libgo: Update to weekly.2012-02-22 release.

From-SVN: r184819

12 files changed, 656 insertions, 63 deletions

diff --git a/libgo/go/exp/inotify/inotify_linux_test.go b/libgo/go/exp/inotify/inotify_linux_test.go
index c2160fc..d41d66b 100644
--- a/libgo/go/exp/inotify/inotify_linux_test.go
+++ b/libgo/go/exp/inotify/inotify_linux_test.go
@@ -7,6 +7,7 @@
 package inotify
 
 import (
+	"io/ioutil"
 	"os"
 	"testing"
 	"time"
@@ -16,16 +17,19 @@ func TestInotifyEvents(t *testing.T) {
 	// Create an inotify watcher instance and initialize it
 	watcher, err := NewWatcher()
 	if err != nil {
-		t.Fatalf("NewWatcher() failed: %s", err)
+		t.Fatalf("NewWatcher failed: %s", err)
 	}
 
-	t.Logf("NEEDS TO BE CONVERTED TO NEW GO TOOL") // TODO
-	return
+	dir, err := ioutil.TempDir("", "inotify")
+	if err != nil {
+		t.Fatalf("TempDir failed: %s", err)
+	}
+	defer os.RemoveAll(dir)
 
 	// Add a watch for "_test"
-	err = watcher.Watch("_test")
+	err = watcher.Watch(dir)
 	if err != nil {
-		t.Fatalf("Watcher.Watch() failed: %s", err)
+		t.Fatalf("Watch failed: %s", err)
 	}
 
 	// Receive errors on the error channel on a separate goroutine
@@ -35,7 +39,7 @@ func TestInotifyEvents(t *testing.T) {
 		}
 	}()
 
-	const testFile string = "_test/TestInotifyEvents.testfile"
+	testFile := dir + "/TestInotifyEvents.testfile"
 
 	// Receive events on the event channel on a separate goroutine
 	eventstream := watcher.Event
@@ -58,7 +62,7 @@ func TestInotifyEvents(t *testing.T) {
 	// This should add at least one event to the inotify event queue
 	_, err = os.OpenFile(testFile, os.O_WRONLY|os.O_CREATE, 0666)
 	if err != nil {
-		t.Fatalf("creating test file failed: %s", err)
+		t.Fatalf("creating test file: %s", err)
 	}
 
 	// We expect this event to be received almost immediately, but let's wait 1 s to be sure
@@ -95,7 +99,7 @@ func TestInotifyClose(t *testing.T) {
 		t.Fatal("double Close() test failed: second Close() call didn't return")
 	}
 
-	err := watcher.Watch("_test")
+	err := watcher.Watch(os.TempDir())
 	if err == nil {
 		t.Fatal("expected error on Watch() after Close(), got nil")
 	}
diff --git a/libgo/go/exp/norm/composition.go b/libgo/go/exp/norm/composition.go
index ccff467..2cbe1ac 100644
--- a/libgo/go/exp/norm/composition.go
+++ b/libgo/go/exp/norm/composition.go
@@ -66,6 +66,18 @@ func (rb *reorderBuffer) flush(out []byte) []byte {
 	return out
 }
 
+// flushCopy copies the normalized segment to buf and resets rb.
+// It returns the number of bytes written to buf.
+func (rb *reorderBuffer) flushCopy(buf []byte) int {
+	p := 0
+	for i := 0; i < rb.nrune; i++ {
+		runep := rb.rune[i]
+		p += copy(buf[p:], rb.byte[runep.pos:runep.pos+runep.size])
+	}
+	rb.reset()
+	return p
+}
+
 // insertOrdered inserts a rune in the buffer, ordered by Canonical Combining Class.
 // It returns false if the buffer is not large enough to hold the rune.
 // It is used internally by insert and insertString only.
@@ -96,32 +108,41 @@ func (rb *reorderBuffer) insertOrdered(info runeInfo) bool {
 // insert inserts the given rune in the buffer ordered by CCC.
 // It returns true if the buffer was large enough to hold the decomposed rune.
 func (rb *reorderBuffer) insert(src input, i int, info runeInfo) bool {
-	if info.size == 3 {
-		if rune := src.hangul(i); rune != 0 {
-			return rb.decomposeHangul(rune)
-		}
+	if rune := src.hangul(i); rune != 0 {
+		return rb.decomposeHangul(rune)
 	}
 	if info.hasDecomposition() {
-		dcomp := info.decomposition()
-		rb.tmpBytes = inputBytes(dcomp)
-		for i := 0; i < len(dcomp); {
-			info = rb.f.info(&rb.tmpBytes, i)
-			pos := rb.nbyte
-			if !rb.insertOrdered(info) {
-				return false
-			}
-			end := i + int(info.size)
-			copy(rb.byte[pos:], dcomp[i:end])
-			i = end
-		}
-	} else {
-		// insertOrder changes nbyte
+		return rb.insertDecomposed(info.decomposition())
+	}
+	return rb.insertSingle(src, i, info)
+}
+
+// insertDecomposed inserts an entry in to the reorderBuffer for each rune
+// in dcomp.  dcomp must be a sequence of decomposed UTF-8-encoded runes.
+func (rb *reorderBuffer) insertDecomposed(dcomp []byte) bool {
+	saveNrune, saveNbyte := rb.nrune, rb.nbyte
+	rb.tmpBytes = inputBytes(dcomp)
+	for i := 0; i < len(dcomp); {
+		info := rb.f.info(&rb.tmpBytes, i)
 		pos := rb.nbyte
 		if !rb.insertOrdered(info) {
+			rb.nrune, rb.nbyte = saveNrune, saveNbyte
 			return false
 		}
-		src.copySlice(rb.byte[pos:], i, i+int(info.size))
+		i += copy(rb.byte[pos:], dcomp[i:i+int(info.size)])
+	}
+	return true
+}
+
+// insertSingle inserts an entry in the reorderBuffer for the rune at
+// position i. info is the runeInfo for the rune at position i.
+func (rb *reorderBuffer) insertSingle(src input, i int, info runeInfo) bool {
+	// insertOrder changes nbyte
+	pos := rb.nbyte
+	if !rb.insertOrdered(info) {
+		return false
 	}
+	src.copySlice(rb.byte[pos:], i, i+int(info.size))
 	return true
 }
 
