workaround for bug in functools.update_wrapper for bound methods.

[wickman]

arguably a fix for #223 though there are other places where functools.update_wrapper is called. this is sufficient for my needs.

[wickman]

updated. i'd like to write a regression test but it seems to depend upon a vague external library ('tools') -- any pointers?

[defnull]

Your fix silently ignores class or instance methods. Both are MethodType and not FunctionType.

E.g. someone might want to do this::

controller = MyController()
bottle.route('/', callback=controller.some_method)

This should work as expected and not skip update_wrapper().

I'd prefer a hasattr(module) if that is the only case that triggers the bug.

[wickman]

I agree it should work, but it doesn't:
https://gist.github.com/1238253

instancemethods have neither __module__ nor __name__ and their __doc__ is immutable.

[defnull]

Do you know in which versions of python this bug appears? I tested it with 2.6 and it just worked. I am currently re-building my testing environment.

[defnull]

This code:

class A(object):
  @staticmethod
  def static(): pass

  @classmethod
  def cls(cls): pass

  def method(self): pass

from functools import update_wrapper

def w(): pass

update_wrapper(w, A().method)
update_wrapper(w, A().cls)
update_wrapper(w, A().static)

update_wrapper(w, A.method)
update_wrapper(w, A.cls)
update_wrapper(w, A.static)

works in all 5 supported Python versions: 2.5 2.6 2.7 3.1 3.2

[wickman]

That's because w is not an instancemethod. A simple way to test the functools issue on 2.6.x:

class A(object):
  def A_instance_method(self):
    pass

class B(object):
  @staticmethod
  def static():
    pass

from functools import update_wrapper
update_wrapper(A().A_instance_method, B.static)

It's legitimate to argue that you should never want to wrap instancemethods, but the gist I linked to does this and it actually works just fine if I monkeypatch functools.update_wrapper to something safe for immutable attributes.