libgo: update to Go 1.12.2

    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/170706

From-SVN: r270214

4 files changed, 125 insertions, 16 deletions

diff --git a/libgo/go/net/http/httputil/reverseproxy.go b/libgo/go/net/http/httputil/reverseproxy.go
index 4e10bf3..4b165d6 100644
--- a/libgo/go/net/http/httputil/reverseproxy.go
+++ b/libgo/go/net/http/httputil/reverseproxy.go
@@ -389,6 +389,11 @@ func (p *ReverseProxy) copyResponse(dst io.Writer, src io.Reader, flushInterval
 				latency: flushInterval,
 			}
 			defer mlw.stop()
+
+			// set up initial timer so headers get flushed even if body writes are delayed
+			mlw.flushPending = true
+			mlw.t = time.AfterFunc(flushInterval, mlw.delayedFlush)
+
 			dst = mlw
 		}
 	}
diff --git a/libgo/go/net/http/httputil/reverseproxy_test.go b/libgo/go/net/http/httputil/reverseproxy_test.go
index 5edefa0..367ba73 100644
--- a/libgo/go/net/http/httputil/reverseproxy_test.go
+++ b/libgo/go/net/http/httputil/reverseproxy_test.go
@@ -9,6 +9,7 @@ package httputil
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -317,6 +318,47 @@ func TestReverseProxyFlushInterval(t *testing.T) {
 	}
 }
 
+func TestReverseProxyFlushIntervalHeaders(t *testing.T) {
+	const expected = "hi"
+	stopCh := make(chan struct{})
+	backend := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.Header().Add("MyHeader", expected)
+		w.WriteHeader(200)
+		w.(http.Flusher).Flush()
+		<-stopCh
+	}))
+	defer backend.Close()
+	defer close(stopCh)
+
+	backendURL, err := url.Parse(backend.URL)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	proxyHandler := NewSingleHostReverseProxy(backendURL)
+	proxyHandler.FlushInterval = time.Microsecond
+
+	frontend := httptest.NewServer(proxyHandler)
+	defer frontend.Close()
+
+	req, _ := http.NewRequest("GET", frontend.URL, nil)
+	req.Close = true
+
+	ctx, cancel := context.WithTimeout(req.Context(), 10*time.Second)
+	defer cancel()
+	req = req.WithContext(ctx)
+
+	res, err := frontend.Client().Do(req)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	defer res.Body.Close()
+
+	if res.Header.Get("MyHeader") != expected {
+		t.Errorf("got header %q; expected %q", res.Header.Get("MyHeader"), expected)
+	}
+}
+
 func TestReverseProxyCancelation(t *testing.T) {
 	const backendResponse = "I am the backend"
 
diff --git a/libgo/go/net/lookup.go b/libgo/go/net/lookup.go
index e108893..08e8d01 100644
--- a/libgo/go/net/lookup.go
+++ b/libgo/go/net/lookup.go
@@ -262,8 +262,9 @@ func (r *Resolver) lookupIPAddr(ctx context.Context, network, host string) ([]IP
 	// only the values in context. See Issue 28600.
 	lookupGroupCtx, lookupGroupCancel := context.WithCancel(withUnexpiredValuesPreserved(ctx))
 
+	lookupKey := network + "\000" + host
 	dnsWaitGroup.Add(1)
-	ch, called := r.getLookupGroup().DoChan(host, func() (interface{}, error) {
+	ch, called := r.getLookupGroup().DoChan(lookupKey, func() (interface{}, error) {
 		defer dnsWaitGroup.Done()
 		return testHookLookupIP(lookupGroupCtx, resolverFunc, network, host)
 	})
@@ -280,7 +281,7 @@ func (r *Resolver) lookupIPAddr(ctx context.Context, network, host string) ([]IP
 		// let the lookup continue uncanceled, and let later
 		// lookups with the same key share the result.
 		// See issues 8602, 20703, 22724.
-		if r.getLookupGroup().ForgetUnshared(host) {
+		if r.getLookupGroup().ForgetUnshared(lookupKey) {
 			lookupGroupCancel()
 		} else {
 			go func() {
diff --git a/libgo/go/net/lookup_test.go b/libgo/go/net/lookup_test.go
index 85bcb2b..28a895e 100644
--- a/libgo/go/net/lookup_test.go
+++ b/libgo/go/net/lookup_test.go
@@ -16,6 +16,7 @@ import (
 	"sort"
 	"strings"
 	"sync"
+	"sync/atomic"
 	"testing"
 	"time"
 )
@@ -253,14 +254,11 @@ func TestLookupGmailTXT(t *testing.T) {
 	}
 }
 
