autoleave take two

raft/raft.go

@@ -1445,8 +1445,8 @@ func (r *raft) applyConfChange(cc pb.ConfChangeV2) pb.ConfState {
 		}
 		if cc.LeaveJoint() {
 			return changer.LeaveJoint()
-		} else if autoLeave := cc.EnterJoint(); autoLeave != nil {
-			return changer.EnterJoint(*autoLeave, cc.Changes...)
+		} else if autoLeave, ok := cc.EnterJoint(); ok {
+			return changer.EnterJoint(autoLeave, cc.Changes...)
 		}
 		return changer.Simple(cc.Changes...)
 	}()

raft/raftpb/confchange.go

@@ -66,12 +66,12 @@ func (c ConfChangeV2) AsV2() ConfChangeV2 { return c }
 // AsV1 returns ConfChange{} and false.
 func (c ConfChangeV2) AsV1() (ConfChange, bool) { return ConfChange{}, false }
 
-// EnterJoint returns a pointer to a bool if the configuration change will use
-// Joint Consensus, which is the case if it contains more than one change or the
-// use of Joint Consensus was requested explicitly. The bool is true if the
-// Joint State will be left automatically, and false otherwise.
-// If Joint Consensus will not be used, this method returns nil.
-func (c *ConfChangeV2) EnterJoint() *bool {
+// EnterJoint returns two bools. The second bool is true if and only if this
+// config change will use Joint Consensus, which is the case if it contains more
+// than one change or if the use of Joint Consensus was requested explicitly.
+// The first bool can only be true if second one is, and indicates whether the
+// Joint State will be left automatically.
+func (c *ConfChangeV2) EnterJoint() (autoLeave bool, ok bool) {
 	// NB: in theory, more config changes could qualify for the "simple"
 	// protocol but it depends on the config on top of which the changes apply.
 	// For example, adding two learners is not OK if both nodes are part of the
@@ -90,9 +90,9 @@ func (c *ConfChangeV2) EnterJoint() *bool {
 		default:
 			panic(fmt.Sprintf("unknown transition: %+v", c))
 		}
-		return &autoLeave
+		return autoLeave, true
 	}
-	return nil
+	return false, false
 }
 
 // LeaveJoint is true if the configuration change leaves a joint configuration.