From 360e3e6b2f9f14429a992a47e9a4df93202f9fee Mon Sep 17 00:00:00 2001
From: Robin Dunn <robin@alldunn.com>
Date: Fri, 27 Jan 2017 20:44:09 -0800
Subject: [PATCH] Instead of using copy.copy to implement Clone, create the new
 instance with __new__

---
 etg/pyevent.py            | 40 ++++++++++-----------------------------
 unittests/test_pyevent.py | 10 ++++++++++
 2 files changed, 20 insertions(+), 30 deletions(-)

diff --git a/etg/pyevent.py b/etg/pyevent.py
index 3e10b818..5cff050d 100644
--- a/etg/pyevent.py
+++ b/etg/pyevent.py
@@ -11,6 +11,8 @@ import etgtools
 import etgtools.tweaker_tools as tools
 from etgtools.extractors import ClassDef, MethodDef, ParamDef
 
+import copy
+
 PACKAGE   = "wx"
 MODULE    = "_core"
 NAME      = "pyevent"   # Base name of the file to generate to for this script
@@ -73,25 +75,14 @@ def run():
             Through the magic of Python this implementation should work for
             this and all derived classes.""",
         body="""\
-            # Create a new instance
-            import copy
-            clone = copy.copy(self)
-            # and then invoke the C++ copy constructor to copy the C++ bits too.
+            # Create a new instance of the same type as this instance and
+            # then invoke the C++ copy constructor to copy the C++ parts and
+            # any custom attributes.
+            clone = wx.PyEvent.__new__(self.__class__)
             wx.PyEvent.__init__(clone, self)
             return clone
             """)
 
-    cls.addPyMethod("__setstate__", "(self, state)",
-        doc = """Sets internal state of PyEvent object. This allows PyEvent to be reconstructed as part of the pickling process""",
-        body = """\
-            self.__dict__.update(state)
-            """)
-
-    cls.addPyMethod("__getstate__", "(self)",
-        doc = "Returns this object's internal state. This is used as part of the pickling process",
-        body = """\
-            return self.__dict__
-            """)
 
     module.addItem(cls)
     cls.addCppCode("IMPLEMENT_DYNAMIC_CLASS(wxPyEvent, wxEvent);")
@@ -142,25 +133,14 @@ def run():
             Through the magic of Python this implementation should work for
             this and all derived classes.""",
         body="""\
-            # Create a new instance
-            import copy
-            clone = copy.copy(self)
-            # and then invoke the C++ copy constructor to copy the C++ bits too.
+            # Create a new instance of the same type as this instance and
+            # then invoke the C++ copy constructor to copy the C++ parts and
+            # any custom attributes.
+            clone = wx.PyCommandEvent.__new__(self.__class__)
             wx.PyCommandEvent.__init__(clone, self)
             return clone
             """)
 
-    cls.addPyMethod("__setstate__", "(self, state)",
-        doc = """Sets internal state of PyEvent object. This allows PyEvent to be reconstructed as part of the pickling process""",
-        body = """\
-            self.__dict__.update(state)
-            """)
-
-    cls.addPyMethod("__getstate__", "(self)",
-        doc = "Returns this object's internal state. This is used as part of the pickling process",
-        body = """\
-            return self.__dict__
-            """)
 
     module.addItem(cls)
     cls.addCppCode("IMPLEMENT_DYNAMIC_CLASS(wxPyCommandEvent, wxCommandEvent);")
diff --git a/unittests/test_pyevent.py b/unittests/test_pyevent.py
index ebd5cbe1..d0b2631b 100644
--- a/unittests/test_pyevent.py
+++ b/unittests/test_pyevent.py
@@ -60,6 +60,16 @@ class PyEvents(unittest.TestCase):
             self.assertTrue(evt1.attr == evt2.attr)
 
 
+    def test_CppCloneDerived(self):
+        # test what happens when Clone is called from C++
+        if hasattr(wx, 'testCppClone'):
+            evt1 = MyPyEvent()
+            evt1.attr = 'testCppClone'
+            evt2 = wx.testCppClone(evt1)
+            self.assertTrue(evt1.attr == evt2.attr)
+            self.assertTrue(isinstance(evt2, MyPyEvent))
+
+
     @unittest.skip('not testing refcounts for now, needs checking...')
     def test_CppCloneRefCounts(self):
         # Since we're doing some funky stuff under the covers with Clone, make