From 32a6064defa913ecda62a9510ffc7711bc3c933c Mon Sep 17 00:00:00 2001
From: aidan welch <aidan@freedwave.com>
Date: Fri, 8 Nov 2024 20:18:48 +0100
Subject: [PATCH] net/http/cookiejar: implement concurrent-safe Clear method

Currently clearing all stored cookies puts a needless burden on package consumers, especially when used within http/Client where the calls to the cookiejar are not directly done by the consumer.  This change just directly implements a safe clear of all entries.

Fixes #70258
---
 src/net/http/cookiejar/jar.go      | 10 ++++++++++
 src/net/http/cookiejar/jar_test.go |  8 ++++++++
 2 files changed, 18 insertions(+)

diff --git a/src/net/http/cookiejar/jar.go b/src/net/http/cookiejar/jar.go
index edf14d03ad3..38445d5e12a 100644
--- a/src/net/http/cookiejar/jar.go
+++ b/src/net/http/cookiejar/jar.go
@@ -544,3 +544,13 @@ func (j *Jar) domainAndType(host, domain string) (string, bool, error) {
 
 	return domain, false, nil
 }
+
+// Clear deletes all stored cookies.
+//
+// Clear is safe for concurrent use.
+func (j *Jar) Clear() {
+	j.mu.Lock()
+	defer j.mu.Unlock()
+	clear(j.entries)
+	j.nextSeqNum = 0
+}
diff --git a/src/net/http/cookiejar/jar_test.go b/src/net/http/cookiejar/jar_test.go
index 509560170a5..daabfae916e 100644
--- a/src/net/http/cookiejar/jar_test.go
+++ b/src/net/http/cookiejar/jar_test.go
@@ -670,6 +670,14 @@ func TestBasics(t *testing.T) {
 	}
 }
 
+func TestClear(t *testing.T) {
+	jar := newTestJar()
+	for _, test := range basicsTests {
+		test.run(t, jar)
+		jar.Clear()
+	}
+}
+
 // updateAndDeleteTests contains jarTests which must be performed on the same
 // Jar.
 var updateAndDeleteTests = [...]jarTest{