Fix #6588: autodoc: Decorated inherited method has no documentation

1 files changed, 12 insertions, 1 deletions

diff --git a/sphinx/util/inspect.py b/sphinx/util/inspect.py
index 0434d7850..38777728a 100644
--- a/sphinx/util/inspect.py
+++ b/sphinx/util/inspect.py
@@ -691,13 +691,14 @@ class Signature:
 
 
 def getdoc(obj: Any, attrgetter: Callable = safe_getattr,
-           allow_inherited: bool = False) -> str:
+           allow_inherited: bool = False, cls: Any = None, name: str = None) -> str:
     """Get the docstring for the object.
 
     This tries to obtain the docstring for some kind of objects additionally:
 
     * partial functions
     * inherited docstring
+    * inherited decorated methods
     """
     doc = attrgetter(obj, '__doc__', None)
     if ispartial(obj) and doc == obj.__class__.__doc__:
@@ -705,4 +706,14 @@ def getdoc(obj: Any, attrgetter: Callable = safe_getattr,
     elif doc is None and allow_inherited:
         doc = inspect.getdoc(obj)
 
+        if doc is None and cls:
+            # inspect.getdoc() does not support some kind of inherited and decorated methods.
+            # This tries to obtain the docstring from super classes.
+            for basecls in getattr(cls, '__mro__', []):
+                meth = safe_getattr(basecls, name, None)
+                if meth:
+                    doc = inspect.getdoc(meth)
+                    if doc:
+                        break
+
     return doc