def test_infinitely_many_bases(self):
         """Regression test for bpo-30570."""
@@ -309,7 +313,8 @@ class B:
                     pass
                 A.__getattr__ = B.__getattr__ = X.__getattr__
                 return (A(), B())
-        self.assertRaises(RecursionError, issubclass, X(), int)
+        with support.infinite_recursion():
+            self.assertRaises(RecursionError, issubclass, X(), int)
 
 
 def blowstack(fxn, arg, compare_to):