[release-branch.go1.10] internal/poll, net: fix sendfile on Windows, add test

Cherry pick of CL 130855, done manually to avoid a merge conflict on the test.

Fixes #27085

Change-Id: I7c4939cf5db23253a824c46c3f00fab4edec86b4
Reviewed-on: https://go-review.googlesource.com/c/146797
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

diff --git a/src/internal/poll/sendfile_windows.go b/src/internal/poll/sendfile_windows.go
index 1a4d0ca1912539f24998869308b1b87c50e2d836..dc93e851d63a459fa599e8307eb48dedf6a188db 100644 (file)
--- a/src/internal/poll/sendfile_windows.go
+++ b/src/internal/poll/sendfile_windows.go
@@ -32,8 +32,8 @@ func SendFile(fd *FD, src syscall.Handle, n int64) (int64, error) {
                return 0, err
        }
 
-       o.o.OffsetHigh = uint32(curpos)
-       o.o.Offset = uint32(curpos >> 32)
+       o.o.Offset = uint32(curpos)
+       o.o.OffsetHigh = uint32(curpos >> 32)
 
        done, err := wsrv.ExecIO(o, func(o *operation) error {
                return syscall.TransmitFile(o.fd.Sysfd, o.handle, o.qty, 0, &o.o, nil, syscall.TF_WRITE_BEHIND)

diff --git a/src/net/sendfile_test.go b/src/net/sendfile_test.go
index 2255e7c47854a67ae3c02a8d8bd0751a42cf0203..76c7f23992a77615c46ba0065b43e1067555e7d2 100644 (file)
--- a/src/net/sendfile_test.go
+++ b/src/net/sendfile_test.go
@@ -5,6 +5,7 @@
 package net
 
 import (
+       "bytes"
        "crypto/sha256"
        "encoding/hex"
        "fmt"
@@ -88,3 +89,64 @@ func TestSendfile(t *testing.T) {
                t.Error(err)
        }
 }
+
+func TestSendfileSeeked(t *testing.T) {
+       ln, err := newLocalListener("tcp")
+       if err != nil {
+               t.Fatal(err)
+       }
+       defer ln.Close()
+
+       const seekTo = 65 << 10
+       const sendSize = 10 << 10
+
+       errc := make(chan error, 1)
+       go func(ln Listener) {
+               // Wait for a connection.
+               conn, err := ln.Accept()
+               if err != nil {
+                       errc <- err
+                       close(errc)
+                       return
+               }
+
+               go func() {
+                       defer close(errc)
+                       defer conn.Close()
+
+                       f, err := os.Open(twain)
+                       if err != nil {
+                               errc <- err
+                               return
+                       }
+                       defer f.Close()
+                       if _, err := f.Seek(seekTo, os.SEEK_SET); err != nil {
+                               errc <- err
+                               return
+                       }
+
+                       _, err = io.CopyN(conn, f, sendSize)
+                       if err != nil {
+                               errc <- err
+                               return
+                       }
+               }()
+       }(ln)
+
+       c, err := Dial("tcp", ln.Addr().String())
+       if err != nil {
+               t.Fatal(err)
+       }
+       defer c.Close()
+
+       buf := new(bytes.Buffer)
+       buf.ReadFrom(c)
+
+       if buf.Len() != sendSize {
+               t.Errorf("Got %d bytes; want %d", buf.Len(), sendSize)
+       }
+
+       for err := range errc {
+               t.Error(err)
+       }
+}