Fix error log when loading issues caused by a xorm bug (#7271)

* fix error log when loading issues caused by a xorm bug

* upgrade packages

* fix fmt

* fix Consistency

* fix tests

8 files changed, 102 insertions, 688 deletions

diff --git a/vendor/google.golang.org/appengine/internal/api.go b/vendor/google.golang.org/appengine/internal/api.go
index 16f87c5d37..bbc1cb9c34 100644
--- a/vendor/google.golang.org/appengine/internal/api.go
+++ b/vendor/google.golang.org/appengine/internal/api.go
@@ -3,7 +3,6 @@
 // license that can be found in the LICENSE file.
 
 // +build !appengine
-// +build go1.7
 
 package internal
 
@@ -130,7 +129,13 @@ func handleHTTP(w http.ResponseWriter, r *http.Request) {
 		flushes++
 	}
 	c.pendingLogs.Unlock()
-	go c.flushLog(false)
+	flushed := make(chan struct{})
+	go func() {
+		defer close(flushed)
+		// Force a log flush, because with very short requests we
+		// may not ever flush logs.
+		c.flushLog(true)
+	}()
 	w.Header().Set(logFlushHeader, strconv.Itoa(flushes))
 
 	// Avoid nil Write call if c.Write is never called.
@@ -140,6 +145,9 @@ func handleHTTP(w http.ResponseWriter, r *http.Request) {
 	if c.outBody != nil {
 		w.Write(c.outBody)
 	}
+	// Wait for the last flush to complete before returning,
+	// otherwise the security ticket will not be valid.
+	<-flushed
 }
 
 func executeRequestSafely(c *context, r *http.Request) {
@@ -571,7 +579,10 @@ func logf(c *context, level int64, format string, args ...interface{}) {
 		Level:         &level,
 		Message:       &s,
 	})
-	log.Print(logLevelName[level] + ": " + s)
+	// Only duplicate log to stderr if not running on App Engine second generation
+	if !IsSecondGen() {
+		log.Print(logLevelName[level] + ": " + s)
+	}
 }
 
