Fix from SF #681367: inherit tp_as_buffer. This only applies to C

types -- Python types already inherited this.

Misc/NEWS

@@ -258,6 +258,10 @@ Build
 C API
 -----
 
+- A C type that inherits from a base type that defines tp_as_buffer
+  will now inherit the tp_as_buffer pointer if it doesn't define one.
+  (SF #681367)
+
 - The PyArg_Parse functions now issue a DeprecationWarning if a float
   argument is provided when an integer is specified (this affects the 'b',
   'B', 'h', 'H', 'i', and 'l' codes).  Future versions of Python will

Objects/typeobject.c

@@ -2915,6 +2915,8 @@ PyType_Ready(PyTypeObject *type)
 			type->tp_as_sequence = base->tp_as_sequence;
 		if (type->tp_as_mapping == NULL)
 			type->tp_as_mapping = base->tp_as_mapping;
+		if (type->tp_as_buffer == NULL)
+			type->tp_as_buffer = base->tp_as_buffer;
 	}
 
 	/* Link into each base class's list of subclasses */