Issue with functools.partial in 1.10.0 using Python 2.7.9

[joonathan]

When upgrading to 1.10.0 in environment with Python 2.7.0 following exception is thrown:

File "/Users/joonathan/Development/App/application/app.py", line 61, in create_app
configure_extensions(app)
File "/Users/joonathan/Development/App/application/app.py", line 98, in configure_extensions
cors.init_app(app)
File "/Users/joonathan/.virtualenvs/App/lib/python2.7/site-packages/flask_cors.py", line 274, in init_app
app.handle_exception)
File "/Users/joonathan/.virtualenvs/App/lib/python2.7/site-packages/flask_cors.py", line 267, in _after_request_decorator
@wraps(f)
File "/usr/local/Cellar/python/2.7.9/Frameworks/Python.framework/Versions/2.7/lib/python2.7/functools.py", line 33, in update_wrapper
setattr(wrapper, attr, getattr(wrapped, attr))
AttributeError: 'functools.partial' object has no attribute 'module'

[corydolphin]

@joonathan thank you for the bug report, I have found the issue and I a working on a fix.

I am confused that this does not seem to happen in Python != 2.7.9. I don't believe there were any backwards incompatible changes in the 2.7.9 released two days ago.

That said, I have simplified the decorator, so it no longer causes this problem, and is even more readable :-)

PR for reference #85

[corydolphin]

While I was able to repro this by upgrading a virtualenv, I am not able to replicate this in a clean install of 2.7.9. Looking at that stack trace, it looks like something wacky is going on with virtualenv. That stack trace spans multiple Python paths. I was able to cause a similar one:

Traceback (most recent call last):
  File "/Users/Cory/Development/flask-cors/tests/test_exception_interception.py", line 75, in test_acl_abort_500
    resp = self.get('/test_acl_abort_500')
  File "/Users/Cory/Development/flask-cors/tests/base_test.py", line 53, in get
    return self._request('get', *args, **kwargs)
  File "/Users/Cory/Development/flask-cors/tests/base_test.py", line 50, in _request
    return getattr(c, verb)(*args, **kwargs)
  File "/Users/Cory/Development/flask-cors/.env/lib/python2.7/site-packages/werkzeug/test.py", line 762, in get
    return self.open(*args, **kw)
  File "/Users/Cory/Development/flask-cors/.env/lib/python2.7/site-packages/flask/testing.py", line 108, in open
    follow_redirects=follow_redirects)
  File "/Users/Cory/Development/flask-cors/.env/lib/python2.7/site-packages/werkzeug/test.py", line 736, in open
    response = self.run_wsgi_app(environ, buffered=buffered)
  File "/Users/Cory/Development/flask-cors/.env/lib/python2.7/site-packages/werkzeug/test.py", line 659, in run_wsgi_app
    rv = run_wsgi_app(self.application, environ, buffered=buffered)
  File "/Users/Cory/Development/flask-cors/.env/lib/python2.7/site-packages/werkzeug/test.py", line 855, in run_wsgi_app
    app_iter = app(environ, start_response)
  File "/Users/Cory/Development/flask-cors/.env/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "/Users/Cory/Development/flask-cors/.env/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/Users/Cory/Development/flask-cors/flask_cors.py", line 270, in decorator
    return update_wrapper(wrapped_function, f)
  File "/usr/local/Cellar/python/2.7.8_2/Frameworks/Python.framework/Versions/2.7/lib/python2.7/functools.py", line 33, in update_wrapper
    setattr(wrapper, attr, getattr(wrapped, attr))
AttributeError: 'exceptions.AttributeError' object has no attribute '__module__'

I am hopeful that this issue does not occur on a clean install of Python, fingers crossed it is just a OSX issue with virtualenv. I wish my automated testing had caught this! (Looks like Travis CI is still on 2.7.8)

Sorry for the trouble and thanks again for the awesome report!