only cancel dials when an outbound connection succeeds. this may result in...

only cancel dials when an outbound connection succeeds. this may result in duplicate connections, but it's better to have two connections than dropping both of them and ending up with zero connections.

go.sum

@@ -107,6 +107,7 @@ github.com/libp2p/go-conn-security-multistream v0.1.0/go.mod h1:aw6eD7LOsHEX7+2h
 github.com/libp2p/go-flow-metrics v0.0.1 h1:0gxuFd2GuK7IIP5pKljLwps6TvcuYgvG7Atqi3INF5s=
 github.com/libp2p/go-flow-metrics v0.0.1/go.mod h1:Iv1GH0sG8DtYN3SVJ2eG221wMiNpZxBdp967ls1g+k8=
 github.com/libp2p/go-flow-metrics v0.0.2/go.mod h1:HeoSNUrOJVK1jEpDqVEiUOIXqhbnS27omG0uWU5slZs=
+github.com/libp2p/go-flow-metrics v0.0.3 h1:8tAs/hSdNvUiLgtlSy3mxwxWP4I9y/jlkPFT7epKdeM=
 github.com/libp2p/go-flow-metrics v0.0.3/go.mod h1:HeoSNUrOJVK1jEpDqVEiUOIXqhbnS27omG0uWU5slZs=
 github.com/libp2p/go-libp2p-core v0.0.1 h1:HSTZtFIq/W5Ue43Zw+uWZyy2Vl5WtF0zDjKN8/DT/1I=
 github.com/libp2p/go-libp2p-core v0.0.1/go.mod h1:g/VxnTZ/1ygHxH3dKok7Vno1VfpvGcGip57wjTU4fco=
@@ -291,6 +292,7 @@ github.com/xordataexchange/crypt v0.0.3-0.20170626215501-b2862e3d0a77/go.mod h1:
 go.opencensus.io v0.21.0 h1:mU6zScU4U1YAFPHEHYk+3JC4SY7JxgkqS10ZOSyksNg=
 go.opencensus.io v0.21.0/go.mod h1:mSImk1erAIZhrmZN+AvHh14ztQfjbGwt4TtuofqLduU=
 go.opencensus.io v0.22.1/go.mod h1:Ap50jQcDJrx6rB6VgeeFPtuPIf3wMRvRfrfYDO6+BmA=
+go.opencensus.io v0.22.2 h1:75k/FF0Q2YM8QYo07VPddOLBslDt1MZOdEslOHvmzAs=
 go.opencensus.io v0.22.2/go.mod h1:yxeiOL68Rb0Xd1ddK5vPZ/oVn4vY4Ynel7k9FzqtOIw=
 golang.org/x/crypto v0.0.0-20170930174604-9419663f5a44/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=

swarm.go

@@ -230,7 +230,9 @@ func (s *Swarm) addConn(tc transport.CapableConn, dir network.Direction) (*Conn,
 
 	// We have a connection now. Cancel all other in-progress dials.
 	// This should be fast, no reason to wait till later.
-	s.dsync.CancelDial(p)
+	if dir == network.DirOutbound {
+		s.dsync.CancelDial(p)
+	}
 
 	s.notifyAll(func(f network.Notifiee) {
 		f.Connected(s, c)