 // flushLog attempts to flush any pending logs to the appserver.
diff --git a/vendor/google.golang.org/appengine/internal/api_pre17.go b/vendor/google.golang.org/appengine/internal/api_pre17.go
deleted file mode 100644
index 028b4f056e..0000000000
--- a/vendor/google.golang.org/appengine/internal/api_pre17.go
+++ /dev/null
@@ -1,682 +0,0 @@
-// Copyright 2011 Google Inc. All rights reserved.
-// Use of this source code is governed by the Apache 2.0
-// license that can be found in the LICENSE file.
-
-// +build !appengine
-// +build !go1.7
-
-package internal
-
-import (
-	"bytes"
-	"errors"
-	"fmt"
-	"io/ioutil"
-	"log"
-	"net"
-	"net/http"
-	"net/url"
-	"os"
-	"runtime"
-	"strconv"
-	"strings"
-	"sync"
-	"sync/atomic"
-	"time"
-
-	"github.com/golang/protobuf/proto"
-	netcontext "golang.org/x/net/context"
-
-	basepb "google.golang.org/appengine/internal/base"
-	logpb "google.golang.org/appengine/internal/log"
-	remotepb "google.golang.org/appengine/internal/remote_api"
-)
-
-const (
-	apiPath             = "/rpc_http"
-	defaultTicketSuffix = "/default.20150612t184001.0"
-)
-
-var (
-	// Incoming headers.
-	ticketHeader       = http.CanonicalHeaderKey("X-AppEngine-API-Ticket")
-	dapperHeader       = http.CanonicalHeaderKey("X-Google-DapperTraceInfo")
-	traceHeader        = http.CanonicalHeaderKey("X-Cloud-Trace-Context")
-	curNamespaceHeader = http.CanonicalHeaderKey("X-AppEngine-Current-Namespace")
-	userIPHeader       = http.CanonicalHeaderKey("X-AppEngine-User-IP")
-	remoteAddrHeader   = http.CanonicalHeaderKey("X-AppEngine-Remote-Addr")
-
-	// Outgoing headers.
-	apiEndpointHeader      = http.CanonicalHeaderKey("X-Google-RPC-Service-Endpoint")
-	apiEndpointHeaderValue = []string{"app-engine-apis"}
-	apiMethodHeader        = http.CanonicalHeaderKey("X-Google-RPC-Service-Method")
-	apiMethodHeaderValue   = []string{"/VMRemoteAPI.CallRemoteAPI"}
-	apiDeadlineHeader      = http.CanonicalHeaderKey("X-Google-RPC-Service-Deadline")
-	apiContentType         = http.CanonicalHeaderKey("Content-Type")
-	apiContentTypeValue    = []string{"application/octet-stream"}
-	logFlushHeader         = http.CanonicalHeaderKey("X-AppEngine-Log-Flush-Count")
-
-	apiHTTPClient = &http.Client{
-		Transport: &http.Transport{
-			Proxy: http.ProxyFromEnvironment,
-			Dial:  limitDial,
-		},
-	}
-
-	defaultTicketOnce sync.Once
-	defaultTicket     string
-)
-
-func apiURL() *url.URL {
-	host, port := "appengine.googleapis.internal", "10001"
-	if h := os.Getenv("API_HOST"); h != "" {
-		host = h
-	}
-	if p := os.Getenv("API_PORT"); p != "" {
-		port = p
-	}
-	return &url.URL{
-		Scheme: "http",
-		Host:   host + ":" + port,
-		Path:   apiPath,
-	}
-}
-
-func handleHTTP(w http.ResponseWriter, r *http.Request) {
-	c := &context{
-		req:       r,
-		outHeader: w.Header(),
-		apiURL:    apiURL(),
-	}
-	stopFlushing := make(chan int)
-
-	ctxs.Lock()
-	ctxs.m[r] = c
-	ctxs.Unlock()
-	defer func() {
-		ctxs.Lock()
-		delete(ctxs.m, r)
-		ctxs.Unlock()
-	}()
-
-	// Patch up RemoteAddr so it looks reasonable.
-	if addr := r.Header.Get(userIPHeader); addr != "" {
-		r.RemoteAddr = addr
-	} else if addr = r.Header.Get(remoteAddrHeader); addr != "" {
-		r.RemoteAddr = addr
-	} else {
-		// Should not normally reach here, but pick a sensible default anyway.
-		r.RemoteAddr = "127.0.0.1"
-	}
-	// The address in the headers will most likely be of these forms:
-	//	123.123.123.123
-	//	2001:db8::1
-	// net/http.Request.RemoteAddr is specified to be in "IP:port" form.
-	if _, _, err := net.SplitHostPort(r.RemoteAddr); err != nil {
-		// Assume the remote address is only a host; add a default port.
-		r.RemoteAddr = net.JoinHostPort(r.RemoteAddr, "80")
-	}
-
-	// Start goroutine responsible for flushing app logs.
