From 2ad381f6951e866ec5f71bb5f0875def23b34987 Mon Sep 17 00:00:00 2001
From: Ivan Levkivskyi <levkivskyi@gmail.com>
Date: Fri, 24 Feb 2017 04:03:28 +0100
Subject: [PATCH 1/2] Update to typing: treat subscripted generics as proxies
 (#265)

(cherry picked from commit abb3b8ad94d699c8560d94ee9bac9c917b382abe)
---
 Lib/test/test_typing.py | 27 +++++++++++++++++++++++++++
 Lib/typing.py           |  7 +++++++
 2 files changed, 34 insertions(+)

diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 64d8276658ee7f..3a82b595da5950 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -674,6 +674,33 @@ class C(B[int]):
         c.bar = 'abc'
         self.assertEqual(c.__dict__, {'bar': 'abc'})
 
+    def test_subscripted_generics_as_proxies(self):
+        T = TypeVar('T')
+        class C(Generic[T]):
+            x = 'def'
+        self.assertEqual(C[int].x, 'def')
+        self.assertEqual(C[C[int]].x, 'def')
+        C[C[int]].x = 'changed'
+        self.assertEqual(C.x, 'changed')
+        self.assertEqual(C[str].x, 'changed')
+        C[List[str]].z = 'new'
+        self.assertEqual(C.z, 'new')
+        self.assertEqual(C[Tuple[int]].z, 'new')
+
+        self.assertEqual(C().x, 'changed')
+        self.assertEqual(C[Tuple[str]]().z, 'new')
+
+        class D(C[T]):
+            pass
+        self.assertEqual(D[int].x, 'changed')
+        self.assertEqual(D.z, 'new')
+        D.z = 'from derived z'
+        D[int].x = 'from derived x'
+        self.assertEqual(C.x, 'changed')
+        self.assertEqual(C[int].z, 'new')
+        self.assertEqual(D.x, 'from derived x')
+        self.assertEqual(D[str].z, 'from derived z')
+
     def test_false_subclasses(self):
         class MyMapping(MutableMapping[str, str]): pass
         self.assertNotIsInstance({}, MyMapping)
diff --git a/Lib/typing.py b/Lib/typing.py
index efe358faf20988..fc2ed94cffd656 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -1158,6 +1158,13 @@ def __copy__(self):
                               self.__parameters__, self.__args__, self.__origin__,
                               self.__extra__, self.__orig_bases__)
 
+    def __setattr__(self, attr, value):
+        # We consider all the subscripted genrics as proxies for original class
+        if attr.startswith('__') and attr.endswith('__'):
+            super(GenericMeta, self).__setattr__(attr, value)
+        else:
+            super(GenericMeta, _gorg(self)).__setattr__(attr, value)
+
 
 # Prevent checks for Generic to crash when defining Generic.
 Generic = None

From 8128d0dfee176e45b816e38b9950206517d2d829 Mon Sep 17 00:00:00 2001
From: Ivan Levkivskyi <levkivskyi@gmail.com>
Date: Fri, 24 Feb 2017 18:28:26 +0100
Subject: [PATCH 2/2] bpo-28556: Fix regression that sneaked into recent typing
 updates (GH-270)

(cherry picked from commit 365cb5bb9069273e6970c9d5d17ee2fe5003e7ac)
---
 Lib/test/test_typing.py | 8 ++++++++
 Lib/typing.py           | 5 ++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/Lib/test/test_typing.py b/Lib/test/test_typing.py
index 3a82b595da5950..f0070ec975791a 100644
--- a/Lib/test/test_typing.py
+++ b/Lib/test/test_typing.py
@@ -701,6 +701,14 @@ class D(C[T]):
         self.assertEqual(D.x, 'from derived x')
         self.assertEqual(D[str].z, 'from derived z')
 
+    def test_abc_registry_kept(self):
+        T = TypeVar('T')
+        class C(Generic[T]): ...
+        C.register(int)
+        self.assertIsInstance(1, C)
+        C[int]
+        self.assertIsInstance(1, C)
+
     def test_false_subclasses(self):
         class MyMapping(MutableMapping[str, str]): pass
         self.assertNotIsInstance({}, MyMapping)
diff --git a/Lib/typing.py b/Lib/typing.py
index fc2ed94cffd656..9a0f49099a3114 100644
--- a/Lib/typing.py
+++ b/Lib/typing.py
@@ -1160,7 +1160,10 @@ def __copy__(self):
 
     def __setattr__(self, attr, value):
         # We consider all the subscripted genrics as proxies for original class
-        if attr.startswith('__') and attr.endswith('__'):
+        if (
+            attr.startswith('__') and attr.endswith('__') or
+            attr.startswith('_abc_')
+        ):
             super(GenericMeta, self).__setattr__(attr, value)
         else:
             super(GenericMeta, _gorg(self)).__setattr__(attr, value)