@@ -182,8 +203,12 @@ const (
 	jamoLVTCount = 19 * 21 * 28
 )
 
-// Caller must verify that len(b) >= 3.
+const hangulUTF8Size = 3
+
 func isHangul(b []byte) bool {
+	if len(b) < hangulUTF8Size {
+		return false
+	}
 	b0 := b[0]
 	if b0 < hangulBase0 {
 		return false
@@ -202,8 +227,10 @@ func isHangul(b []byte) bool {
 	return b1 == hangulEnd1 && b[2] < hangulEnd2
 }
 
-// Caller must verify that len(b) >= 3.
 func isHangulString(b string) bool {
+	if len(b) < hangulUTF8Size {
+		return false
+	}
 	b0 := b[0]
 	if b0 < hangulBase0 {
 		return false
@@ -234,6 +261,22 @@ func isHangulWithoutJamoT(b []byte) bool {
 	return c < jamoLVTCount && c%jamoTCount == 0
 }
 
+// decomposeHangul writes the decomposed Hangul to buf and returns the number
+// of bytes written.  len(buf) should be at least 9.
+func decomposeHangul(buf []byte, r rune) int {
+	const JamoUTF8Len = 3
+	r -= hangulBase
+	x := r % jamoTCount
+	r /= jamoTCount
+	utf8.EncodeRune(buf, jamoLBase+r/jamoVCount)
+	utf8.EncodeRune(buf[JamoUTF8Len:], jamoVBase+r%jamoVCount)
+	if x != 0 {
+		utf8.EncodeRune(buf[2*JamoUTF8Len:], jamoTBase+x)
+		return 3 * JamoUTF8Len
+	}
+	return 2 * JamoUTF8Len
+}
+
 // decomposeHangul algorithmically decomposes a Hangul rune into
 // its Jamo components.
 // See http://unicode.org/reports/tr15/#Hangul for details on decomposing Hangul.
diff --git a/libgo/go/exp/norm/composition_test.go b/libgo/go/exp/norm/composition_test.go
index e32380d..9de9eac 100644
--- a/libgo/go/exp/norm/composition_test.go
+++ b/libgo/go/exp/norm/composition_test.go
@@ -47,14 +47,14 @@ func runTests(t *testing.T, name string, fm Form, f insertFunc, tests []TestCase
 	}
 }
 
-func TestFlush(t *testing.T) {
+type flushFunc func(rb *reorderBuffer) []byte
+
+func testFlush(t *testing.T, name string, fn flushFunc) {
 	rb := reorderBuffer{}
 	rb.init(NFC, nil)
-	out := make([]byte, 0)
-
-	out = rb.flush(out)
+	out := fn(&rb)
 	if len(out) != 0 {
-		t.Errorf("wrote bytes on flush of empty buffer. (len(out) = %d)", len(out))
+		t.Errorf("%s: wrote bytes on flush of empty buffer. (len(out) = %d)", name, len(out))
 	}
 
 	for _, r := range []rune("world!") {
@@ -65,16 +65,32 @@ func TestFlush(t *testing.T) {
 	out = rb.flush(out)
 	want := "Hello world!"
 	if string(out) != want {
-		t.Errorf(`output after flush was "%s"; want "%s"`, string(out), want)
+		t.Errorf(`%s: output after flush was "%s"; want "%s"`, name, string(out), want)
 	}
 	if rb.nrune != 0 {
-		t.Errorf("flush: non-null size of info buffer (rb.nrune == %d)", rb.nrune)
+		t.Errorf("%s: non-null size of info buffer (rb.nrune == %d)", name, rb.nrune)
 	}
 	if rb.nbyte != 0 {
-		t.Errorf("flush: non-null size of byte buffer (rb.nbyte == %d)", rb.nbyte)
+		t.Errorf("%s: non-null size of byte buffer (rb.nbyte == %d)", name, rb.nbyte)
 	}
 }
 
+func flushF(rb *reorderBuffer) []byte {
+	out := make([]byte, 0)
+	return rb.flush(out)
+}
+
+func flushCopyF(rb *reorderBuffer) []byte {
+	out := make([]byte, MaxSegmentSize)
+	n := rb.flushCopy(out)
+	return out[:n]
+}
+
+func TestFlush(t *testing.T) {
+	testFlush(t, "flush", flushF)
+	testFlush(t, "flushCopy", flushCopyF)
+}
+
 var insertTests = []TestCase{
 	{[]rune{'a'}, []rune{'a'}},
 	{[]rune{0x300}, []rune{0x300}},
diff --git a/libgo/go/exp/norm/input.go b/libgo/go/exp/norm/input.go
index 5c0968b..9c564d6 100644
--- a/libgo/go/exp/norm/input.go
+++ b/libgo/go/exp/norm/input.go
@@ -7,7 +7,7 @@ package norm
 import "unicode/utf8"
 
 type input interface {
-	skipASCII(p int) int
+	skipASCII(p, max int) int
 	skipNonStarter(p int) int
 	appendSlice(buf []byte, s, e int) []byte
 	copySlice(buf []byte, s, e int)
@@ -18,8 +18,8 @@ type input interface {
 
 type inputString string
 
-func (s inputString) skipASCII(p int) int {
-	for ; p < len(s) && s[p] < utf8.RuneSelf; p++ {
+func (s inputString) skipASCII(p, max int) int {
+	for ; p < max && s[p] < utf8.RuneSelf; p++ {
 	}
 	return p
 }
@@ -59,8 +59,8 @@ func (s inputString) hangul(p int) rune {
 
 type inputBytes []byte
 
-func (s inputBytes) skipASCII(p int) int {
-	for ; p < len(s) && s[p] < utf8.RuneSelf; p++ {
+func (s inputBytes) skipASCII(p, max int) int {
+	for ; p < max && s[p] < utf8.RuneSelf; p++ {
 	}
 	return p
 }
diff --git a/libgo/go/exp/norm/iter.go b/libgo/go/exp/norm/iter.go
new file mode 100644
index 0000000..761ba90
--- /dev/null
+++ b/libgo/go/exp/norm/iter.go
@@ -0,0 +1,286 @@
+// Copyright 2011 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.
+
+package norm
+
+const MaxSegmentSize = maxByteBufferSize
+
+// An Iter iterates over a string or byte slice, while normalizing it
+// to a given Form.
+type Iter struct {
+	rb   reorderBuffer
+	info runeInfo // first character saved from previous iteration
+	next iterFunc // implementation of next depends on form
+
+	p        int // current position in input source
+	outStart int // start of current segment in output buffer
+	inStart  int // start of current segment in input source
+	maxp     int // position in output buffer after which not to start a new segment
+	maxseg   int // for tracking an excess of combining characters
+
+	tccc uint8
+	done bool
+}
+
+type iterFunc func(*Iter, []byte) int
+
+// SetInput initializes i to iterate over src after normalizing it to Form f.
+func (i *Iter) SetInput(f Form, src []byte) {
+	i.rb.init(f, src)
+	if i.rb.f.composing {
+		i.next = nextComposed
+	} else {
+		i.next = nextDecomposed
+	}
+	i.p = 0
+	if i.done = len(src) == 0; !i.done {
+		i.info = i.rb.f.info(i.rb.src, i.p)
+	}
+}
+
+// SetInputString initializes i to iterate over src after normalizing it to Form f.
+func (i *Iter) SetInputString(f Form, src string) {
+	i.rb.initString(f, src)
+	if i.rb.f.composing {
+		i.next = nextComposed
+	} else {
+		i.next = nextDecomposed
+	}
+	i.p = 0
+	if i.done = len(src) == 0; !i.done {
+		i.info = i.rb.f.info(i.rb.src, i.p)
+	}
+}
+
+// Pos returns the byte position at which the next call to Next will commence processing.
+func (i *Iter) Pos() int {
+	return i.p
+}
+
+// Done returns true if there is no more input to process.
+func (i *Iter) Done() bool {
+	return i.done
+}
+
+// Next writes f(i.input[i.Pos():n]...) to buffer buf, where n is the
+// largest boundary of i.input such that the result fits in buf.  
+// It returns the number of bytes written to buf.
+// len(buf) should be at least MaxSegmentSize. 
+// Done must be false before calling Next.
+func (i *Iter) Next(buf []byte) int {
+	return i.next(i, buf)
+}
+
+func (i *Iter) initNext(outn, inStart int) {
+	i.outStart = 0
+	i.inStart = inStart
+	i.maxp = outn - MaxSegmentSize
+	i.maxseg = MaxSegmentSize
+}
+
+// setStart resets the start of the new segment to the given position.
+// It returns true if there is not enough room for the new segment.
+func (i *Iter) setStart(outp, inp int) bool {
+	if outp > i.maxp {
+		return true
+	}
+	i.outStart = outp
+	i.inStart = inp
+	i.maxseg = outp + MaxSegmentSize
+	return false
+}
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
+
+// nextDecomposed is the implementation of Next for forms NFD and NFKD.
+func nextDecomposed(i *Iter, out []byte) int {
+	var outp int
+	i.initNext(len(out), i.p)
+doFast:
+	inCopyStart, outCopyStart := i.p, outp // invariant xCopyStart <= i.xStart
+	for {
+		if sz := int(i.info.size); sz <= 1 {
+			// ASCII or illegal byte.  Either way, advance by 1.
+			i.p++
+			outp++
+			max := min(i.rb.nsrc, len(out)-outp+i.p)
+			if np := i.rb.src.skipASCII(i.p, max); np > i.p {
+				outp += np - i.p
+				i.p = np
+				if i.p >= i.rb.nsrc {
+					break
+				}
+				// ASCII may combine with consecutive runes.
+				if i.setStart(outp-1, i.p-1) {
+					i.p--
+					outp--
+					i.info.size = 1
+					break
+				}
+			}
+		} else if d := i.info.decomposition(); d != nil {
+			i.rb.src.copySlice(out[outCopyStart:], inCopyStart, i.p)
+			p := outp + len(d)
+			if p > i.maxseg && i.setStart(outp, i.p) {
+				return outp
+			}
+			copy(out[outp:], d)
+			outp = p
+			i.p += sz
+			inCopyStart, outCopyStart = i.p, outp
+		} else if r := i.rb.src.hangul(i.p); r != 0 {
+			i.rb.src.copySlice(out[outCopyStart:], inCopyStart, i.p)
+			for {
+				outp += decomposeHangul(out[outp:], r)
+				i.p += hangulUTF8Size
+				if r = i.rb.src.hangul(i.p); r == 0 {
+					break
+				}
+				if i.setStart(outp, i.p) {
+					return outp
+				}
+			}
+			inCopyStart, outCopyStart = i.p, outp
+		} else {
+			p := outp + sz
+			if p > i.maxseg && i.setStart(outp, i.p) {
+				break
+			}
+			outp = p
+			i.p += sz
+		}
+		if i.p >= i.rb.nsrc {
+			break
+		}
+		prevCC := i.info.tccc
+		i.info = i.rb.f.info(i.rb.src, i.p)
+		if cc := i.info.ccc; cc == 0 {
+			if i.setStart(outp, i.p) {
+				break
+			}
+		} else if cc < prevCC {
+			goto doNorm
+		}
+	}
+	if inCopyStart != i.p {
+		i.rb.src.copySlice(out[outCopyStart:], inCopyStart, i.p)
+	}
+	i.done = i.p >= i.rb.nsrc
+	return outp
+doNorm:
+	// Insert what we have decomposed so far in the reorderBuffer.
+	// As we will only reorder, there will always be enough room.
+	i.rb.src.copySlice(out[outCopyStart:], inCopyStart, i.p)
+	if !i.rb.insertDecomposed(out[i.outStart:outp]) {
+		// Start over to prevent decompositions from crossing segment boundaries.
+		// This is a rare occurance.
+		i.p = i.inStart
+		i.info = i.rb.f.info(i.rb.src, i.p)
+	}
+	outp = i.outStart
+	for {
+		if !i.rb.insert(i.rb.src, i.p, i.info) {
+			break
+		}
+		if i.p += int(i.info.size); i.p >= i.rb.nsrc {
+			outp += i.rb.flushCopy(out[outp:])
+			i.done = true
+			return outp
+		}
+		i.info = i.rb.f.info(i.rb.src, i.p)
+		if i.info.ccc == 0 {
+			break
+		}
+	}
+	// new segment or too many combining characters: exit normalization
+	if outp += i.rb.flushCopy(out[outp:]); i.setStart(outp, i.p) {
+		return outp
+	}
+	goto doFast
+}
+
+// nextComposed is the implementation of Next for forms NFC and NFKC.
+func nextComposed(i *Iter, out []byte) int {
+	var outp int
+	i.initNext(len(out), i.p)
+doFast:
+	inCopyStart, outCopyStart := i.p, outp // invariant xCopyStart <= i.xStart
+	var prevCC uint8
+	for {
+		if !i.info.isYesC() {
+			goto doNorm
+		}
+		if cc := i.info.ccc; cc == 0 {
+			if i.setStart(outp, i.p) {
+				break
+			}
+		} else if cc < prevCC {
+			goto doNorm
+		}
+		prevCC = i.info.tccc
+		sz := int(i.info.size)
+		if sz == 0 {
+			sz = 1 // illegal rune: copy byte-by-byte
+		}
+		p := outp + sz
+		if p > i.maxseg && i.setStart(outp, i.p) {
+			break
+		}
+		outp = p
+		i.p += sz
+		max := min(i.rb.nsrc, len(out)-outp+i.p)
+		if np := i.rb.src.skipASCII(i.p, max); np > i.p {
+			outp += np - i.p
+			i.p = np
+			if i.p >= i.rb.nsrc {
+				break
+			}
+			// ASCII may combine with consecutive runes.
+			if i.setStart(outp-1, i.p-1) {
+				i.p--
+				outp--
+				i.info = runeInfo{size: 1}
+				break
+			}
+		}
+		if i.p >= i.rb.nsrc {
+			break
+		}
+		i.info = i.rb.f.info(i.rb.src, i.p)
+	}
+	if inCopyStart != i.p {
+		i.rb.src.copySlice(out[outCopyStart:], inCopyStart, i.p)
+	}
+	i.done = i.p >= i.rb.nsrc
+	return outp
+doNorm:
+	i.rb.src.copySlice(out[outCopyStart:], inCopyStart, i.inStart)
+	outp, i.p = i.outStart, i.inStart
+	i.info = i.rb.f.info(i.rb.src, i.p)
+	for {
+		if !i.rb.insert(i.rb.src, i.p, i.info) {
+			break
+		}
+		if i.p += int(i.info.size); i.p >= i.rb.nsrc {
+			i.rb.compose()
+			outp += i.rb.flushCopy(out[outp:])
+			i.done = true
+			return outp
+		}
+		i.info = i.rb.f.info(i.rb.src, i.p)
+		if i.info.boundaryBefore() {
+			break
+		}
+	}
+	i.rb.compose()
+	if outp += i.rb.flushCopy(out[outp:]); i.setStart(outp, i.p) {
+		return outp
+	}
+	goto doFast
+}
diff --git a/libgo/go/exp/norm/iter_test.go b/libgo/go/exp/norm/iter_test.go
new file mode 100644
index 0000000..f6e8d81
--- /dev/null
+++ b/libgo/go/exp/norm/iter_test.go
@@ -0,0 +1,186 @@
+// Copyright 2011 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.
+
+package norm
+
+import (
+	"strings"
+	"testing"
+)
+
+var iterBufSizes = []int{
+	MaxSegmentSize,
+	1.5 * MaxSegmentSize,
+	2 * MaxSegmentSize,
+	3 * MaxSegmentSize,
+	100 * MaxSegmentSize,
+}
+
+func doIterNorm(f Form, buf []byte, s string) []byte {
+	acc := []byte{}
+	i := Iter{}
+	i.SetInputString(f, s)
+	for !i.Done() {
+		n := i.Next(buf)
+		acc = append(acc, buf[:n]...)
+	}
+	return acc
+}
+
+func runIterTests(t *testing.T, name string, f Form, tests []AppendTest, norm bool) {
+	for i, test := range tests {
+		in := test.left + test.right
+		gold := test.out
+		if norm {
+			gold = string(f.AppendString(nil, test.out))
+		}
+		for _, sz := range iterBufSizes {
+			buf := make([]byte, sz)
+			out := string(doIterNorm(f, buf, in))
+			if len(out) != len(gold) {
+				const msg = "%s:%d:%d: length is %d; want %d"
+				t.Errorf(msg, name, i, sz, len(out), len(gold))
+			}
+			if out != gold {
+				// Find first rune that differs and show context.
+				ir := []rune(out)
+				ig := []rune(gold)
+				for j := 0; j < len(ir) && j < len(ig); j++ {
+					if ir[j] == ig[j] {
+						continue
+					}
+					if j -= 3; j < 0 {
+						j = 0
+					}
+					for e := j + 7; j < e && j < len(ir) && j < len(ig); j++ {
+						const msg = "%s:%d:%d: runeAt(%d) = %U; want %U"
+						t.Errorf(msg, name, i, sz, j, ir[j], ig[j])
+					}
+					break
+				}
+			}
+		}
+	}
+}
+
+func rep(r rune, n int) string {
+	return strings.Repeat(string(r), n)
+}
+
+var iterTests = []AppendTest{
+	{"", ascii, ascii},
+	{"", txt_all, txt_all},
+	{"", "a" + rep(0x0300, MaxSegmentSize/2), "a" + rep(0x0300, MaxSegmentSize/2)},
+}
+
+var iterTestsD = []AppendTest{
+	{ // segment overflow on unchanged character
+		"",
+		"a" + rep(0x0300, MaxSegmentSize/2) + "\u0316",
+		"a" + rep(0x0300, MaxSegmentSize/2-1) + "\u0316\u0300",
+	},
+	{ // segment overflow on unchanged character + start value
+		"",
+		"a" + rep(0x0300, MaxSegmentSize/2+maxCombiningChars+4) + "\u0316",
+		"a" + rep(0x0300, MaxSegmentSize/2+maxCombiningChars) + "\u0316" + rep(0x300, 4),
+	},
+	{ // segment overflow on decomposition
+		"",
+		"a" + rep(0x0300, MaxSegmentSize/2-1) + "\u0340",
+		"a" + rep(0x0300, MaxSegmentSize/2),
+	},
+	{ // segment overflow on decomposition + start value
+		"",
+		"a" + rep(0x0300, MaxSegmentSize/2-1) + "\u0340" + rep(0x300, maxCombiningChars+4) + "\u0320",
+		"a" + rep(0x0300, MaxSegmentSize/2-1) + rep(0x300, maxCombiningChars+1) + "\u0320" + rep(0x300, 4),
+	},
+	{ // start value after ASCII overflow
+		"",
+		rep('a', MaxSegmentSize) + rep(0x300, maxCombiningChars+2) + "\u0320",
+		rep('a', MaxSegmentSize) + rep(0x300, maxCombiningChars) + "\u0320\u0300\u0300",
+	},
+	{ // start value after Hangul overflow
+		"",
+		rep(0xAC00, MaxSegmentSize/6) + rep(0x300, maxCombiningChars+2) + "\u0320",
+		strings.Repeat("\u1100\u1161", MaxSegmentSize/6) + rep(0x300, maxCombiningChars-1) + "\u0320" + rep(0x300, 3),
+	},
+	{ // start value after cc=0
+		"",
+		"您您" + rep(0x300, maxCombiningChars+4) + "\u0320",
+		"您您" + rep(0x300, maxCombiningChars) + "\u0320" + rep(0x300, 4),
+	},
+	{ // start value after normalization
+		"",
+		"\u0300\u0320a" + rep(0x300, maxCombiningChars+4) + "\u0320",
+		"\u0320\u0300a" + rep(0x300, maxCombiningChars) + "\u0320" + rep(0x300, 4),
+	},
+}
+
+var iterTestsC = []AppendTest{
+	{ // ordering of non-composing combining characters
+		"",
+		"\u0305\u0316",
+		"\u0316\u0305",
+	},
+	{ // segment overflow
+		"",
+		"a" + rep(0x0305, MaxSegmentSize/2+4) + "\u0316",
+		"a" + rep(0x0305, MaxSegmentSize/2-1) + "\u0316" + rep(0x305, 5),
+	},
+}
+
+func TestIterNextD(t *testing.T) {
+	runIterTests(t, "IterNextD1", NFKD, appendTests, true)
+	runIterTests(t, "IterNextD2", NFKD, iterTests, true)
+	runIterTests(t, "IterNextD3", NFKD, iterTestsD, false)
+}
+
+func TestIterNextC(t *testing.T) {
+	runIterTests(t, "IterNextC1", NFKC, appendTests, true)
+	runIterTests(t, "IterNextC2", NFKC, iterTests, true)
+	runIterTests(t, "IterNextC3", NFKC, iterTestsC, false)
+}
+
+type SegmentTest struct {
+	in  string
+	out []string
+}
+
+var segmentTests = []SegmentTest{
+	{rep('a', MaxSegmentSize), []string{rep('a', MaxSegmentSize), ""}},
+	{rep('a', MaxSegmentSize+2), []string{rep('a', MaxSegmentSize-1), "aaa", ""}},
+	{rep('a', MaxSegmentSize) + "\u0300aa", []string{rep('a', MaxSegmentSize-1), "a\u0300", "aa", ""}},
+}
+
+// Note that, by design, segmentation is equal for composing and decomposing forms.
+func TestIterSegmentation(t *testing.T) {
+	segmentTest(t, "SegmentTestD", NFD, segmentTests)
+	segmentTest(t, "SegmentTestC", NFC, segmentTests)
+}
+
+func segmentTest(t *testing.T, name string, f Form, tests []SegmentTest) {
+	iter := Iter{}
+	for i, tt := range segmentTests {
+		buf := make([]byte, MaxSegmentSize)
+		iter.SetInputString(f, tt.in)
+		for j, seg := range tt.out {
+			if seg == "" {
+				if !iter.Done() {
+					n := iter.Next(buf)
+					res := string(buf[:n])
+					t.Errorf(`%s:%d:%d: expected Done()==true, found segment "%s"`, name, i, j, res)
+				}
+				continue
+			}
+			if iter.Done() {
+				t.Errorf("%s:%d:%d: Done()==true, want false", name, i, j)
+			}
+			n := iter.Next(buf)
+			seg = f.String(seg)
+			if res := string(buf[:n]); res != seg {
+				t.Errorf(`%s:%d:%d" segment was "%s" (%d); want "%s" (%d)`, name, i, j, res, len(res), seg, len(seg))
+			}
+		}
+	}
+}
diff --git a/libgo/go/exp/norm/normalize.go b/libgo/go/exp/norm/normalize.go
index 030d900..b5cd44a 100644
--- a/libgo/go/exp/norm/normalize.go
+++ b/libgo/go/exp/norm/normalize.go
@@ -243,7 +243,7 @@ func quickSpan(rb *reorderBuffer, i int) int {
 	lastSegStart := i
 	src, n := rb.src, rb.nsrc
 	for i < n {
-		if j := src.skipASCII(i); i != j {
+		if j := src.skipASCII(i, n); i != j {
 			i = j
 			lastSegStart = i - 1
 			lastCC = 0
@@ -448,11 +448,16 @@ func decomposeToLastBoundary(rb *reorderBuffer, buf []byte) []byte {
 		}
 		// Check that decomposition doesn't result in overflow.
 		if info.hasDecomposition() {
-			dcomp := info.decomposition()
-			for i := 0; i < len(dcomp); {
-				inf := rb.f.info(inputBytes(dcomp), i)
-				i += int(inf.size)
+			if isHangul(buf) {
+				i += int(info.size)
 				n++
+			} else {
+				dcomp := info.decomposition()
+				for i := 0; i < len(dcomp); {
+					inf := rb.f.info(inputBytes(dcomp), i)
+					i += int(inf.size)
+					n++
+				}
 			}
 		} else {
 			n++
diff --git a/libgo/go/exp/norm/normalize_test.go b/libgo/go/exp/norm/normalize_test.go
index c7d5e08..8b97059 100644
--- a/libgo/go/exp/norm/normalize_test.go
+++ b/libgo/go/exp/norm/normalize_test.go
@@ -5,6 +5,7 @@
 package norm
 
 import (
+	"bytes"
 	"strings"
 	"testing"
 )
@@ -495,15 +496,40 @@ func TestAppend(t *testing.T) {
 	runAppendTests(t, "TestString", NFKC, stringF, appendTests)
 }
 
+func appendBench(f Form, in []byte) func() {
+	buf := make([]byte, 0, 4*len(in))
+	return func() {
+		f.Append(buf, in...)
+	}
+}
+
+func iterBench(f Form, in []byte) func() {
+	buf := make([]byte, 4*len(in))
+	iter := Iter{}
+	return func() {
+		iter.SetInput(f, in)
+		for !iter.Done() {
+			iter.Next(buf)
+		}
+	}
+}
+
+func appendBenchmarks(bm []func(), f Form, in []byte) []func() {
+	//bm = append(bm, appendBench(f, in))
+	bm = append(bm, iterBench(f, in))
+	return bm
+}
+
 func doFormBenchmark(b *testing.B, inf, f Form, s string) {
 	b.StopTimer()
 	in := inf.Bytes([]byte(s))
-	buf := make([]byte, 2*len(in))
-	b.SetBytes(int64(len(in)))
+	bm := appendBenchmarks(nil, f, in)
+	b.SetBytes(int64(len(in) * len(bm)))
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
-		buf = f.Append(buf[0:0], in...)
-		buf = buf[0:0]
+		for _, fn := range bm {
+			fn()
+		}
 	}
 }
 
@@ -549,17 +575,21 @@ func BenchmarkNormalizeHangulNFD2NFD(b *testing.B) {
 	doFormBenchmark(b, NFD, NFD, txt_kr)
 }
 
+var forms = []Form{NFC, NFD, NFKC, NFKD}
+
 func doTextBenchmark(b *testing.B, s string) {
 	b.StopTimer()
-	b.SetBytes(int64(len(s)) * 4)
 	in := []byte(s)
-	var buf = make([]byte, 0, 2*len(in))
+	bm := []func(){}
+	for _, f := range forms {
+		bm = appendBenchmarks(bm, f, in)
+	}
+	b.SetBytes(int64(len(s) * len(bm)))
 	b.StartTimer()
 	for i := 0; i < b.N; i++ {
-		NFC.Append(buf, in...)
-		NFD.Append(buf, in...)
-		NFKC.Append(buf, in...)
-		NFKD.Append(buf, in...)
+		for _, f := range bm {
+			f()
+		}
 	}
 }
 
@@ -584,6 +614,11 @@ func BenchmarkJapanese(b *testing.B) {
 func BenchmarkChinese(b *testing.B) {
 	doTextBenchmark(b, txt_cn)
 }
+func BenchmarkOverflow(b *testing.B) {
+	doTextBenchmark(b, overflow)
+}
+
+var overflow = string(bytes.Repeat([]byte("\u035D"), 4096)) + "\u035B"
 
 // Tests sampled from the Canonical ordering tests (Part 2) of
 // http://unicode.org/Public/UNIDATA/NormalizationTest.txt
diff --git a/libgo/go/exp/norm/normregtest.go b/libgo/go/exp/norm/normregtest.go
index c2ab25b..507de1a 100644
--- a/libgo/go/exp/norm/normregtest.go
+++ b/libgo/go/exp/norm/normregtest.go
@@ -220,6 +220,17 @@ func cmpIsNormal(t *Test, name string, f norm.Form, test string, result, want bo
 func doTest(t *Test, f norm.Form, gold, test string) {
 	result := f.Bytes([]byte(test))
 	cmpResult(t, "Bytes", f, gold, test, string(result))
+	sresult := f.String(test)
+	cmpResult(t, "String", f, gold, test, sresult)
+	buf := make([]byte, norm.MaxSegmentSize)
+	acc := []byte{}
+	i := norm.Iter{}
+	i.SetInputString(f, test)
+	for !i.Done() {
+		n := i.Next(buf)
+		acc = append(acc, buf[:n]...)
+	}
+	cmpResult(t, "Iter.Next", f, gold, test, string(acc))
 	for i := range test {
 		out := f.Append(f.Bytes([]byte(test[:i])), []byte(test[i:])...)
 		cmpResult(t, fmt.Sprintf(":Append:%d", i), f, gold, test, string(out))
diff --git a/libgo/go/exp/proxy/socks5.go b/libgo/go/exp/proxy/socks5.go
index 466e135..62fa5c9 100644
--- a/libgo/go/exp/proxy/socks5.go
+++ b/libgo/go/exp/proxy/socks5.go
@@ -98,9 +98,9 @@ func (s *socks5) Dial(network, addr string) (net.Conn, error) {
 
 	buf = append(buf, socks5Version)
 	if len(s.user) > 0 && len(s.user) < 256 && len(s.password) < 256 {
-		buf = append(buf, 2, /* num auth methods */ socks5AuthNone, socks5AuthPassword)
+		buf = append(buf, 2 /* num auth methods */, socks5AuthNone, socks5AuthPassword)
 	} else {
-		buf = append(buf, 1, /* num auth methods */ socks5AuthNone)
+		buf = append(buf, 1 /* num auth methods */, socks5AuthNone)
 	}
 
 	if _, err = conn.Write(buf); err != nil {
@@ -139,7 +139,7 @@ func (s *socks5) Dial(network, addr string) (net.Conn, error) {
 	}
 
 	buf = buf[:0]
-	buf = append(buf, socks5Version, socks5Connect, 0 /* reserved */ )
+	buf = append(buf, socks5Version, socks5Connect, 0 /* reserved */)
 
 	if ip := net.ParseIP(host); ip != nil {
 		if len(ip) == 4 {
diff --git a/libgo/go/exp/terminal/terminal.go b/libgo/go/exp/terminal/terminal.go
index c3ba5bd..c1ed0c0 100644
--- a/libgo/go/exp/terminal/terminal.go
+++ b/libgo/go/exp/terminal/terminal.go
@@ -389,12 +389,12 @@ func (t *Terminal) Write(buf []byte) (n int, err error) {
 
 	// We have a prompt and possibly user input on the screen. We
 	// have to clear it first.
-	t.move(0, /* up */ 0, /* down */ t.cursorX, /* left */ 0 /* right */ )
+	t.move(0 /* up */, 0 /* down */, t.cursorX /* left */, 0 /* right */)
 	t.cursorX = 0
 	t.clearLineToRight()
 
 	for t.cursorY > 0 {
-		t.move(1, /* up */ 0, 0, 0)
+		t.move(1 /* up */, 0, 0, 0)
 		t.cursorY--
 		t.clearLineToRight()
 	}
diff --git a/libgo/go/exp/winfsnotify/winfsnotify_test.go b/libgo/go/exp/winfsnotify/winfsnotify_test.go
index 59ac162..4a1929a 100644
--- a/libgo/go/exp/winfsnotify/winfsnotify_test.go
+++ b/libgo/go/exp/winfsnotify/winfsnotify_test.go
@@ -7,6 +7,7 @@
 package winfsnotify
 
 import (
+	"io/ioutil"
 	"os"
 	"testing"
 	"time"
@@ -115,7 +116,13 @@ func TestNotifyClose(t *testing.T) {
 		t.Fatal("double Close() test failed: second Close() call didn't return")
 	}
 
-	err := watcher.Watch("_test")
+	dir, err := ioutil.TempDir("", "wininotify")
+	if err != nil {
+		t.Fatalf("TempDir failed: %s", err)
+	}
+	defer os.RemoveAll(dir)
+
+	err = watcher.Watch(dir)
 	if err == nil {
 		t.Fatal("expected error on Watch() after Close(), got nil")
 	}