From 23ee196fce0ded06a2f5d0a6f8306d5ca79aead2 Mon Sep 17 00:00:00 2001
From: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue, 29 Jun 2021 11:56:44 +0100
Subject: [PATCH] Don't specify DialContext by default on js/wasm for
 DefaultTransport

---
 AUTHORS                                 |  1 +
 CONTRIBUTORS                            |  1 +
 src/net/http/transport.go               | 18 --------------
 src/net/http/transport_default_js.go    | 26 +++++++++++++++++++++
 src/net/http/transport_default_other.go | 31 +++++++++++++++++++++++++
 5 files changed, 59 insertions(+), 18 deletions(-)
 create mode 100644 src/net/http/transport_default_js.go
 create mode 100644 src/net/http/transport_default_other.go

diff --git a/AUTHORS b/AUTHORS
index 95d3158d20..1edabd3acd 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -1015,6 +1015,7 @@ Nathan Youngman <git@nathany.com>
 Nathaniel Cook <nvcook42@gmail.com>
 Naveen Kumar Sangi <naveenkumarsangi@protonmail.com>
 Neelesh Chandola <neelesh.c98@gmail.com>
+Neil Alexander <neilalexander@neilalexander.dev>
 Neil Lyons <nwjlyons@googlemail.com>
 Netflix, Inc.
 Neuman Vong <neuman.vong@gmail.com>
diff --git a/CONTRIBUTORS b/CONTRIBUTORS
index ee50a4c049..027710eb7b 100644
--- a/CONTRIBUTORS
+++ b/CONTRIBUTORS
@@ -1812,6 +1812,7 @@ Naveen Kumar Sangi <naveenkumarsangi@protonmail.com>
 Neeilan Selvalingam <neeilan96@gmail.com>
 Neelesh Chandola <neelesh.c98@gmail.com>
 Nehal J Wani <nehaljw.kkd1@gmail.com>
+Neil Alexander <neilalexander@neilalexander.dev>
 Neil Lyons <nwjlyons@googlemail.com>
 Neuman Vong <neuman.vong@gmail.com>
 Neven Sajko <nsajko@gmail.com>
diff --git a/src/net/http/transport.go b/src/net/http/transport.go
index 47cb992a50..c0cc8a528f 100644
--- a/src/net/http/transport.go
+++ b/src/net/http/transport.go
@@ -35,24 +35,6 @@ import (
 	"golang.org/x/net/http/httpproxy"
 )
 
-// DefaultTransport is the default implementation of Transport and is
-// used by DefaultClient. It establishes network connections as needed
-// and caches them for reuse by subsequent calls. It uses HTTP proxies
-// as directed by the $HTTP_PROXY and $NO_PROXY (or $http_proxy and
-// $no_proxy) environment variables.
-var DefaultTransport RoundTripper = &Transport{
-	Proxy: ProxyFromEnvironment,
-	DialContext: (&net.Dialer{
-		Timeout:   30 * time.Second,
-		KeepAlive: 30 * time.Second,
-	}).DialContext,
-	ForceAttemptHTTP2:     true,
-	MaxIdleConns:          100,
-	IdleConnTimeout:       90 * time.Second,
-	TLSHandshakeTimeout:   10 * time.Second,
-	ExpectContinueTimeout: 1 * time.Second,
-}
-
 // DefaultMaxIdleConnsPerHost is the default value of Transport's
 // MaxIdleConnsPerHost.
 const DefaultMaxIdleConnsPerHost = 2
diff --git a/src/net/http/transport_default_js.go b/src/net/http/transport_default_js.go
new file mode 100644
index 0000000000..0a2899c0e6
--- /dev/null
+++ b/src/net/http/transport_default_js.go
@@ -0,0 +1,26 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build js && wasm
+// +build js,wasm
+
+package http
+
+import (
+	"time"
+)
+
+// DefaultTransport is the default implementation of Transport and is
+// used by DefaultClient. It uses HTTP proxies as directed by the
+// $HTTP_PROXY and $NO_PROXY (or $http_proxy and $no_proxy) environment
+// variables. No default dialer is specified as the Fetch API will be
+// used in RoundTrip if not specified.
+var DefaultTransport RoundTripper = &Transport{
+	Proxy:                 ProxyFromEnvironment,
+	ForceAttemptHTTP2:     true,
+	MaxIdleConns:          100,
+	IdleConnTimeout:       90 * time.Second,
+	TLSHandshakeTimeout:   10 * time.Second,
+	ExpectContinueTimeout: 1 * time.Second,
+}
diff --git a/src/net/http/transport_default_other.go b/src/net/http/transport_default_other.go
new file mode 100644
index 0000000000..4b6b7b47ea
--- /dev/null
+++ b/src/net/http/transport_default_other.go
@@ -0,0 +1,31 @@
+// Copyright 2021 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build !js || !wasm
+// +build !js !wasm
+
+package http
+
+import (
+	"net"
+	"time"
+)
+
+// DefaultTransport is the default implementation of Transport and is
+// used by DefaultClient. It establishes network connections as needed
+// and caches them for reuse by subsequent calls. It uses HTTP proxies
+// as directed by the $HTTP_PROXY and $NO_PROXY (or $http_proxy and
+// $no_proxy) environment variables.
+var DefaultTransport RoundTripper = &Transport{
+	Proxy: ProxyFromEnvironment,
+	DialContext: (&net.Dialer{
+		Timeout:   30 * time.Second,
+		KeepAlive: 30 * time.Second,
+	}).DialContext,
+	ForceAttemptHTTP2:     true,
+	MaxIdleConns:          100,
+	IdleConnTimeout:       90 * time.Second,
+	TLSHandshakeTimeout:   10 * time.Second,
+	ExpectContinueTimeout: 1 * time.Second,
+}