Drop tp_call implementation from metatype.

filmor · filmor · commit 350b65a91999 · 2017-06-16T19:54:11.000+02:00
This seems to be a patch for broken behaviour in Python. Removing it should solve #495 (`__init__` called twice on construction).
diff --git a/src/runtime/metatype.cs b/src/runtime/metatype.cs
@@ -1,4 +1,4 @@
-using System;
+﻿using System;
 using System.Runtime.InteropServices;
 
 namespace Python.Runtime
@@ -137,57 +137,6 @@ public static void tp_free(IntPtr tp)
             Runtime.PyObject_GC_Del(tp);
         }
 
-
-        /// <summary>
-        /// Metatype __call__ implementation. This is needed to ensure correct
-        /// initialization (__init__ support), because the tp_call we inherit
-        /// from PyType_Type won't call __init__ for metatypes it doesn't know.
-        /// </summary>
-        public static IntPtr tp_call(IntPtr tp, IntPtr args, IntPtr kw)
-        {
-            IntPtr func = Marshal.ReadIntPtr(tp, TypeOffset.tp_new);
-            if (func == IntPtr.Zero)
-            {
-                return Exceptions.RaiseTypeError("invalid object");
-            }
-
-            IntPtr obj = NativeCall.Call_3(func, tp, args, kw);
-            if (obj == IntPtr.Zero)
-            {
-                return IntPtr.Zero;
-            }
-
-            IntPtr py__init__ = Runtime.PyString_FromString("__init__");
-            IntPtr type = Runtime.PyObject_TYPE(obj);
-            IntPtr init = Runtime._PyType_Lookup(type, py__init__);
-            Runtime.XDecref(py__init__);
-            Runtime.PyErr_Clear();
-
-            if (init != IntPtr.Zero)
-            {
-                IntPtr bound = Runtime.GetBoundArgTuple(obj, args);
-                if (bound == IntPtr.Zero)
-                {
-                    Runtime.XDecref(obj);
-                    return IntPtr.Zero;
-                }
-
-                IntPtr result = Runtime.PyObject_Call(init, bound, kw);
-                Runtime.XDecref(bound);
-
-                if (result == IntPtr.Zero)
-                {
-                    Runtime.XDecref(obj);
-                    return IntPtr.Zero;
-                }
-
-                Runtime.XDecref(result);
-            }
-
-            return obj;
-        }
-
-
         /// <summary>
         /// Type __setattr__ implementation for reflected types. Note that this
         /// is slightly different than the standard setattr implementation for
diff --git a/src/tests/test_subclass.py b/src/tests/test_subclass.py
@@ -190,3 +190,18 @@ def test_isinstance_check():
     for x in b:
         assert isinstance(x, System.Object)
         assert isinstance(x, System.String)
+
+
+def test_derived_constructor_only_called_once():
+    calls = 0
+
+    class X(System.Object):
+        __namespace__ = "PyTest"
+
+        def __init__(self):
+            global calls
+            calls += 1
+
+    x = X()
+
+    assert calls == 1