-	// This is done after adding c to ctx.m (and stopped before removing it)
-	// because flushing logs requires making an API call.
-	go c.logFlusher(stopFlushing)
-
-	executeRequestSafely(c, r)
-	c.outHeader = nil // make sure header changes aren't respected any more
-
-	stopFlushing <- 1 // any logging beyond this point will be dropped
-
-	// Flush any pending logs asynchronously.
-	c.pendingLogs.Lock()
-	flushes := c.pendingLogs.flushes
-	if len(c.pendingLogs.lines) > 0 {
-		flushes++
-	}
-	c.pendingLogs.Unlock()
-	go c.flushLog(false)
-	w.Header().Set(logFlushHeader, strconv.Itoa(flushes))
-
-	// Avoid nil Write call if c.Write is never called.
-	if c.outCode != 0 {
-		w.WriteHeader(c.outCode)
-	}
-	if c.outBody != nil {
-		w.Write(c.outBody)
-	}
-}
-
-func executeRequestSafely(c *context, r *http.Request) {
-	defer func() {
-		if x := recover(); x != nil {
-			logf(c, 4, "%s", renderPanic(x)) // 4 == critical
-			c.outCode = 500
-		}
-	}()
-
-	http.DefaultServeMux.ServeHTTP(c, r)
-}
-
-func renderPanic(x interface{}) string {
-	buf := make([]byte, 16<<10) // 16 KB should be plenty
-	buf = buf[:runtime.Stack(buf, false)]
-
-	// Remove the first few stack frames:
-	//   this func
-	//   the recover closure in the caller
-	// That will root the stack trace at the site of the panic.
-	const (
-		skipStart  = "internal.renderPanic"
-		skipFrames = 2
-	)
-	start := bytes.Index(buf, []byte(skipStart))
-	p := start
-	for i := 0; i < skipFrames*2 && p+1 < len(buf); i++ {
-		p = bytes.IndexByte(buf[p+1:], '\n') + p + 1
-		if p < 0 {
-			break
-		}
-	}
-	if p >= 0 {
-		// buf[start:p+1] is the block to remove.
-		// Copy buf[p+1:] over buf[start:] and shrink buf.
-		copy(buf[start:], buf[p+1:])
-		buf = buf[:len(buf)-(p+1-start)]
-	}
-
-	// Add panic heading.
-	head := fmt.Sprintf("panic: %v\n\n", x)
-	if len(head) > len(buf) {
-		// Extremely unlikely to happen.
-		return head
-	}
-	copy(buf[len(head):], buf)
-	copy(buf, head)
-
-	return string(buf)
-}
-
-var ctxs = struct {
-	sync.Mutex
-	m  map[*http.Request]*context
-	bg *context // background context, lazily initialized
-	// dec is used by tests to decorate the netcontext.Context returned
-	// for a given request. This allows tests to add overrides (such as
-	// WithAppIDOverride) to the context. The map is nil outside tests.
-	dec map[*http.Request]func(netcontext.Context) netcontext.Context
-}{
-	m: make(map[*http.Request]*context),
-}
-
-// context represents the context of an in-flight HTTP request.
-// It implements the appengine.Context and http.ResponseWriter interfaces.
-type context struct {
-	req *http.Request
-
-	outCode   int
-	outHeader http.Header
-	outBody   []byte
-
-	pendingLogs struct {
-		sync.Mutex
-		lines   []*logpb.UserAppLogLine
-		flushes int
-	}
-
-	apiURL *url.URL
-}
-
-var contextKey = "holds a *context"
-
-// fromContext returns the App Engine context or nil if ctx is not
-// derived from an App Engine context.
-func fromContext(ctx netcontext.Context) *context {
-	c, _ := ctx.Value(&contextKey).(*context)
-	return c
-}
-
-func withContext(parent netcontext.Context, c *context) netcontext.Context {
-	ctx := netcontext.WithValue(parent, &contextKey, c)
-	if ns := c.req.Header.Get(curNamespaceHeader); ns != "" {
-		ctx = withNamespace(ctx, ns)
-	}
-	return ctx
-}
-
-func toContext(c *context) netcontext.Context {
-	return withContext(netcontext.Background(), c)
-}
-
-func IncomingHeaders(ctx netcontext.Context) http.Header {
-	if c := fromContext(ctx); c != nil {
-		return c.req.Header
-	}
-	return nil
-}
-
-func ReqContext(req *http.Request) netcontext.Context {
-	return WithContext(netcontext.Background(), req)
-}
-
-func WithContext(parent netcontext.Context, req *http.Request) netcontext.Context {
