# HG changeset patch
# User Julien Jehannet <julien.jehannet@logilab.fr>
# Date 1295604820 -3600
# Node ID 23554151486c1cd8257178efc1644b291dd9af8f
# Parent  b746dae3a0047c6ea78e75e221893bec43c88d52
[vreg] check for identical app objects when replacing

Prevent from weird behaviour when you badly wrote vreg callback

diff -r b746dae3a004 -r 23554151486c vregistry.py
--- a/vregistry.py	Thu Jan 20 14:38:53 2011 +0100
+++ b/vregistry.py	Fri Jan 21 11:13:40 2011 +0100
@@ -129,6 +129,8 @@
         # or simplify by calling unregister then register here
         if not isinstance(replaced, basestring):
             replaced = classid(replaced)
+        # prevent from misspelling
+        assert obj is not replaced, 'replacing an object by itself: %s' % obj
         registered_objs = self.get(class_regid(obj), ())
         for index, registered in enumerate(registered_objs):
             if classid(registered) == replaced: