f()
		return
	}
	orig := poll.TestHookDidSendFile
	defer func() {
		poll.TestHookDidSendFile = orig
	}()
	var (
		called     bool
		gotHandled bool
		gotFD      *poll.FD
	)
	poll.TestHookDidSendFile = func(dstFD *poll.FD, src int, written int64, err error, handled bool) {
		if called {
			t.Error("internal/poll.SendFile called multiple times, want one call")
		}
		called = true
		gotHandled = handled

000001a0  90 02 10 55 85 49 48 89  d8 d6 4b 68 29 cb 28 66  |...U.IH...Kh).(f|
000001b0  1c d1 97 e6 a0 10 90 63  83 96 33 ee 5a 5a 5b 66  |.......c..3.ZZ[f|
000001c0  ca b3 0d be 6d 70 c5 de  fd 78 c8 f8 e1 c5 78 ef  |....mp...x....x.|
000001d0  07 2e 60 06 28 86 ed e6  bd 7b 37 33 0e 06 5e 06  |..`.(....{73..^.|
000001e0  fb 44 2b 96 16 fe 09 30  dc 03 53 bc c9 f9 6f 1e  |.D+....0..S...o.|

>>> Flow 2 (server to client)
00000000  16 03 03 00 5d 02 00 00  59 03 03 60 13 bb 4b ce  |....]...Y..`..K.|
00000010  d6 49 3b b2 3a 0c d4 5a  e8 25 26 67 41 fd dd 0f  |.I;.:..Z.%&gA...|
00000020  62 ec c1 ab bc 58 92 67  9d 71 fd 20 20 4c ab 4d  |b....X.g.q.  L.M|
00000030  85 ce 87 49 68 8c cf 9c  2f 7b f9 2b 96 62 8a 75  |...Ih.../{.+.b.u|
00000040  c3 21 05 c6 ab b6 98 5e  e7 e5 d8 4a c0 30 00 00  |.!.....^...J.0..|

		return rv, rc, rn
	}
	return -1, -1, -1
}

func BpxClose(fd int32) (rv int32, rc int32, rn int32) {
	var parms [4]unsafe.Pointer
	parms[0] = unsafe.Pointer(&fd)
	parms[1] = unsafe.Pointer(&rv)
	parms[2] = unsafe.Pointer(&rc)
	parms[3] = unsafe.Pointer(&rn)
	bpxcall(parms[:], BPX4CLO)
	return rv, rc, rn
}

func BpxFileFStat(fd int32, st *Bpxystat_t) (rv int32, rc int32, rn int32) {

			&n, nil, 0)
	})
	return sendRecvMsgFunc.err
}

func WSASendMsg(fd syscall.Handle, msg *WSAMsg, flags uint32, bytesSent *uint32, overlapped *syscall.Overlapped, croutine *byte) error {
	err := loadWSASendRecvMsg()
	if err != nil {
		return err
	}

00000120  7b 1a 4d 12 c8 bf ff 07  39 a9 4e 4e d7 45 35 23  |{.M.....9.NN.E5#|
00000130  9b f9 59 6d a5 b0 49 1b  5f e7 42 62 17 00 1e 57  |..Ym..I._.Bb...W|
00000140  53 c5 22 fb 05 89 fd fe  5d de 71 e8 26 fd 6d e3  |S.".....].q.&.m.|
00000150  fc b9 cb 1f d5 d4 84 d1  67 fe 8a a0 74 ff ad ff  |........g...t...|
00000160  c8 35 fe c2 9a 17 33 18  51 c2 cd 19 7c dc 5d c5  |.5....3.Q...|.].|

00000110  81 00 db 46 7d 93 2e 12  27 06 48 bc 06 28 21 ab  |...F}...'.H..(!.|
00000120  7e c4 b6 a2 5d fe 1e 52  45 88 7a 36 47 a5 08 0d  |~...]..RE.z6G...|
00000130  92 42 5b c2 81 c0 be 97  79 98 40 fb 4f 6d 14 fd  |.B[.....y.@.Om..|
00000140  2b 13 8b c2 a5 2e 67 d8  d4 09 9e d6 22 38 b7 4a  |+.....g....."8.J|
00000150  0b 74 73 2b c2 34 f1 d1  93 e5 96 d9 74 7b f3 58  |.ts+.4......t{.X|

00000110  81 00 db 46 7d 93 2e 12  27 06 48 bc 06 28 21 ab  |...F}...'.H..(!.|
00000120  7e c4 b6 a2 5d fe 1e 52  45 88 7a 36 47 a5 08 0d  |~...]..RE.z6G...|
00000130  92 42 5b c2 81 c0 be 97  79 98 40 fb 4f 6d 14 fd  |.B[.....y.@.Om..|
00000140  2b 13 8b c2 a5 2e 67 d8  d4 09 9e d6 22 38 b7 4a  |+.....g....."8.J|
00000150  0b 74 73 2b c2 34 f1 d1  93 e5 96 d9 74 7b f3 58  |.ts+.4......t{.X|

func loadTzinfoFromZip(zipfile, name string) ([]byte, error) {
	fd, err := open(zipfile)
	if err != nil {
		return nil, err
	}
	defer closefd(fd)

	const (
		zecheader = 0x06054b50
		zcheader  = 0x02014b50
		ztailsize = 22

		zheadersize = 30
		zheader     = 0x04034b50
	)

	buf := make([]byte, ztailsize)
	if err := preadn(fd, buf, -ztailsize); err != nil || get4(buf) != zecheader {

000002c0  cc 0b 24 9d 98 54 d0 dc  90 55 e1 b3 e6 48 69 1a  |..$..T...U...Hi.|
000002d0  55 62 f4 da 8f 60 db f7  76 80 d5 4d 37 f6 43 49  |Ub...`..v..M7.CI|
000002e0  95 3d 96 f6 e2 fd a4 07  ae 24 8c fa bd 02 41 20  |.=.......$....A |
000002f0  a1 50 78 a3 dd 99 c0 cf  74 f1 c0 79 b1 13 9d bc  |.Px.....t..y....|
00000300  0b 37 cf 7c 09 11 b8 a4  71 65 e8 be ff 3a b9 85  |.7.|....qe...:..|