Set __classcell__ if it exists

filmor · filmor · commit b17b9d3a0e0c · 2020-05-15T01:29:02.000+02:00
If `PyCell_Set` is not called with a cell it will raise an exception,
which is perfectly valid here.
diff --git a/src/runtime/runtime.cs b/src/runtime/runtime.cs
@@ -1966,6 +1966,15 @@ internal static IntPtr PyMem_Realloc(IntPtr ptr, long size)
         [DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
         internal static extern void PyErr_Print();
 
+        //====================================================================
+        // Cell API
+        //====================================================================
+
+        [DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
+        internal static extern NewReference PyCell_Get(IntPtr cell);
+
+        [DllImport(_PythonDll, CallingConvention = CallingConvention.Cdecl)]
+        internal static extern int PyCell_Set(IntPtr cell, IntPtr value);
 
         //====================================================================
         // Miscellaneous
diff --git a/src/runtime/typemanager.cs b/src/runtime/typemanager.cs
@@ -280,6 +280,14 @@ internal static IntPtr CreateSubType(IntPtr py_name, IntPtr py_base_type, IntPtr
                 IntPtr cls_dict = Marshal.ReadIntPtr(py_type, TypeOffset.tp_dict);
                 Runtime.PyDict_Update(cls_dict, py_dict);
 
+                // Update the __classcell__ if it exists
+                IntPtr cell = Runtime.PyDict_GetItemString(cls_dict, "__classcell__");
+                if (cell != IntPtr.Zero)
+                {
+                    Runtime.PyCell_Set(cell, py_type);
+                    Runtime.PyDict_DelItemString(cls_dict, "__classcell__");
+                }
+
                 return py_type;
             }
             catch (Exception e)