-	ctxs.Lock()
-	c := ctxs.m[req]
-	d := ctxs.dec[req]
-	ctxs.Unlock()
-
-	if d != nil {
-		parent = d(parent)
-	}
-
-	if c == nil {
-		// Someone passed in an http.Request that is not in-flight.
-		// We panic here rather than panicking at a later point
-		// so that stack traces will be more sensible.
-		log.Panic("appengine: NewContext passed an unknown http.Request")
-	}
-	return withContext(parent, c)
-}
-
-// DefaultTicket returns a ticket used for background context or dev_appserver.
-func DefaultTicket() string {
-	defaultTicketOnce.Do(func() {
-		if IsDevAppServer() {
-			defaultTicket = "testapp" + defaultTicketSuffix
-			return
-		}
-		appID := partitionlessAppID()
-		escAppID := strings.Replace(strings.Replace(appID, ":", "_", -1), ".", "_", -1)
-		majVersion := VersionID(nil)
-		if i := strings.Index(majVersion, "."); i > 0 {
-			majVersion = majVersion[:i]
-		}
-		defaultTicket = fmt.Sprintf("%s/%s.%s.%s", escAppID, ModuleName(nil), majVersion, InstanceID())
-	})
-	return defaultTicket
-}
-
-func BackgroundContext() netcontext.Context {
-	ctxs.Lock()
-	defer ctxs.Unlock()
-
-	if ctxs.bg != nil {
-		return toContext(ctxs.bg)
-	}
-
-	// Compute background security ticket.
-	ticket := DefaultTicket()
-
-	ctxs.bg = &context{
-		req: &http.Request{
-			Header: http.Header{
-				ticketHeader: []string{ticket},
-			},
-		},
-		apiURL: apiURL(),
-	}
-
-	// TODO(dsymonds): Wire up the shutdown handler to do a final flush.
-	go ctxs.bg.logFlusher(make(chan int))
-
-	return toContext(ctxs.bg)
-}
-
-// RegisterTestRequest registers the HTTP request req for testing, such that
-// any API calls are sent to the provided URL. It returns a closure to delete
-// the registration.
-// It should only be used by aetest package.
-func RegisterTestRequest(req *http.Request, apiURL *url.URL, decorate func(netcontext.Context) netcontext.Context) (*http.Request, func()) {
-	c := &context{
-		req:    req,
-		apiURL: apiURL,
-	}
-	ctxs.Lock()
-	defer ctxs.Unlock()
-	if _, ok := ctxs.m[req]; ok {
-		log.Panic("req already associated with context")
-	}
-	if _, ok := ctxs.dec[req]; ok {
-		log.Panic("req already associated with context")
-	}
-	if ctxs.dec == nil {
-		ctxs.dec = make(map[*http.Request]func(netcontext.Context) netcontext.Context)
-	}
-	ctxs.m[req] = c
-	ctxs.dec[req] = decorate
-
-	return req, func() {
-		ctxs.Lock()
-		delete(ctxs.m, req)
-		delete(ctxs.dec, req)
-		ctxs.Unlock()
-	}
-}
-
-var errTimeout = &CallError{
-	Detail:  "Deadline exceeded",
-	Code:    int32(remotepb.RpcError_CANCELLED),
-	Timeout: true,
-}
-
-func (c *context) Header() http.Header { return c.outHeader }
-
-// Copied from $GOROOT/src/pkg/net/http/transfer.go. Some response status
-// codes do not permit a response body (nor response entity headers such as
-// Content-Length, Content-Type, etc).
-func bodyAllowedForStatus(status int) bool {
-	switch {
-	case status >= 100 && status <= 199:
-		return false
-	case status == 204:
-		return false
-	case status == 304:
-		return false
-	}
-	return true
-}
-
-func (c *context) Write(b []byte) (int, error) {
-	if c.outCode == 0 {
-		c.WriteHeader(http.StatusOK)
-	}
-	if len(b) > 0 && !bodyAllowedForStatus(c.outCode) {
-		return 0, http.ErrBodyNotAllowed
-	}
-	c.outBody = append(c.outBody, b...)
-	return len(b), nil
-}
-
-func (c *context) WriteHeader(code int) {
-	if c.outCode != 0 {
-		logf(c, 3, "WriteHeader called multiple times on request.") // error level
-		return
-	}
-	c.outCode = code
-}
-
-func (c *context) post(body []byte, timeout time.Duration) (b []byte, err error) {
-	hreq := &http.Request{
-		Method: "POST",
-		URL:    c.apiURL,
-		Header: http.Header{
-			apiEndpointHeader: apiEndpointHeaderValue,
-			apiMethodHeader:   apiMethodHeaderValue,
