[compat] use instance of the class to have a real instance method (closes: #79268)

Details:

By using `klass` instead of an instance of the class, we bounded the method
as a class method.

During execution, the monkey-patched method considered `self` as a reference
to the class and further use of `self` failed miserably.

3 files changed, 6 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 6bbb6d1..dd7bcf4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,8 @@ ChangeLog for logilab.common
 
  --
     * daemon: change $HOME after dropping privileges (closes #81297)
+    * compat: method_type for py3k use instance of the class to have a
+      real instance method (closes: #79268)
 
 2011-10-12  --  0.57.0
     * only install unittest2 when python version < 2.7 (closes: #76068)
diff --git a/compat.py b/compat.py
index 47ef25c..8983ece 100644
--- a/compat.py
+++ b/compat.py
@@ -63,7 +63,8 @@ except AttributeError:
 # See also http://bugs.python.org/issue11776
 if sys.version_info[0] == 3:
     def method_type(callable, instance, klass):
-        return types.MethodType(callable, klass)
+        # api change. klass is no more considered
+        return types.MethodType(callable, instance)
 else:
     # alias types otherwise
     method_type = types.MethodType
diff --git a/decorators.py b/decorators.py
index 2bce3e8..43c3652 100644
--- a/decorators.py
+++ b/decorators.py
@@ -18,6 +18,7 @@
 """ A few useful function/method decorators. """
 __docformat__ = "restructuredtext en"
 
+import sys
 from time import clock, time
 
 from logilab.common.compat import callable, method_type
@@ -272,7 +273,7 @@ def monkeypatch(klass, methodname=None):
             raise AttributeError('%s has no __name__ attribute: '
                                  'you should provide an explicit `methodname`'
                                  % func)
-        if callable(func):
+        if callable(func) and sys.version_info < (3, 0):
             setattr(klass, name, method_type(func, None, klass))
         else:
             # likely a property