Backport bugfixes from upstream 4.1.x branch for compatibility with Python 3.10-rc2

generate-correct-reference-to-parent-class.patch

@@ -0,0 +1,36 @@
+From d0c97e9eb57126e38b7b018a101df1ecb1ad12b8 Mon Sep 17 00:00:00 2001
+From: Takeshi KOMIYA <i.tkomiya@gmail.com>
+Date: Sat, 31 Jul 2021 01:41:35 +0900
+Subject: [PATCH] Fix #9504: autodoc: generate incorrect reference to the
+ parent class
+
+Autodoc generates incorrect references to the parent class the target
+class inherites the class having `_name` attribute.  It conciders the
+parent is a kind of SpecialForm'ed class by mistake.  This uses
+`isinstance(X, SpecialForm)` to check that.
+
+Note: SpecialForm became a class since Python 3.7.
+---
+ CHANGES               | 2 ++
+ sphinx/util/typing.py | 8 ++------
+ 2 files changed, 4 insertions(+), 6 deletions(-)
+
+diff --git a/sphinx/util/typing.py b/sphinx/util/typing.py
+index 012d32e524..f856950bf2 100644
+--- a/sphinx/util/typing.py
++++ b/sphinx/util/typing.py
+@@ -171,12 +171,8 @@ def _restify_py37(cls: Optional[Type]) -> str:
+             text += r"\ [%s]" % ", ".join(restify(a) for a in cls.__args__)
+ 
+         return text
+-    elif hasattr(cls, '_name'):
+-        # SpecialForm
+-        if cls.__module__ == 'typing':
+-            return ':obj:`~%s.%s`' % (cls.__module__, cls._name)
+-        else:
+-            return ':obj:`%s.%s`' % (cls.__module__, cls._name)
++    elif isinstance(cls, typing._SpecialForm):
++        return ':obj:`~%s.%s`' % (cls.__module__, cls._name)
+     elif hasattr(cls, '__qualname__'):
+         if cls.__module__ == 'typing':
+             return ':class:`~%s.%s`' % (cls.__module__, cls.__qualname__)