reset the RTO timer when queueing an RTO retransmission

ackhandler/sent_packet_handler.go

@@ -329,6 +329,8 @@ func (h *sentPacketHandler) maybeQueuePacketsRTO() {
 		h.congestion.OnRetransmissionTimeout(true)
 		utils.Debugf("\tQueueing packet 0x%x for retransmission (RTO)", packet.PacketNumber)
 		h.queuePacketForRetransmission(el)
+		// Reset the RTO timer here, since it's not clear that this packet contained any retransmittable frames
+		h.lastSentPacketTime = time.Now()
 		return
 	}
 }

ackhandler/sent_packet_handler_test.go

@@ -878,6 +878,7 @@ var _ = Describe("SentPacketHandler", func() {
 				handler.maybeQueuePacketsRTO()
 				Expect(handler.retransmissionQueue).To(HaveLen(1))
 				Expect(handler.retransmissionQueue[0].PacketNumber).To(Equal(p.PacketNumber))
+				Expect(time.Now().Sub(handler.lastSentPacketTime)).To(BeNumerically("<", time.Second/2))
 			})
 		})
 

ackhandlerlegacy/sent_packet_handler.go

@@ -344,6 +344,8 @@ func (h *sentPacketHandler) maybeQueuePacketsRTO() {
 			h.congestion.OnRetransmissionTimeout(true)
 			utils.Debugf("\tQueueing packet 0x%x for retransmission (RTO)", packet.PacketNumber)
 			h.queuePacketForRetransmission(packet)
+			// Reset the RTO timer here, since it's not clear that this packet contained any retransmittable frames
+			h.lastSentPacketTime = time.Now()
 			return
 		}
 	}

ackhandlerlegacy/sent_packet_handler_test.go

@@ -778,6 +778,7 @@ var _ = Describe("SentPacketHandler", func() {
 				handler.maybeQueuePacketsRTO()
 				Expect(handler.retransmissionQueue).To(HaveLen(1))
 				Expect(handler.retransmissionQueue[0]).To(Equal(p))
+				Expect(time.Now().Sub(handler.lastSentPacketTime)).To(BeNumerically("<", time.Second/2))
 			})
 
 			It("does not queue retransmittedpackets", func() {