-			apiContentType:    apiContentTypeValue,
-			apiDeadlineHeader: []string{strconv.FormatFloat(timeout.Seconds(), 'f', -1, 64)},
-		},
-		Body:          ioutil.NopCloser(bytes.NewReader(body)),
-		ContentLength: int64(len(body)),
-		Host:          c.apiURL.Host,
-	}
-	if info := c.req.Header.Get(dapperHeader); info != "" {
-		hreq.Header.Set(dapperHeader, info)
-	}
-	if info := c.req.Header.Get(traceHeader); info != "" {
-		hreq.Header.Set(traceHeader, info)
-	}
-
-	tr := apiHTTPClient.Transport.(*http.Transport)
-
-	var timedOut int32 // atomic; set to 1 if timed out
-	t := time.AfterFunc(timeout, func() {
-		atomic.StoreInt32(&timedOut, 1)
-		tr.CancelRequest(hreq)
-	})
-	defer t.Stop()
-	defer func() {
-		// Check if timeout was exceeded.
-		if atomic.LoadInt32(&timedOut) != 0 {
-			err = errTimeout
-		}
-	}()
-
-	hresp, err := apiHTTPClient.Do(hreq)
-	if err != nil {
-		return nil, &CallError{
-			Detail: fmt.Sprintf("service bridge HTTP failed: %v", err),
-			Code:   int32(remotepb.RpcError_UNKNOWN),
-		}
-	}
-	defer hresp.Body.Close()
-	hrespBody, err := ioutil.ReadAll(hresp.Body)
-	if hresp.StatusCode != 200 {
-		return nil, &CallError{
-			Detail: fmt.Sprintf("service bridge returned HTTP %d (%q)", hresp.StatusCode, hrespBody),
-			Code:   int32(remotepb.RpcError_UNKNOWN),
-		}
-	}
-	if err != nil {
-		return nil, &CallError{
-			Detail: fmt.Sprintf("service bridge response bad: %v", err),
-			Code:   int32(remotepb.RpcError_UNKNOWN),
-		}
-	}
-	return hrespBody, nil
-}
-
-func Call(ctx netcontext.Context, service, method string, in, out proto.Message) error {
-	if ns := NamespaceFromContext(ctx); ns != "" {
-		if fn, ok := NamespaceMods[service]; ok {
-			fn(in, ns)
-		}
-	}
-
-	if f, ctx, ok := callOverrideFromContext(ctx); ok {
-		return f(ctx, service, method, in, out)
-	}
-
-	// Handle already-done contexts quickly.
-	select {
-	case <-ctx.Done():
-		return ctx.Err()
-	default:
-	}
-
-	c := fromContext(ctx)
-	if c == nil {
-		// Give a good error message rather than a panic lower down.
-		return errNotAppEngineContext
-	}
-
-	// Apply transaction modifications if we're in a transaction.
-	if t := transactionFromContext(ctx); t != nil {
-		if t.finished {
-			return errors.New("transaction context has expired")
-		}
-		applyTransaction(in, &t.transaction)
-	}
-
-	// Default RPC timeout is 60s.
-	timeout := 60 * time.Second
-	if deadline, ok := ctx.Deadline(); ok {
-		timeout = deadline.Sub(time.Now())
-	}
-
-	data, err := proto.Marshal(in)
-	if err != nil {
-		return err
-	}
-
-	ticket := c.req.Header.Get(ticketHeader)
-	// Use a test ticket under test environment.
-	if ticket == "" {
-		if appid := ctx.Value(&appIDOverrideKey); appid != nil {
-			ticket = appid.(string) + defaultTicketSuffix
-		}
-	}
-	// Fall back to use background ticket when the request ticket is not available in Flex or dev_appserver.
-	if ticket == "" {
-		ticket = DefaultTicket()
-	}
-	req := &remotepb.Request{
-		ServiceName: &service,
-		Method:      &method,
-		Request:     data,
-		RequestId:   &ticket,
-	}
-	hreqBody, err := proto.Marshal(req)
-	if err != nil {
-		return err
-	}
-
-	hrespBody, err := c.post(hreqBody, timeout)
-	if err != nil {
-		return err
-	}
-
-	res := &remotepb.Response{}
-	if err := proto.Unmarshal(hrespBody, res); err != nil {
-		return err
-	}
-	if res.RpcError != nil {
-		ce := &CallError{
-			Detail: res.RpcError.GetDetail(),
-			Code:   *res.RpcError.Code,
-		}
-		switch remotepb.RpcError_ErrorCode(ce.Code) {
-		case remotepb.RpcError_CANCELLED, remotepb.RpcError_DEADLINE_EXCEEDED:
-			ce.Timeout = true
-		}
-		return ce
-	}
-	if res.ApplicationError != nil {
-		return &APIError{
-			Service: *req.ServiceName,
-			Detail:  res.ApplicationError.GetDetail(),
