Bump golang.org/x/net

This version includes "x/net/context" which is fully compatible with
the standard Go "context" package, so the two can be mixed together.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

libnetwork/vendor.conf

@@ -48,7 +48,7 @@ github.com/ugorji/go f1f1a805ed361a0e078bb537e4ea78cd37dcf065
 github.com/vishvananda/netlink b2de5d10e38ecce8607e6b438b6d174f389a004e
 github.com/vishvananda/netns 604eaf189ee867d8c147fafc28def2394e878d25
 golang.org/x/crypto 558b6879de74bc843225cde5686419267ff707ca
-golang.org/x/net 7dcfb8076726a3fdd9353b6b8a1f1b6be6811bd6
+golang.org/x/net b3756b4b77d7b13260a0a2ec658753cf48922eac
 golang.org/x/sys 07c182904dbd53199946ba614a412c61d3c548f5
 golang.org/x/sync fd80eb99c8f653c847d294a001bdf2a3a6f768f5
 github.com/pkg/errors 839d9e913e063e28dfd0e6c7b7512793e0a48be9

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

@@ -36,103 +36,6 @@
 // Contexts.
 package context // import "golang.org/x/net/context"
 
-import "time"
-
-// A Context carries a deadline, a cancelation signal, and other values across
-// API boundaries.
-//
-// Context's methods may be called by multiple goroutines simultaneously.
-type Context interface {
-	// Deadline returns the time when work done on behalf of this context
-	// should be canceled. Deadline returns ok==false when no deadline is
-	// set. Successive calls to Deadline return the same results.
-	Deadline() (deadline time.Time, ok bool)
-
-	// Done returns a channel that's closed when work done on behalf of this
-	// context should be canceled. Done may return nil if this context can
-	// never be canceled. Successive calls to Done return the same value.
-	//
-	// WithCancel arranges for Done to be closed when cancel is called;
-	// WithDeadline arranges for Done to be closed when the deadline
-	// expires; WithTimeout arranges for Done to be closed when the timeout
-	// elapses.
-	//
-	// Done is provided for use in select statements:
-	//
-	//  // Stream generates values with DoSomething and sends them to out
-	//  // until DoSomething returns an error or ctx.Done is closed.
-	//  func Stream(ctx context.Context, out chan<- Value) error {
-	//  	for {
-	//  		v, err := DoSomething(ctx)
-	//  		if err != nil {
-	//  			return err
-	//  		}
-	//  		select {
-	//  		case <-ctx.Done():
-	//  			return ctx.Err()
-	//  		case out <- v:
-	//  		}
-	//  	}
-	//  }
-	//
-	// See http://blog.golang.org/pipelines for more examples of how to use
-	// a Done channel for cancelation.
-	Done() <-chan struct{}
-
-	// Err returns a non-nil error value after Done is closed. Err returns
-	// Canceled if the context was canceled or DeadlineExceeded if the
-	// context's deadline passed. No other values for Err are defined.
-	// After Done is closed, successive calls to Err return the same value.
-	Err() error
-
-	// Value returns the value associated with this context for key, or nil
-	// if no value is associated with key. Successive calls to Value with
-	// the same key returns the same result.
-	//
-	// Use context values only for request-scoped data that transits
-	// processes and API boundaries, not for passing optional parameters to
-	// functions.
-	//
-	// A key identifies a specific value in a Context. Functions that wish
-	// to store values in Context typically allocate a key in a global
-	// variable then use that key as the argument to context.WithValue and
-	// Context.Value. A key can be any type that supports equality;
-	// packages should define keys as an unexported type to avoid
-	// collisions.
-	//
-	// Packages that define a Context key should provide type-safe accessors
-	// for the values stores using that key:
-	//
-	// 	// Package user defines a User type that's stored in Contexts.
-	// 	package user
-	//
-	// 	import "golang.org/x/net/context"
-	//
-	// 	// User is the type of value stored in the Contexts.
-	// 	type User struct {...}
-	//
-	// 	// key is an unexported type for keys defined in this package.
-	// 	// This prevents collisions with keys defined in other packages.
-	// 	type key int
-	//
-	// 	// userKey is the key for user.User values in Contexts. It is
-	// 	// unexported; clients use user.NewContext and user.FromContext
-	// 	// instead of using this key directly.
-	// 	var userKey key = 0
-	//
-	// 	// NewContext returns a new Context that carries value u.
-	// 	func NewContext(ctx context.Context, u *User) context.Context {
-	// 		return context.WithValue(ctx, userKey, u)
-	// 	}
-	//
-	// 	// FromContext returns the User value stored in ctx, if any.
-	// 	func FromContext(ctx context.Context) (*User, bool) {
-	// 		u, ok := ctx.Value(userKey).(*User)
-	// 		return u, ok
-	// 	}
-	Value(key interface{}) interface{}
-}
-
 // Background returns a non-nil, empty Context. It is never canceled, has no
 // values, and has no deadline. It is typically used by the main function,
 // initialization, and tests, and as the top-level Context for incoming
@@ -149,8 +52,3 @@ func Background() Context {
 func TODO() Context {
 	return todo
 }
-
-// A CancelFunc tells an operation to abandon its work.
-// A CancelFunc does not wait for the work to stop.
-// After the first call, subsequent calls to a CancelFunc do nothing.
-type CancelFunc func()

