fix IndexError when trying to create the first flavor (bug 959232)

this happens when all the default flavors have been deleted and a user tries to add a new one through the WebUI

Change-Id: Ic7779ac2ead409626c1b6ec0540865629e78277e

horizon/dashboards/syspanel/flavors/tests.py

@@ -0,0 +1,26 @@
+from django import http
+from django.core import urlresolvers
+from mox import IsA
+
+from horizon import api
+from horizon.tests.base_tests import BaseHorizonTests
+
+
+class FlavorsTests(BaseHorizonTests):
+    def test_create_new_flavor_when_none_exist(self):
+        # Set admin role
+        self.setActiveUser(token=self.token.id,
+                   username=self.user.name,
+                   tenant_id=self.tenant.id,
+                   service_catalog=self.request.user.service_catalog,
+                   roles=[{'name': 'admin'}])
+
+        self.mox.StubOutWithMock(api, 'flavor_list')
+        # no pre-existing flavors
+        api.flavor_list(IsA(http.HttpRequest)).AndReturn([])
+        self.mox.ReplayAll()
+
+        resp = self.client.get(
+            urlresolvers.reverse('horizon:syspanel:flavors:create'))
+        self.assertEqual(resp.status_code, 200)
+        self.assertTemplateUsed(resp, "syspanel/flavors/create.html")

horizon/dashboards/syspanel/flavors/views.py

@@ -64,5 +64,8 @@ def get_initial(self):
         # TODO(tres): Get rid of this hacky bit of nonsense after flavors get
         # converted to nova client.
         flavors = api.flavor_list(self.request)
-        flavors.sort(key=lambda f: f.id, reverse=True)
-        return {'flavor_id': int(flavors[0].id) + 1}
+        if flavors:
+            largest_id = max(flavors, key=lambda f: f.id).id
+            return {'flavor_id': int(largest_id) + 1}
+        else:
+            return {'flavor_id': 1}