don't rely on hasattr in utils.dir2

Some remote object libraries (e.g. Pyro) will lie to hasattr, not raising AttributeError until the attr is actually requested.
This prevents these AttributeErrors from crashing IPython.

closes gh-543

Signed-off-by: MinRK <[e-mail]>

IPython/utils/dir2.py

@@ -20,8 +20,14 b''
 def get_class_members(cls):
     ret = dir(cls)
     if hasattr(cls,'__bases__'):
-        for base in cls.__bases__:
-            ret.extend(get_class_members(base))
+        try:
+            bases = cls.__bases__
+        except AttributeError:
+            # `obj` lied to hasattr (e.g. Pyro), ignore
+            pass
+        else:
+            for base in bases:
+                ret.extend(get_class_members(base))
     return ret
 
 
@@ -59,6 +65,9 b' def dir2(obj):'
         except TypeError:
             # This will happen if `obj` is a class and not an instance.
             pass
+        except AttributeError:
+            # `obj` lied to hasatter (e.g. Pyro), ignore
+            pass
 
     # Support for PyCrust-style _getAttributeNames magic method.
     if hasattr(obj, '_getAttributeNames'):
@@ -69,6 +78,9 b' def dir2(obj):'
             # `obj` is a class and not an instance.  Ignore
             # this error.
             pass
+        except AttributeError:
+            # `obj` lied to hasatter (e.g. Pyro), ignore
+            pass
 
     if may_have_dupes:
         # eliminate possible duplicates, as some traits may also