-var lookupGooglePublicDNSAddrTests = []struct {
-	addr, name string
-}{
-	{"8.8.8.8", ".google.com."},
-	{"8.8.4.4", ".google.com."},
-
-	{"2001:4860:4860::8888", ".google.com."},
-	{"2001:4860:4860::8844", ".google.com."},
+var lookupGooglePublicDNSAddrTests = []string{
+	"8.8.8.8",
+	"8.8.4.4",
+	"2001:4860:4860::8888",
+	"2001:4860:4860::8844",
 }
 
 func TestLookupGooglePublicDNSAddr(t *testing.T) {
@@ -272,8 +270,8 @@ func TestLookupGooglePublicDNSAddr(t *testing.T) {
 
 	defer dnsWaitGroup.Wait()
 
-	for _, tt := range lookupGooglePublicDNSAddrTests {
-		names, err := LookupAddr(tt.addr)
+	for _, ip := range lookupGooglePublicDNSAddrTests {
+		names, err := LookupAddr(ip)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -281,8 +279,8 @@ func TestLookupGooglePublicDNSAddr(t *testing.T) {
 			t.Error("got no record")
 		}
 		for _, name := range names {
-			if !strings.HasSuffix(name, tt.name) {
-				t.Errorf("got %s; want a record containing %s", name, tt.name)
+			if !strings.HasSuffix(name, ".google.com.") && !strings.HasSuffix(name, ".google.") {
+				t.Errorf("got %q; want a record ending in .google.com. or .google.", name)
 			}
 		}
 	}
@@ -658,8 +656,8 @@ func testDots(t *testing.T, mode string) {
 		t.Errorf("LookupAddr(8.8.8.8): %v (mode=%v)", err, mode)
 	} else {
 		for _, name := range names {
-			if !strings.HasSuffix(name, ".google.com.") {
-				t.Errorf("LookupAddr(8.8.8.8) = %v, want names ending in .google.com. with trailing dot (mode=%v)", names, mode)
+			if !strings.HasSuffix(name, ".google.com.") && !strings.HasSuffix(name, ".google.") {
+				t.Errorf("LookupAddr(8.8.8.8) = %v, want names ending in .google.com or .google with trailing dot (mode=%v)", names, mode)
 				break
 			}
 		}
@@ -1096,6 +1094,69 @@ func TestLookupIPAddrPreservesContextValues(t *testing.T) {
 	}
 }
 
+// Issue 30521: The lookup group should call the resolver for each network.
+func TestLookupIPAddrConcurrentCallsForNetworks(t *testing.T) {
+	origTestHookLookupIP := testHookLookupIP
+	defer func() { testHookLookupIP = origTestHookLookupIP }()
+
+	queries := [][]string{
+		{"udp", "golang.org"},
+		{"udp4", "golang.org"},
+		{"udp6", "golang.org"},
+		{"udp", "golang.org"},
+		{"udp", "golang.org"},
+	}
+	results := map[[2]string][]IPAddr{
+		{"udp", "golang.org"}: {
+			{IP: IPv4(127, 0, 0, 1)},
+			{IP: IPv6loopback},
+		},
+		{"udp4", "golang.org"}: {
+			{IP: IPv4(127, 0, 0, 1)},
+		},
+		{"udp6", "golang.org"}: {
+			{IP: IPv6loopback},
+		},
+	}
+	calls := int32(0)
+	waitCh := make(chan struct{})
+	testHookLookupIP = func(ctx context.Context, fn func(context.Context, string, string) ([]IPAddr, error), network, host string) ([]IPAddr, error) {
+		// We'll block until this is called one time for each different
+		// expected result. This will ensure that the lookup group would wait
+		// for the existing call if it was to be reused.
+		if atomic.AddInt32(&calls, 1) == int32(len(results)) {
+			close(waitCh)
+		}
+		select {
+		case <-waitCh:
+		case <-ctx.Done():
+			return nil, ctx.Err()
+		}
+		return results[[2]string{network, host}], nil
+	}
+
+	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
+	defer cancel()
+	wg := sync.WaitGroup{}
+	for _, q := range queries {
+		network := q[0]
+		host := q[1]
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			gotIPs, err := DefaultResolver.lookupIPAddr(ctx, network, host)
+			if err != nil {
+				t.Errorf("lookupIPAddr(%v, %v): unexpected error: %v", network, host, err)
+			}
+			wantIPs := results[[2]string{network, host}]
+			if !reflect.DeepEqual(gotIPs, wantIPs) {
+				t.Errorf("lookupIPAddr(%v, %v): mismatched IPAddr results\n\tGot: %v\n\tWant: %v", network, host, gotIPs, wantIPs)
+			}
+		}()
+	}
+	wg.Wait()
+}
+
 func TestWithUnexpiredValuesPreserved(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())