-			Code:    *res.ApplicationError.Code,
-		}
-	}
-	if res.Exception != nil || res.JavaException != nil {
-		// This shouldn't happen, but let's be defensive.
-		return &CallError{
-			Detail: "service bridge returned exception",
-			Code:   int32(remotepb.RpcError_UNKNOWN),
-		}
-	}
-	return proto.Unmarshal(res.Response, out)
-}
-
-func (c *context) Request() *http.Request {
-	return c.req
-}
-
-func (c *context) addLogLine(ll *logpb.UserAppLogLine) {
-	// Truncate long log lines.
-	// TODO(dsymonds): Check if this is still necessary.
-	const lim = 8 << 10
-	if len(*ll.Message) > lim {
-		suffix := fmt.Sprintf("...(length %d)", len(*ll.Message))
-		ll.Message = proto.String((*ll.Message)[:lim-len(suffix)] + suffix)
-	}
-
-	c.pendingLogs.Lock()
-	c.pendingLogs.lines = append(c.pendingLogs.lines, ll)
-	c.pendingLogs.Unlock()
-}
-
-var logLevelName = map[int64]string{
-	0: "DEBUG",
-	1: "INFO",
-	2: "WARNING",
-	3: "ERROR",
-	4: "CRITICAL",
-}
-
-func logf(c *context, level int64, format string, args ...interface{}) {
-	if c == nil {
-		panic("not an App Engine context")
-	}
-	s := fmt.Sprintf(format, args...)
-	s = strings.TrimRight(s, "\n") // Remove any trailing newline characters.
-	c.addLogLine(&logpb.UserAppLogLine{
-		TimestampUsec: proto.Int64(time.Now().UnixNano() / 1e3),
-		Level:         &level,
-		Message:       &s,
-	})
-	log.Print(logLevelName[level] + ": " + s)
-}
-
-// flushLog attempts to flush any pending logs to the appserver.
-// It should not be called concurrently.
-func (c *context) flushLog(force bool) (flushed bool) {
-	c.pendingLogs.Lock()
-	// Grab up to 30 MB. We can get away with up to 32 MB, but let's be cautious.
-	n, rem := 0, 30<<20
-	for ; n < len(c.pendingLogs.lines); n++ {
-		ll := c.pendingLogs.lines[n]
-		// Each log line will require about 3 bytes of overhead.
-		nb := proto.Size(ll) + 3
-		if nb > rem {
-			break
-		}
-		rem -= nb
-	}
-	lines := c.pendingLogs.lines[:n]
-	c.pendingLogs.lines = c.pendingLogs.lines[n:]
-	c.pendingLogs.Unlock()
-
-	if len(lines) == 0 && !force {
-		// Nothing to flush.
-		return false
-	}
-
-	rescueLogs := false
-	defer func() {
-		if rescueLogs {
-			c.pendingLogs.Lock()
-			c.pendingLogs.lines = append(lines, c.pendingLogs.lines...)
-			c.pendingLogs.Unlock()
-		}
-	}()
-
-	buf, err := proto.Marshal(&logpb.UserAppLogGroup{
-		LogLine: lines,
-	})
-	if err != nil {
-		log.Printf("internal.flushLog: marshaling UserAppLogGroup: %v", err)
-		rescueLogs = true
-		return false
-	}
-
-	req := &logpb.FlushRequest{
-		Logs: buf,
-	}
-	res := &basepb.VoidProto{}
-	c.pendingLogs.Lock()
-	c.pendingLogs.flushes++
-	c.pendingLogs.Unlock()
-	if err := Call(toContext(c), "logservice", "Flush", req, res); err != nil {
-		log.Printf("internal.flushLog: Flush RPC: %v", err)
-		rescueLogs = true
-		return false
-	}
-	return true
-}
-
-const (
-	// Log flushing parameters.
-	flushInterval      = 1 * time.Second
-	forceFlushInterval = 60 * time.Second
-)
-
-func (c *context) logFlusher(stop <-chan int) {
-	lastFlush := time.Now()
-	tick := time.NewTicker(flushInterval)
-	for {
-		select {
-		case <-stop:
-			// Request finished.
-			tick.Stop()
-			return
-		case <-tick.C:
-			force := time.Now().Sub(lastFlush) > forceFlushInterval
-			if c.flushLog(force) {
-				lastFlush = time.Now()
-			}
-		}
-	}
-}
-
-func ContextForTesting(req *http.Request) netcontext.Context {
-	return toContext(&context{req: req})
-}
diff --git a/vendor/google.golang.org/appengine/internal/identity.go b/vendor/google.golang.org/appengine/internal/identity.go
index d538701ab3..9b4134e425 100644
--- a/vendor/google.golang.org/appengine/internal/identity.go
+++ b/vendor/google.golang.org/appengine/internal/identity.go
@@ -4,11 +4,52 @@
 
