From a33160eb250d9830c63dd3d46a088698150245fc Mon Sep 17 00:00:00 2001
From: David Halter <davidhalter88@gmail.com>
Date: Wed, 29 Aug 2012 23:42:18 +0200
Subject: [PATCH] added parent_stmt to fast_parent_copy, which makes the method
 more reliable

---
 helpers.py | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/helpers.py b/helpers.py
index 0d4b47ef..71e01ebc 100644
--- a/helpers.py
+++ b/helpers.py
@@ -1,6 +1,7 @@
 import copy
 import weakref
 
+from _compatibility import hasattr
 import parsing
 import evaluate
 import debug
@@ -145,10 +146,9 @@ def fast_parent_copy(obj):
     def recursion(obj):
         new_obj = copy.copy(obj)
         new_elements[obj] = new_obj
-        #print new_obj.__dict__
+
         for key, value in new_obj.__dict__.items():
-            #if key in ['_parent_stmt', 'parent_stmt', '_parent', 'parent']: print key, value
-            if key in ['parent', '_parent']:
+            if key in ['parent', '_parent', '_parent_stmt', 'parent_stmt']:
                 continue
             if isinstance(value, list):
                 new_obj.__dict__[key] = list_rec(value)
@@ -161,6 +161,12 @@ def fast_parent_copy(obj):
             except KeyError:
                 pass
 
+        if hasattr(obj, 'parent_stmt') and obj.parent_stmt is not None:
+            try:
+                new_obj.parent_stmt = weakref.ref(new_elements[obj.parent_stmt()])
+            except KeyError:
+                pass
+
         return new_obj
 
     def list_rec(list_obj):