From 75372c214c5a5d1d220e5cc502afffad8d820e21 Mon Sep 17 00:00:00 2001
From: Lars Eggert <lars@eggert.org>
Date: Mon, 16 Sep 2024 04:22:01 -0700
Subject: [PATCH] fix: Don't pace during QNS `zerortt` test (#2115)

If we pace, we might get the initial server flight before sending
sufficient 0-RTT data to pass the QNS check.

Broken out of #1998
---
 neqo-bin/src/client/mod.rs | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/neqo-bin/src/client/mod.rs b/neqo-bin/src/client/mod.rs
index ebbab98286..863b34dced 100644
--- a/neqo-bin/src/client/mod.rs
+++ b/neqo-bin/src/client/mod.rs
@@ -245,15 +245,26 @@ impl Args {
             "handshake" | "transfer" | "retry" | "ecn" => {
                 self.shared.use_old_http = true;
             }
-            "zerortt" | "resumption" => {
+            "resumption" => {
                 if self.urls.len() < 2 {
-                    qerror!("Warning: resumption tests won't work without >1 URL");
+                    qerror!("Warning: resumption test won't work without >1 URL");
+                    exit(127);
+                }
+                self.shared.use_old_http = true;
+                self.resume = true;
+            }
+            "zerortt" => {
+                if self.urls.len() < 2 {
+                    qerror!("Warning: zerortt test won't work without >1 URL");
                     exit(127);
                 }
                 self.shared.use_old_http = true;
                 self.resume = true;
                 // PMTUD probes inflate what we sent in 1-RTT, causing QNS to fail the test.
                 self.shared.quic_parameters.no_pmtud = true;
+                // If we pace, we might get the initial server flight before sending sufficient
+                // 0-RTT data to pass the QNS check. So let's burst.
+                self.shared.quic_parameters.no_pacing = true;
             }
             "multiconnect" => {
                 self.shared.use_old_http = true;