PyQt4 QtWebKit failing to load URL, follow redirects to Instagram API endpoints

Question

I am trying to figure out a way to do OOB authorization for instagram for a PyQt4 desktop application. Instagram does not offer a straight-forward way to do so since both implicit and explicit authorization flows require a redirect url Instagram API reference

I am using python-instagram and my idea is the following :

1. Register a dummy URL as my Redirect URI in Instagram ( say : https://www.mydummyuri.com )
2. Get the authorization URL from python-instagram using the *get_authorize_login_url()* method
3. Load this url with QtWebView and connect to the urlChanged SIGNAL
4. Have the user authenticate with his credentials when prompted within the QWebView
5. Catch the URL the user is redirected to after login, will be in the form of https://www.mydummyuri.com?code=xxxxxxxxxxxxx and parse it to extract the code
6. Exchange the code for an access token with API's *exchange_code_for_access_token()*
7. Exit the QtWebView gracefully after saving the token
8. Start making authenticated calls on behalf of the user using this access token.

I have tried the flow using a web-browser and it works fine. However, QtWebView does not seem to handle the redirects correctly. What happens is (numbers correspond to steps above :

1. .

2. I get the authorization url and it is https://instagram.com/accounts/login/?next=/oauth/authorize%3Fredirect_uri%3Dhttps%253A%252F%252Fwww.mydummyuri.com%26response_type%3Dcode%26client_id%3D**MYCLIENTID**
   The urlChanged signal is fired and I get PyQt4.QtCore.QUrl(u'https://instagram.com/accounts/login/?next=/oauth/authorize/?client_id=**MYCLIENTID**&redirect_uri=https://www.mydummyuri.com&response_type=code')

3. URL is loaded and shown into QtWebView
4. User enters username and password , clicks submit
5. The urlChanged signal is fired and I get PyQt4.QtCore.QUrl(u'https://instagram.com/oauth/authorize?redirect_uri=https%3A%2F%2Fwww.mydummyuri.com&response_type=code&client_id=**MYCLIENTID**')
6. QtWebView shows an "Sorry, this page could not be found." page from Instagram. If I try the url from step 5 in my browser ( already authenticated to Instagram ) it will redirect me to https://www.mydummyuri.com?code=xxxxxxxxxxxxx as expected.

Question : What could be the problem with the QtWebView ? Why can't it load the URL and why does it not follow the redirect ?

The test code is simple and minimal but just for the sake of completeness

 api = InstagramAPI(client_id=self.options_string['hidden_client_id'], client_secret=self.options_string['hidden_client_secret'], redirect_uri=self.options_string['redirect_uri'])
 url = api.get_authorize_login_url()
 html = QtWebKit.QWebView()
 html.load(QtCore.QUrl(url))
 html.urlChanged.connect(self.urlChanged)

The urlChanged() just prints the URL it receives from the SIGNAL