Fix #9879: autodoc: AttributeError for object having invalid __doc__

1 files changed, 9 insertions, 2 deletions

diff --git a/sphinx/util/inspect.py b/sphinx/util/inspect.py
index 3a39bde1d..24ea49ae0 100644
--- a/sphinx/util/inspect.py
+++ b/sphinx/util/inspect.py
@@ -871,6 +871,13 @@ def getdoc(obj: Any, attrgetter: Callable = safe_getattr,
     * inherited docstring
     * inherited decorated methods
     """
+    def getdoc_internal(obj: Any, attrgetter: Callable = safe_getattr) -> Optional[str]:
+        doc = attrgetter(obj, '__doc__', None)
+        if isinstance(doc, str):
+            return doc
+        else:
+            return None
+
     if cls and name and isclassmethod(obj, cls, name):
         for basecls in getmro(cls):
             meth = basecls.__dict__.get(name)
@@ -879,7 +886,7 @@ def getdoc(obj: Any, attrgetter: Callable = safe_getattr,
                 if doc is not None or not allow_inherited:
                     return doc
 
-    doc = attrgetter(obj, '__doc__', None)
+    doc = getdoc_internal(obj)
     if ispartial(obj) and doc == obj.__class__.__doc__:
         return getdoc(obj.func)
     elif doc is None and allow_inherited:
@@ -888,7 +895,7 @@ def getdoc(obj: Any, attrgetter: Callable = safe_getattr,
             for basecls in getmro(cls):
                 meth = safe_getattr(basecls, name, None)
                 if meth is not None:
-                    doc = attrgetter(meth, '__doc__', None)
+                    doc = getdoc_internal(meth)
                     if doc is not None:
                         break