From 3ef77b0c1ad12fbade6ba53a28f15539392cf8ea Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Mon, 14 Sep 2020 10:32:32 +0700
Subject: [PATCH] add an assertion that bytes_in_flight never becomes negative

---
 internal/ackhandler/sent_packet_handler.go | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/internal/ackhandler/sent_packet_handler.go b/internal/ackhandler/sent_packet_handler.go
index d970b61fe..e7b0c293e 100644
--- a/internal/ackhandler/sent_packet_handler.go
+++ b/internal/ackhandler/sent_packet_handler.go
@@ -133,6 +133,9 @@ func (h *sentPacketHandler) DropPackets(encLevel protocol.EncryptionLevel) {
 
 func (h *sentPacketHandler) removeFromBytesInFlight(p *Packet) {
 	if p.includedInBytesInFlight {
+		if p.Length > h.bytesInFlight {
+			panic("negative bytes_in_flight")
+		}
 		h.bytesInFlight -= p.Length
 		p.includedInBytesInFlight = false
 	}