5 files changed, 75 insertions, 10 deletions
diff --git a/Lib/test/mock_socket.py b/Lib/test/mock_socket.py
index 8ef0ec8c8d..e36724f54b 100644
--- a/Lib/test/mock_socket.py
+++ b/Lib/test/mock_socket.py
@@ -21,8 +21,13 @@ class MockFile:
     """
     def __init__(self, lines):
         self.lines = lines
-    def readline(self):
-        return self.lines.pop(0) + b'\r\n'
+    def readline(self, limit=-1):
+        result = self.lines.pop(0) + b'\r\n'
+        if limit >= 0:
+            # Re-insert the line, removing the \r\n we added.
+            self.lines.insert(0, result[limit:-2])
+            result = result[:limit]
+        return result
     def close(self):
         pass
 
diff --git a/Lib/test/test_asyncio/test_events.py b/Lib/test/test_asyncio/test_events.py
index e6a1c97955..3f99da4c98 100644
--- a/Lib/test/test_asyncio/test_events.py
+++ b/Lib/test/test_asyncio/test_events.py
@@ -1176,15 +1176,17 @@ class EventLoopTestsMixin:
             loop = self.loop
             yield from asyncio.sleep(1e-2, loop=loop)
             yield from asyncio.sleep(1e-4, loop=loop)
+            yield from asyncio.sleep(1e-6, loop=loop)
+            yield from asyncio.sleep(1e-8, loop=loop)
+            yield from asyncio.sleep(1e-10, loop=loop)
 
         self.loop.run_until_complete(wait())
-        # The ideal number of call is 6, but on some platforms, the selector
+        # The ideal number of call is 12, but on some platforms, the selector
         # may sleep at little bit less than timeout depending on the resolution
-        # of the clock used by the kernel. Tolerate 2 useless calls on these
-        # platforms.
-        self.assertLessEqual(self.loop._run_once_counter, 8,
-            {'time_info': time.get_clock_info('time'),
-             'monotonic_info': time.get_clock_info('monotonic'),
+        # of the clock used by the kernel. Tolerate a few useless calls on
+        # these platforms.
+        self.assertLessEqual(self.loop._run_once_counter, 20,
+            {'clock_resolution': self.loop._clock_resolution,
              'selector': self.loop._selector.__class__.__name__})
 
 
diff --git a/Lib/test/test_builtin.py b/Lib/test/test_builtin.py
index 68430660f0..c078b443c5 100644
--- a/Lib/test/test_builtin.py
+++ b/Lib/test/test_builtin.py
@@ -16,6 +16,7 @@ import unittest
 import warnings
 from operator import neg
 from test.support import TESTFN, unlink,  run_unittest, check_warnings
+from test.script_helper import assert_python_ok
 try:
     import pty, signal
 except ImportError:
@@ -1592,6 +1593,34 @@ class TestSorted(unittest.TestCase):
         data = 'The quick Brown fox Jumped over The lazy Dog'.split()
         self.assertRaises(TypeError, sorted, data, None, lambda x,y: 0)
 
+
+class ShutdownTest(unittest.TestCase):
+
+    def test_cleanup(self):
+        # Issue #19255: builtins are still available at shutdown
+        code = """if 1:
+            import builtins
+            import sys
+
+            class C:
+                def __del__(self):
+                    print("before")
+                    # Check that builtins still exist
+                    len(())
+                    print("after")
+
+            c = C()
+            # Make this module survive until builtins and sys are cleaned
+            builtins.here = sys.modules[__name__]
+            sys.here = sys.modules[__name__]
+            # Create a reference loop so that this module needs to go
+            # through a GC phase.
+            here = sys.modules[__name__]
+            """
+        rc, out, err = assert_python_ok("-c", code)
+        self.assertEqual(["before", "after"], out.decode().splitlines())
+
+
 def load_tests(loader, tests, pattern):
     from doctest import DocTestSuite
     tests.addTest(DocTestSuite(builtins))
diff --git a/Lib/test/test_io.py b/Lib/test/test_io.py
index 23edee69ed..4182da3aae 100644
--- a/Lib/test/test_io.py
+++ b/Lib/test/test_io.py
@@ -2691,7 +2691,8 @@ class CTextIOWrapperTest(TextIOWrapperTest):
 
 class PyTextIOWrapperTest(TextIOWrapperTest):
     io = pyio
-    shutdown_error = "LookupError: unknown encoding: ascii"
+    #shutdown_error = "LookupError: unknown encoding: ascii"
+    shutdown_error = "TypeError: 'NoneType' object is not iterable"
 
 
 class IncrementalNewlineDecoderTest(unittest.TestCase):
diff --git a/Lib/test/test_smtplib.py b/Lib/test/test_smtplib.py
index 39bf7ae3b4..3f7b9b4175 100644
--- a/Lib/test/test_smtplib.py
+++ b/Lib/test/test_smtplib.py
@@ -563,6 +563,33 @@ class BadHELOServerTests(unittest.TestCase):
                             HOST, self.port, 'localhost', 3)
 
 
+@unittest.skipUnless(threading, 'Threading required for this test.')
+class TooLongLineTests(unittest.TestCase):
+    respdata = b'250 OK' + (b'.' * smtplib._MAXLINE * 2) + b'\n'
+
+    def setUp(self):
+        self.old_stdout = sys.stdout
+        self.output = io.StringIO()
+        sys.stdout = self.output
+
+        self.evt = threading.Event()
+        self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        self.sock.settimeout(15)
+        self.port = support.bind_port(self.sock)
+        servargs = (self.evt, self.respdata, self.sock)
+        threading.Thread(target=server, args=servargs).start()
+        self.evt.wait()
+        self.evt.clear()
+
+    def tearDown(self):
+        self.evt.wait()
+        sys.stdout = self.old_stdout
+
+    def testLineTooLong(self):
+        self.assertRaises(smtplib.SMTPResponseException, smtplib.SMTP,
+                          HOST, self.port, 'localhost', 3)
+
+
 sim_users = {'Mr.A@somewhere.com':'John A',
              'Ms.B@xn--fo-fka.com':'Sally B',
              'Mrs.C@somewhereesle.com':'Ruth C',
@@ -888,7 +915,8 @@ class SMTPSimTests(unittest.TestCase):
 def test_main(verbose=None):
     support.run_unittest(GeneralTests, DebuggingServerTests,
                               NonConnectingTests,
-                              BadHELOServerTests, SMTPSimTests)
+                              BadHELOServerTests, SMTPSimTests,
+                              TooLongLineTests)
 
 if __name__ == '__main__':
     test_main()