 package internal
 
-import netcontext "golang.org/x/net/context"
+import (
+	"os"
 
-// These functions are implementations of the wrapper functions
-// in ../appengine/identity.go. See that file for commentary.
+	netcontext "golang.org/x/net/context"
+)
 
+var (
+	// This is set to true in identity_classic.go, which is behind the appengine build tag.
+	// The appengine build tag is set for the first generation runtimes (<= Go 1.9) but not
+	// the second generation runtimes (>= Go 1.11), so this indicates whether we're on a
+	// first-gen runtime. See IsStandard below for the second-gen check.
+	appengineStandard bool
+
+	// This is set to true in identity_flex.go, which is behind the appenginevm build tag.
+	appengineFlex bool
+)
+
+// AppID is the implementation of the wrapper function of the same name in
+// ../identity.go. See that file for commentary.
 func AppID(c netcontext.Context) string {
 	return appID(FullyQualifiedAppID(c))
 }
+
+// IsStandard is the implementation of the wrapper function of the same name in
+// ../appengine.go. See that file for commentary.
+func IsStandard() bool {
+	// appengineStandard will be true for first-gen runtimes (<= Go 1.9) but not
+	// second-gen (>= Go 1.11).
+	return appengineStandard || IsSecondGen()
+}
+
+// IsStandard is the implementation of the wrapper function of the same name in
+// ../appengine.go. See that file for commentary.
+func IsSecondGen() bool {
+	// Second-gen runtimes set $GAE_ENV so we use that to check if we're on a second-gen runtime.
+	return os.Getenv("GAE_ENV") == "standard"
+}
+
+// IsFlex is the implementation of the wrapper function of the same name in
+// ../appengine.go. See that file for commentary.
+func IsFlex() bool {
+	return appengineFlex
+}
+
+// IsAppEngine is the implementation of the wrapper function of the same name in
+// ../appengine.go. See that file for commentary.
+func IsAppEngine() bool {
+	return IsStandard() || IsFlex()
+}
diff --git a/vendor/google.golang.org/appengine/internal/identity_classic.go b/vendor/google.golang.org/appengine/internal/identity_classic.go
index b59603f132..4e979f45e3 100644
--- a/vendor/google.golang.org/appengine/internal/identity_classic.go
+++ b/vendor/google.golang.org/appengine/internal/identity_classic.go
@@ -12,6 +12,10 @@ import (
 	netcontext "golang.org/x/net/context"
 )
 
