state: avoid panic in watchers

state/relationunit_test.go

Index: state/relationunit_test.go
=== modified file 'state/relationunit_test.go'
--- state/relationunit_test.go	2013-08-30 14:14:09 +0000
+++ state/relationunit_test.go	2013-08-30 15:26:14 +0000
@@ -56,7 +56,7 @@
 }
 
 func (s *RelationUnitSuite) TestPeerSettings(c *gc.C) {
-	pr := NewPeerRelation(c, &s.ConnSuite)
+	pr := NewPeerRelation(c, s.State)
 	rus := RUs{pr.ru0, pr.ru1}
 
 	// Check missing settings cannot be read by any RU.
@@ -275,7 +275,7 @@
 }
 
 func (s *RelationUnitSuite) TestDestroyRelationWithUnitsInScope(c *gc.C) {
-	pr := NewPeerRelation(c, &s.ConnSuite)
+	pr := NewPeerRelation(c, s.State)
 	rel := pr.ru0.Relation()
 
 	// Enter two units, and check that Destroying the service sets the
@@ -347,7 +347,7 @@
 }
 
 func (s *RelationUnitSuite) TestAliveRelationScope(c *gc.C) {
-	pr := NewPeerRelation(c, &s.ConnSuite)
+	pr := NewPeerRelation(c, s.State)
 	rel := pr.ru0.Relation()
 
 	// Two units enter...
@@ -396,8 +396,17 @@
 	s.assertInScope(c, pr.ru3, false)
 }
 
+func (s *StateSuite) TestWatchWatchScopeDiesOnStateClose(c *gc.C) {
+	testWatcherDiesWhenStateCloses(c, func(c *gc.C, st *state.State) waiter {
+		pr := NewPeerRelation(c, st)
+		w := pr.ru0.WatchScope()
+		<-w.Changes()
+		return w
+	})
+}
+
 func (s *RelationUnitSuite) TestPeerWatchScope(c *gc.C) {
-	pr := NewPeerRelation(c, &s.ConnSuite)
+	pr := NewPeerRelation(c, s.State)
 
 	// Test empty initial event.
 	w0 := pr.ru0.WatchScope()
@@ -647,12 +656,12 @@
 	ru0, ru1, ru2, ru3 *state.RelationUnit
 }
 
-func NewPeerRelation(c *gc.C, s *ConnSuite) *PeerRelation {
-	svc, err := s.State.AddService("riak", s.AddTestingCharm(c, "riak"))
+func NewPeerRelation(c *gc.C, st *state.State) *PeerRelation {
+	svc, err := st.AddService("riak", state.AddTestingCharm(c, st, "riak"))
 	c.Assert(err, gc.IsNil)
 	ep, err := svc.Endpoint("ring")
 	c.Assert(err, gc.IsNil)
-	rel, err := s.State.EndpointsRelation(ep)
+	rel, err := st.EndpointsRelation(ep)
 	c.Assert(err, gc.IsNil)
 	pr := &PeerRelation{rel: rel, svc: svc}
 	pr.u0, pr.ru0 = addRU(c, svc, rel, nil)