From ec1a563cee95435aad6758b71a0f4eb297ef2993 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 | 6 ++++++
 sphinx/util/typing.py  | 7 ++++++-
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/CHANGES b/CHANGES
index 22876d43b1c..126dd2fffd3 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 37997e6b275..228efd98106 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
@@ -302,6 +303,11 @@ def iscoroutinefunction(obj: Any) -> bool:
         return False
 
 
+def isiterable(obj: Any) -> bool:
+    """Check if the object is iterable."""
+    return isinstance(obj, collections.abc.Iterable)
+
+
 def isproperty(obj: Any) -> bool:
     """Check if the object is property."""
     if sys.version_info > (3, 8):
diff --git a/sphinx/util/typing.py b/sphinx/util/typing.py
index d71ca1b2d66..4f11a381839 100644
--- a/sphinx/util/typing.py
+++ b/sphinx/util/typing.py
@@ -105,7 +105,12 @@ def _stringify_py37(annotation: Any) -> str:
         return repr(annotation)
 
     if getattr(annotation, '__args__', None):
-        if qualname == 'Union':
+        from sphinx.util.inspect import isiterable
+
+        if not isiterable(annotation.__args__):
+            # 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])