+func init() {
+	appengineStandard = true
+}
+
 func DefaultVersionHostname(ctx netcontext.Context) string {
 	c := fromContext(ctx)
 	if c == nil {
diff --git a/vendor/google.golang.org/appengine/internal/identity_flex.go b/vendor/google.golang.org/appengine/internal/identity_flex.go
new file mode 100644
index 0000000000..d5e2e7b5e3
--- /dev/null
+++ b/vendor/google.golang.org/appengine/internal/identity_flex.go
@@ -0,0 +1,11 @@
+// Copyright 2018 Google LLC. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+// +build appenginevm
+
+package internal
+
+func init() {
+	appengineFlex = true
+}
diff --git a/vendor/google.golang.org/appengine/internal/main.go b/vendor/google.golang.org/appengine/internal/main.go
index 49036163c2..1e765312fd 100644
--- a/vendor/google.golang.org/appengine/internal/main.go
+++ b/vendor/google.golang.org/appengine/internal/main.go
@@ -11,5 +11,6 @@ import (
 )
 
 func Main() {
+	MainPath = ""
 	appengine_internal.Main()
 }
diff --git a/vendor/google.golang.org/appengine/internal/main_common.go b/vendor/google.golang.org/appengine/internal/main_common.go
new file mode 100644
index 0000000000..357dce4dd0
--- /dev/null
+++ b/vendor/google.golang.org/appengine/internal/main_common.go
@@ -0,0 +1,7 @@
+package internal
+
+// MainPath stores the file path of the main package. On App Engine Standard
+// using Go version 1.9 and below, this will be unset. On App Engine Flex and
+// App Engine Standard second-gen (Go 1.11 and above), this will be the
+// filepath to package main.
+var MainPath string
diff --git a/vendor/google.golang.org/appengine/internal/main_vm.go b/vendor/google.golang.org/appengine/internal/main_vm.go
index 822e784a45..ddb79a3338 100644
--- a/vendor/google.golang.org/appengine/internal/main_vm.go
+++ b/vendor/google.golang.org/appengine/internal/main_vm.go
@@ -12,9 +12,12 @@ import (
 	"net/http"
 	"net/url"
 	"os"
+	"path/filepath"
+	"runtime"
 )
 
 func Main() {
+	MainPath = filepath.Dir(findMainPath())
 	installHealthChecker(http.DefaultServeMux)
 
 	port := "8080"
@@ -31,6 +34,24 @@ func Main() {
 	}
 }
 
+// Find the path to package main by looking at the root Caller.
+func findMainPath() string {
+	pc := make([]uintptr, 100)
+	n := runtime.Callers(2, pc)
+	frames := runtime.CallersFrames(pc[:n])
+	for {
+		frame, more := frames.Next()
+		// Tests won't have package main, instead they have testing.tRunner
+		if frame.Function == "main.main" || frame.Function == "testing.tRunner" {
+			return frame.File
+		}
+		if !more {
+			break
+		}
+	}
+	return ""
+}
+
 func installHealthChecker(mux *http.ServeMux) {
 	// If no health check handler has been installed by this point, add a trivial one.
 	const healthPath = "/_ah/health"