From eee1557d894d8fd4484a263cb9fe00adad14cbc6 Mon Sep 17 00:00:00 2001
From: Takeshi KOMIYA <i.tkomiya@gmail.com>
Date: Sat, 3 Oct 2020 02:01:12 +0900
Subject: [PATCH] Fix #8157: autodoc: TypeError is raised when annotation has
 invalid __args__

Typically, the __args__ attribute of type annotations is a tuple
containing arguments for the types (ex. The __args__ of `List[int]` is
`(int,)`).  But some kind of types has non tuple __args__ attribute.
For example, `nptyping.NDArray` is one of them.

This fixes the TypeError when the invalid __args__ attribute found.
---
 CHANGES                | 1 +
 sphinx/util/inspect.py | 1 +
 sphinx/util/typing.py  | 5 ++++-
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index b82c2e948a8..e30d42e43a8 100644
--- a/CHANGES
+++ b/CHANGES
@@ -34,6 +34,7 @@ Bugs fixed
   by string not ending with blank lines
 * #8142: autodoc: Wrong constructor signature for the class derived from
   typing.Generic
+* #8157: autodoc: TypeError is raised when annotation has invalid __args__
 * #8192: napoleon: description is disappeared when it contains inline literals
 * #8142: napoleon: Potential of regex denial of service in google style docs
 * #8169: LaTeX: pxjahyper loaded even when latex_engine is not platex
diff --git a/sphinx/util/inspect.py b/sphinx/util/inspect.py
index 378174993f3..4a608afe822 100644
--- a/sphinx/util/inspect.py
+++ b/sphinx/util/inspect.py
@@ -9,6 +9,7 @@
 """
 
 import builtins
+import collections.abc
 import contextlib
 import enum
 import inspect
diff --git a/sphinx/util/typing.py b/sphinx/util/typing.py
index 4dac3b6950f..d8d516f2386 100644
--- a/sphinx/util/typing.py
+++ b/sphinx/util/typing.py
@@ -109,7 +109,10 @@ def _stringify_py37(annotation: Any) -> str:
         return repr(annotation)
 
     if getattr(annotation, '__args__', None):
-        if qualname == 'Union':
+        if not isinstance(annotation.__args__, (list, tuple)):
+            # broken __args__ found
+            qualname = repr(annotation)
+        elif qualname == 'Union':
             if len(annotation.__args__) > 1 and annotation.__args__[-1] is NoneType:
                 if len(annotation.__args__) > 2:
                     args = ', '.join(stringify(a) for a in annotation.__args__[:-1])