fix subinterface handling

3 files changed, 12 insertions, 2 deletions

diff --git a/ChangeLog b/ChangeLog
index 2d008de..3f1bd2f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,7 @@ ChangeLog for logilab.common
 
  --
     * deprecation: new class_moved utility function
+    * interface: fix subinterface handling
 	
 2008-01-10  --  0.26.1
     * optparser: support --version at main command level
diff --git a/interface.py b/interface.py
index 325e470..3589212 100644
--- a/interface.py
+++ b/interface.py
@@ -41,7 +41,7 @@ def implements(obj, interface):
     if not isinstance(kimplements, (list, tuple)):
         kimplements = (kimplements,)
     for implementedinterface in kimplements:
-        if issubclass(interface, implementedinterface):
+        if issubclass(implementedinterface, interface):
             return True
     return False
 
diff --git a/test/unittest_interface.py b/test/unittest_interface.py
index c708ff5..e38e6b1 100644
--- a/test/unittest_interface.py
+++ b/test/unittest_interface.py
@@ -55,7 +55,16 @@ class ExtendTC(TestCase):
         extend(C1, IFace3)
         self.failUnless(C1.__implements__ is c1impl)
         self.failUnless(D.__implements__ is dimpl)
-        
+
+
+    def test_nonregr_implements_baseinterface(self):
+        class SubIFace(IFace1): pass
+        class X(object):
+            __implements__ = (SubIFace,)
+
+        self.failUnless(SubIFace.is_implemented_by(X))
+        self.failUnless(IFace1.is_implemented_by(X))
+
 
 if __name__ == '__main__':
     unittest_main()