libnetwork/vendor/golang.org/x/net/context/go19.go

@@ -0,0 +1,20 @@
+// Copyright 2017 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 go1.9
+
+package context
+
+import "context" // standard library's context, as of Go 1.7
+
+// A Context carries a deadline, a cancelation signal, and other values across
+// API boundaries.
+//
+// Context's methods may be called by multiple goroutines simultaneously.
+type Context = context.Context
+
+// A CancelFunc tells an operation to abandon its work.
+// A CancelFunc does not wait for the work to stop.
+// After the first call, subsequent calls to a CancelFunc do nothing.
+type CancelFunc = context.CancelFunc

libnetwork/vendor/golang.org/x/net/context/pre_go19.go

@@ -0,0 +1,109 @@
+// Copyright 2014 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 !go1.9
+
+package context
+
+import "time"
+
+// A Context carries a deadline, a cancelation signal, and other values across
+// API boundaries.
+//
+// Context's methods may be called by multiple goroutines simultaneously.
+type Context interface {
+	// Deadline returns the time when work done on behalf of this context
+	// should be canceled. Deadline returns ok==false when no deadline is
+	// set. Successive calls to Deadline return the same results.
+	Deadline() (deadline time.Time, ok bool)
+
+	// Done returns a channel that's closed when work done on behalf of this
+	// context should be canceled. Done may return nil if this context can
+	// never be canceled. Successive calls to Done return the same value.
+	//
+	// WithCancel arranges for Done to be closed when cancel is called;
+	// WithDeadline arranges for Done to be closed when the deadline
+	// expires; WithTimeout arranges for Done to be closed when the timeout
+	// elapses.
+	//
+	// Done is provided for use in select statements:
+	//
+	//  // Stream generates values with DoSomething and sends them to out
+	//  // until DoSomething returns an error or ctx.Done is closed.
+	//  func Stream(ctx context.Context, out chan<- Value) error {
+	//  	for {
+	//  		v, err := DoSomething(ctx)
+	//  		if err != nil {
+	//  			return err
+	//  		}
+	//  		select {
+	//  		case <-ctx.Done():
+	//  			return ctx.Err()
+	//  		case out <- v:
+	//  		}
+	//  	}
+	//  }
+	//
+	// See http://blog.golang.org/pipelines for more examples of how to use
+	// a Done channel for cancelation.
+	Done() <-chan struct{}
+
+	// Err returns a non-nil error value after Done is closed. Err returns
+	// Canceled if the context was canceled or DeadlineExceeded if the
+	// context's deadline passed. No other values for Err are defined.
+	// After Done is closed, successive calls to Err return the same value.
+	Err() error
+
+	// Value returns the value associated with this context for key, or nil
+	// if no value is associated with key. Successive calls to Value with
+	// the same key returns the same result.
+	//
+	// Use context values only for request-scoped data that transits
+	// processes and API boundaries, not for passing optional parameters to
+	// functions.
+	//
+	// A key identifies a specific value in a Context. Functions that wish
+	// to store values in Context typically allocate a key in a global
+	// variable then use that key as the argument to context.WithValue and
+	// Context.Value. A key can be any type that supports equality;
+	// packages should define keys as an unexported type to avoid
+	// collisions.
+	//
+	// Packages that define a Context key should provide type-safe accessors
+	// for the values stores using that key:
+	//
+	// 	// Package user defines a User type that's stored in Contexts.
+	// 	package user
+	//
+	// 	import "golang.org/x/net/context"
+	//
+	// 	// User is the type of value stored in the Contexts.
+	// 	type User struct {...}
+	//
+	// 	// key is an unexported type for keys defined in this package.
+	// 	// This prevents collisions with keys defined in other packages.
+	// 	type key int
+	//
+	// 	// userKey is the key for user.User values in Contexts. It is
+	// 	// unexported; clients use user.NewContext and user.FromContext
+	// 	// instead of using this key directly.
+	// 	var userKey key = 0
+	//
+	// 	// NewContext returns a new Context that carries value u.
+	// 	func NewContext(ctx context.Context, u *User) context.Context {
+	// 		return context.WithValue(ctx, userKey, u)
+	// 	}
+	//
+	// 	// FromContext returns the User value stored in ctx, if any.
+	// 	func FromContext(ctx context.Context) (*User, bool) {
+	// 		u, ok := ctx.Value(userKey).(*User)
+	// 		return u, ok
+	// 	}
+	Value(key interface{}) interface{}
+}
+
+// A CancelFunc tells an operation to abandon its work.
+// A CancelFunc does not wait for the work to stop.
+// After the first call, subsequent calls to a CancelFunc do nothing.
+type CancelFunc func()

