Display given success message when handle the authorization redirect as unicode string.

[bVTiger]

Hello.

In case if success message text contains unicode characters, for example:
success_message = 'El flujo de autenticación se ha completado. Puede cerrar esta ventana.'
in browser this text is displayed as:
El flujo de autenticación se ha completado. Puede cerrar esta ventana.

I propose make change in line google_auth_oauthlib/flow.py:522:
return [self._success_message.encode("utf-8")]
to
return [self._success_message.encode("raw_unicode_escape")]

[busunkim96]

Hi,

I seem to be able to re-create the incorrect string when I encode with utf-8 and decode with raw_unicode_escape.

>>> success_message = 'El flujo de autenticación se ha completado. Puede cerrar esta ventana.'
>>> print(success_message.encode("utf-8").decode("raw_unicode_escape"))
El flujo de autenticación se ha completado. Puede cerrar esta ventana.

Would adding charset=utf-8 to the response content-type header fix the problem?

google-auth-library-python-oauthlib/google_auth_oauthlib/flow.py

Line 520 in 143a1f8

start_response("200 OK", [("Content-type", "text/plain")])

[bVTiger]

Hi.

Would adding charset=utf-8 to the response content-type header fix the problem?

Yes, add charset=utf-8 to the response content-type header works too.