fix login with a non-unique email where an account linked to another FC account already exists

src/authentic2_auth_fc/views.py

@@ -403,8 +403,11 @@ class LoginOrLinkView(PopupViewMixin, FcOAuthSessionViewMixin, View):
                                             token=self.token)
                     else:
                         self.logger.warning(u'account with email %s already linked to another sub '
-                                            u'%s',
+                                            u'%s, logging anyway',
                                             email, user.fc_accounts.values_list('sub', flat=True))
+                        # login the user anyway, but do not update its user_info, it's not ideal
+                        a2_utils.simulate_login(user, 'france-connect')
+                        return self.redirect(request)
         if user:
             a2_utils.login(request, user, 'france-connect')
             self.fc_account = models.FcAccount.objects.get(sub=self.sub, user=user)