libnetwork/vendor/golang.org/x/net/proxy/proxy.go

@@ -11,6 +11,7 @@ import (
 	"net"
 	"net/url"
 	"os"
+	"sync"
 )
 
 // A Dialer is a means to establish a connection.
@@ -27,7 +28,7 @@ type Auth struct {
 // FromEnvironment returns the dialer specified by the proxy related variables in
 // the environment.
 func FromEnvironment() Dialer {
-	allProxy := os.Getenv("all_proxy")
+	allProxy := allProxyEnv.Get()
 	if len(allProxy) == 0 {
 		return Direct
 	}
@@ -41,7 +42,7 @@ func FromEnvironment() Dialer {
 		return Direct
 	}
 
-	noProxy := os.Getenv("no_proxy")
+	noProxy := noProxyEnv.Get()
 	if len(noProxy) == 0 {
 		return proxy
 	}
@@ -92,3 +93,42 @@ func FromURL(u *url.URL, forward Dialer) (Dialer, error) {
 
 	return nil, errors.New("proxy: unknown scheme: " + u.Scheme)
 }
+
+var (
+	allProxyEnv = &envOnce{
+		names: []string{"ALL_PROXY", "all_proxy"},
+	}
+	noProxyEnv = &envOnce{
+		names: []string{"NO_PROXY", "no_proxy"},
+	}
+)
+
+// envOnce looks up an environment variable (optionally by multiple
+// names) once. It mitigates expensive lookups on some platforms
+// (e.g. Windows).
+// (Borrowed from net/http/transport.go)
+type envOnce struct {
+	names []string
+	once  sync.Once
+	val   string
+}
+
+func (e *envOnce) Get() string {
+	e.once.Do(e.init)
+	return e.val
+}
+
+func (e *envOnce) init() {
+	for _, n := range e.names {
+		e.val = os.Getenv(n)
+		if e.val != "" {
+			return
+		}
+	}
+}
+
+// reset is used by tests
+func (e *envOnce) reset() {
+	e.once = sync.Once{}
+	e.val = ""
+}