Update context vendoring

Most fixes here are mostly http2, but since I'm suspecting a bug in
the context package, I thought we better go with the current version
to rule out bugs already fixed.

vendor/golang.org/x/net/context/ctxhttp/ctxhttp.go

@@ -1,7 +1,9 @@
-// Copyright 2015 The Go Authors. All rights reserved.
+// Copyright 2016 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.
 
+// +build go1.7
+
 // Package ctxhttp provides helper functions for performing context-aware HTTP requests.
 package ctxhttp // import "golang.org/x/net/context/ctxhttp"
 
@@ -14,77 +16,28 @@ import (
 	"golang.org/x/net/context"
 )
 
-func nop() {}
-
-var (
-	testHookContextDoneBeforeHeaders = nop
-	testHookDoReturned               = nop
-	testHookDidBodyClose             = nop
-)
-
-// Do sends an HTTP request with the provided http.Client and returns an HTTP response.
+// Do sends an HTTP request with the provided http.Client and returns
+// an HTTP response.
+//
 // If the client is nil, http.DefaultClient is used.
-// If the context is canceled or times out, ctx.Err() will be returned.
+//
+// The provided ctx must be non-nil. If it is canceled or times out,
+// ctx.Err() will be returned.
 func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) {
 	if client == nil {
 		client = http.DefaultClient
 	}
-
-	// TODO(djd): Respect any existing value of req.Cancel.
-	cancel := make(chan struct{})
-	req.Cancel = cancel
-
-	type responseAndError struct {
-		resp *http.Response
-		err  error
-	}
-	result := make(chan responseAndError, 1)
-
-	// Make local copies of test hooks closed over by goroutines below.
-	// Prevents data races in tests.
-	testHookDoReturned := testHookDoReturned
-	testHookDidBodyClose := testHookDidBodyClose
-
-	go func() {
-		resp, err := client.Do(req)
-		testHookDoReturned()
-		result <- responseAndError{resp, err}
-	}()
-
-	var resp *http.Response
-
-	select {
-	case <-ctx.Done():
-		testHookContextDoneBeforeHeaders()
-		close(cancel)
-		// Clean up after the goroutine calling client.Do:
-		go func() {
-			if r := <-result; r.resp != nil {
-				testHookDidBodyClose()
-				r.resp.Body.Close()
-			}
-		}()
-		return nil, ctx.Err()
-	case r := <-result:
-		var err error
-		resp, err = r.resp, r.err
-		if err != nil {
-			return resp, err
-		}
-	}
-
-	c := make(chan struct{})
-	go func() {
+	resp, err := client.Do(req.WithContext(ctx))
+	// If we got an error, and the context has been canceled,
+	// the context's error is probably more useful.
+	if err != nil {
 		select {
 		case <-ctx.Done():
-			close(cancel)
-		case <-c:
-			// The response's Body is closed.
+			err = ctx.Err()
+		default:
 		}
-	}()
-	resp.Body = &notifyingReader{resp.Body, c}
-
-	return resp, nil
+	}
+	return resp, err
 }
 
 // Get issues a GET request via the Do function.
@@ -119,28 +72,3 @@ func Post(ctx context.Context, client *http.Client, url string, bodyType string,
 func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) {
 	return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode()))
 }
-
-// notifyingReader is an io.ReadCloser that closes the notify channel after
-// Close is called or a Read fails on the underlying ReadCloser.
-type notifyingReader struct {
-	io.ReadCloser
-	notify chan<- struct{}
-}
-
-func (r *notifyingReader) Read(p []byte) (int, error) {
-	n, err := r.ReadCloser.Read(p)
-	if err != nil && r.notify != nil {
-		close(r.notify)
-		r.notify = nil
-	}
-	return n, err
-}
-
-func (r *notifyingReader) Close() error {
-	err := r.ReadCloser.Close()
-	if r.notify != nil {
-		close(r.notify)
-		r.notify = nil
-	}
-	return err
-}

vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go

@@ -0,0 +1,147 @@
+// Copyright 2015 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.
+
+// +build !go1.7
+
+package ctxhttp // import "golang.org/x/net/context/ctxhttp"
+
+import (
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"golang.org/x/net/context"
+)
+
+func nop() {}
+
+var (
+	testHookContextDoneBeforeHeaders = nop
+	testHookDoReturned               = nop
+	testHookDidBodyClose             = nop
+)
+
+// Do sends an HTTP request with the provided http.Client and returns an HTTP response.
+// If the client is nil, http.DefaultClient is used.
+// If the context is canceled or times out, ctx.Err() will be returned.
+func Do(ctx context.Context, client *http.Client, req *http.Request) (*http.Response, error) {
+	if client == nil {
+		client = http.DefaultClient
+	}
+
+	// TODO(djd): Respect any existing value of req.Cancel.
+	cancel := make(chan struct{})
+	req.Cancel = cancel
+
+	type responseAndError struct {
+		resp *http.Response
+		err  error
+	}
+	result := make(chan responseAndError, 1)
+
+	// Make local copies of test hooks closed over by goroutines below.
+	// Prevents data races in tests.
+	testHookDoReturned := testHookDoReturned
+	testHookDidBodyClose := testHookDidBodyClose
+
+	go func() {
+		resp, err := client.Do(req)
+		testHookDoReturned()
+		result <- responseAndError{resp, err}
+	}()
+
+	var resp *http.Response
+
+	select {
+	case <-ctx.Done():
+		testHookContextDoneBeforeHeaders()
+		close(cancel)
+		// Clean up after the goroutine calling client.Do:
+		go func() {
+			if r := <-result; r.resp != nil {
+				testHookDidBodyClose()
+				r.resp.Body.Close()
+			}
+		}()
+		return nil, ctx.Err()
+	case r := <-result:
+		var err error
+		resp, err = r.resp, r.err
+		if err != nil {
+			return resp, err
+		}
+	}
+
+	c := make(chan struct{})
+	go func() {
+		select {
+		case <-ctx.Done():
+			close(cancel)
+		case <-c:
+			// The response's Body is closed.
+		}
+	}()
+	resp.Body = &notifyingReader{resp.Body, c}
+
+	return resp, nil
+}
+
+// Get issues a GET request via the Do function.
+func Get(ctx context.Context, client *http.Client, url string) (*http.Response, error) {
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return Do(ctx, client, req)
+}
+
+// Head issues a HEAD request via the Do function.
+func Head(ctx context.Context, client *http.Client, url string) (*http.Response, error) {
+	req, err := http.NewRequest("HEAD", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	return Do(ctx, client, req)
+}
+
+// Post issues a POST request via the Do function.
+func Post(ctx context.Context, client *http.Client, url string, bodyType string, body io.Reader) (*http.Response, error) {
+	req, err := http.NewRequest("POST", url, body)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", bodyType)
+	return Do(ctx, client, req)
+}
+
+// PostForm issues a POST request via the Do function.
+func PostForm(ctx context.Context, client *http.Client, url string, data url.Values) (*http.Response, error) {
+	return Post(ctx, client, url, "application/x-www-form-urlencoded", strings.NewReader(data.Encode()))
+}
+
+// notifyingReader is an io.ReadCloser that closes the notify channel after
+// Close is called or a Read fails on the underlying ReadCloser.
+type notifyingReader struct {
+	io.ReadCloser
+	notify chan<- struct{}
+}
+
+func (r *notifyingReader) Read(p []byte) (int, error) {
+	n, err := r.ReadCloser.Read(p)
+	if err != nil && r.notify != nil {
+		close(r.notify)
+		r.notify = nil
+	}
+	return n, err
+}
+
+func (r *notifyingReader) Close() error {
+	err := r.ReadCloser.Close()
+	if r.notify != nil {
+		close(r.notify)
+		r.notify = nil
+	}
+	return err
+}

vendor/vendor.json

@@ -313,14 +313,14 @@
 		{
 			"checksumSHA1": "9jjO5GjLa0XF/nfWihF02RoH4qc=",
 			"path": "golang.org/x/net/context",
-			"revision": "b400c2eff1badec7022a8c8f5bea058b6315eed7",
-			"revisionTime": "2016-06-19T19:44:24Z"
+			"revision": "b336a971b799939dd16ae9b1df8334cb8b977c4d",
+			"revisionTime": "2016-10-27T19:58:04Z"
 		},
 		{
-			"checksumSHA1": "Do+l129/Bafh54VFaquooqtCcfk=",
+			"checksumSHA1": "WHc3uByvGaMcnSoI21fhzYgbOgg=",
 			"path": "golang.org/x/net/context/ctxhttp",
-			"revision": "b400c2eff1badec7022a8c8f5bea058b6315eed7",
-			"revisionTime": "2016-06-19T19:44:24Z"
+			"revision": "b336a971b799939dd16ae9b1df8334cb8b977c4d",
+			"revisionTime": "2016-10-27T19:58:04Z"
 		},
 		{
 			"checksumSHA1": "/k7k6eJDkxXx6K9Zpo/OwNm58XM=",