mitsuhiko/flask — pull request #798 by lepture (2013-07-21 05:57:37+00:00)
Title: Fix set cookie every request

Without this patch, the response will always set cookie, even the session is not changed.

For example:

```py
@app.route('/')
def home():
return 'home'

@app.route('/session')
def set_session():
session['foo'] = 'bar'
return 'session'
```

If you have visited `/session`, the next time when you visit '/' it will always send the `Set-Cookie` header.