From 840656f9213922d0bb729d201162410b0bd74d9b Mon Sep 17 00:00:00 2001
From: Damien Neil <dneil@google.com>
Date: Tue, 13 Feb 2024 15:36:02 -0800
Subject: [PATCH] quic/qlog: don't output empty slog.Attrs

For golang/go#58547

Change-Id: I49a27ab82781c817511c6f7da0268529abc3f27f
Reviewed-on: https://go-review.googlesource.com/c/net/+/564015
Reviewed-by: Jonathan Amsterdam <jba@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
---
 internal/quic/qlog/json_writer.go      | 6 +++---
 internal/quic/qlog/json_writer_test.go | 9 +++++++++
 2 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/internal/quic/qlog/json_writer.go b/internal/quic/qlog/json_writer.go
index b2fa3e03e..6fb8d33b2 100644
--- a/internal/quic/qlog/json_writer.go
+++ b/internal/quic/qlog/json_writer.go
@@ -45,15 +45,15 @@ func (w *jsonWriter) writeRecordEnd() {
 func (w *jsonWriter) writeAttrs(attrs []slog.Attr) {
 	w.buf.WriteByte('{')
 	for _, a := range attrs {
-		if a.Key == "" {
-			continue
-		}
 		w.writeAttr(a)
 	}
 	w.buf.WriteByte('}')
 }
 
 func (w *jsonWriter) writeAttr(a slog.Attr) {
+	if a.Key == "" {
+		return
+	}
 	w.writeName(a.Key)
 	w.writeValue(a.Value)
 }
diff --git a/internal/quic/qlog/json_writer_test.go b/internal/quic/qlog/json_writer_test.go
index 6da556641..03cf6947c 100644
--- a/internal/quic/qlog/json_writer_test.go
+++ b/internal/quic/qlog/json_writer_test.go
@@ -85,6 +85,15 @@ func TestJSONWriterAttrs(t *testing.T) {
 			`}}`)
 }
 
+func TestJSONWriterAttrEmpty(t *testing.T) {
+	w := newTestJSONWriter()
+	w.writeRecordStart()
+	var a slog.Attr
+	w.writeAttr(a)
+	w.writeRecordEnd()
+	wantJSONRecord(t, w, `{}`)
+}
+
 func TestJSONWriterObjectEmpty(t *testing.T) {
 	w := newTestJSONWriter()
 	w.writeRecordStart()