From 5d301b44b948da336435c458245766709b6d2042 Mon Sep 17 00:00:00 2001
From: Takeshi KOMIYA <i.tkomiya@gmail.com>
Date: Sat, 1 Aug 2020 22:23:33 +0900
Subject: [PATCH] Fix #8032: autodoc: A typehint for inherited ivars is not
 shown

This tries to import the parent object for the instance attribute
to get type annotations for the variable.
---
 CHANGES                                           |  2 ++
 sphinx/ext/autodoc/__init__.py                    | 11 +++++++++++
 tests/roots/test-ext-autodoc/target/typed_vars.py |  4 ++++
 tests/test_ext_autodoc.py                         | 14 ++++++++++++++
 4 files changed, 31 insertions(+)

diff --git a/CHANGES b/CHANGES
index 59551371fad..11f063b3da3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -61,6 +61,8 @@ Bugs fixed
 * #7983: autodoc: Generator type annotation is wrongly rendered in py36
 * #8030: autodoc: An uninitialized annotated instance variable is not documented
   when ``:inherited-members:`` option given
+* #8032: autodoc: A type hint for the instance variable defined at parent class
+  is not shown in the document of the derived class
 * #7839: autosummary: cannot handle umlauts in function names
 * #7865: autosummary: Failed to extract summary line when abbreviations found
 * #7866: autosummary: Failed to extract correct summary line when docstring
diff --git a/sphinx/ext/autodoc/__init__.py b/sphinx/ext/autodoc/__init__.py
index 554997ff750..f3d516c58f5 100644
--- a/sphinx/ext/autodoc/__init__.py
+++ b/sphinx/ext/autodoc/__init__.py
@@ -2020,11 +2020,22 @@ def can_document_member(cls, member: Any, membername: str, isattr: bool, parent:
                 isattr and
                 member is INSTANCEATTR)
 
+    def import_parent(self) -> Any:
+        try:
+            parent = importlib.import_module(self.modname)
+            for name in self.objpath[:-1]:
+                parent = self.get_attr(parent, name)
+
+            return parent
+        except (ImportError, AttributeError):
+            return None
+
     def import_object(self, raiseerror: bool = False) -> bool:
         """Never import anything."""
         # disguise as an attribute
         self.objtype = 'attribute'
         self.object = INSTANCEATTR
+        self.parent = self.import_parent()
         self._datadescriptor = False
         return True
 
diff --git a/tests/roots/test-ext-autodoc/target/typed_vars.py b/tests/roots/test-ext-autodoc/target/typed_vars.py
index 65302fa44b5..43c58deb05b 100644
--- a/tests/roots/test-ext-autodoc/target/typed_vars.py
+++ b/tests/roots/test-ext-autodoc/target/typed_vars.py
@@ -25,3 +25,7 @@ def __init__(self):
         self.attr5: int         #: attr5
         self.attr6 = 0          # type: int
         """attr6"""
+
+
+class Derived(Class):
+    pass
diff --git a/tests/test_ext_autodoc.py b/tests/test_ext_autodoc.py
index be46c1490fb..8fa61e044e8 100644
--- a/tests/test_ext_autodoc.py
+++ b/tests/test_ext_autodoc.py
@@ -1576,6 +1576,20 @@ def test_autodoc_typed_instance_variables(app):
         '      This is descr4',
         '',
         '',
+        '.. py:class:: Derived()',
+        '   :module: target.typed_vars',
+        '',
+        '',
+        '   .. py:attribute:: Derived.attr2',
+        '      :module: target.typed_vars',
+        '      :type: int',
+        '',
+        '',
+        '   .. py:attribute:: Derived.descr4',
+        '      :module: target.typed_vars',
+        '      :type: int',
+        '',
+        '',
         '.. py:data:: attr1',
         '   :module: target.typed_vars',
         '   :type: str',