--- a/vendor/golang.org/x/net/context/ctxhttp/ctxhttp_pre17.go	Wed Sep 18 19:17:42 2019 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,147 +0,0 @@
-// 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
-}