libgo: update to Go 1.8 release candidate 1

    
    Compiler changes:
      * Change map assignment to use mapassign and assign value directly.
      * Change string iteration to use decoderune, faster for ASCII strings.
      * Change makeslice to take int, and use makeslice64 for larger values.
      * Add new noverflow field to hmap struct used for maps.
    
    Unresolved problems, to be fixed later:
      * Commented out test in go/types/sizes_test.go that doesn't compile.
      * Commented out reflect.TestStructOf test for padding after zero-sized field.
    
    Reviewed-on: https://go-review.googlesource.com/35231

gotools/:
	Updates for Go 1.8rc1.
	* Makefile.am (go_cmd_go_files): Add bug.go.
	(s-zdefaultcc): Write defaultPkgConfig.
	* Makefile.in: Rebuild.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@244456 138bc75d-0d04-0410-961f-82ee72b054a4

13 files changed, 530 insertions, 136 deletions

diff --git a/libgo/go/time/example_test.go b/libgo/go/time/example_test.go
index 4170d5110d0..7dc2bb5e7ee 100644
--- a/libgo/go/time/example_test.go
+++ b/libgo/go/time/example_test.go
@@ -251,20 +251,18 @@ func ExampleTime_Truncate() {
 		2 * time.Second,
 		time.Minute,
 		10 * time.Minute,
-		time.Hour,
 	}
 
 	for _, d := range trunc {
-		fmt.Printf("t.Truncate(%6s) = %s\n", d, t.Truncate(d).Format("15:04:05.999999999"))
+		fmt.Printf("t.Truncate(%5s) = %s\n", d, t.Truncate(d).Format("15:04:05.999999999"))
 	}
 
 	// Output:
-	// t.Truncate(   1ns) = 12:15:30.918273645
-	// t.Truncate(   1µs) = 12:15:30.918273
-	// t.Truncate(   1ms) = 12:15:30.918
-	// t.Truncate(    1s) = 12:15:30
-	// t.Truncate(    2s) = 12:15:30
-	// t.Truncate(  1m0s) = 12:15:00
-	// t.Truncate( 10m0s) = 12:10:00
-	// t.Truncate(1h0m0s) = 12:00:00
+	// t.Truncate(  1ns) = 12:15:30.918273645
+	// t.Truncate(  1µs) = 12:15:30.918273
+	// t.Truncate(  1ms) = 12:15:30.918
+	// t.Truncate(   1s) = 12:15:30
+	// t.Truncate(   2s) = 12:15:30
+	// t.Truncate( 1m0s) = 12:15:00
+	// t.Truncate(10m0s) = 12:10:00
 }
diff --git a/libgo/go/time/export_android_test.go b/libgo/go/time/export_android_test.go
new file mode 100644
index 00000000000..fa6a058a73b
--- /dev/null
+++ b/libgo/go/time/export_android_test.go
@@ -0,0 +1,12 @@
+// Copyright 2016 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 time
+
+func ForceAndroidTzdataForTest(tzdata bool) {
+	tzdataPaths = origTzdataPaths
+	if tzdata {
+		tzdataPaths = tzdataPaths[:1]
+	}
+}
diff --git a/libgo/go/time/format.go b/libgo/go/time/format.go
index c2ae7930203..b903e1485c6 100644
--- a/libgo/go/time/format.go
+++ b/libgo/go/time/format.go
@@ -42,6 +42,13 @@ import "errors"
 //	Z07:00 Z or ±hh:mm
 //	Z07    Z or ±hh
 //
+// The recognized day of week formats are "Mon" and "Monday".
+// The recognized month formats are "Jan" and "January".
+//
+// Text in the format string that is not recognized as part of the reference
+// time is echoed verbatim during Format and expected to appear verbatim
+// in the input to Parse.
+//
 // The executable example for time.Format demonstrates the working
 // of the layout string in detail and is a good reference.
 //
@@ -844,6 +851,7 @@ func parse(layout, value string, defaultLocation, local *Location) (Time, error)
 			sec, value, err = getnum(value, std == stdZeroSecond)
 			if sec < 0 || 60 <= sec {
 				rangeErrString = "second"
+				break
 			}
 			// Special case: do we have a fractional second but no
 			// fractional second in the format?
@@ -1004,7 +1012,7 @@ func parse(layout, value string, defaultLocation, local *Location) (Time, error)
 	}
 
 	// Validate the day of the month.
-	if day > daysIn(Month(month), year) {
+	if day < 1 || day > daysIn(Month(month), year) {
 		return Time{}, &ParseError{alayout, avalue, "", value, ": day out of range"}
 	}
 
@@ -1020,12 +1028,12 @@ func parse(layout, value string, defaultLocation, local *Location) (Time, error)
 		// If that zone was in effect at the given time, use it.
 		name, offset, _, _, _ := local.lookup(t.sec + internalToUnix)
 		if offset == zoneOffset && (zoneName == "" || name == zoneName) {
-			t.loc = local
+			t.setLoc(local)
 			return t, nil
 		}
 
 		// Otherwise create fake zone to record offset.
-		t.loc = FixedZone(zoneName, zoneOffset)
+		t.setLoc(FixedZone(zoneName, zoneOffset))
 		return t, nil
 	}
 
@@ -1036,7 +1044,7 @@ func parse(layout, value string, defaultLocation, local *Location) (Time, error)
 		offset, _, ok := local.lookupName(zoneName, t.sec+internalToUnix)
 		if ok {
 			t.sec -= int64(offset)
-			t.loc = local
+			t.setLoc(local)
 			return t, nil
 		}
 
@@ -1045,7 +1053,7 @@ func parse(layout, value string, defaultLocation, local *Location) (Time, error)
 			offset, _ = atoi(zoneName[3:]) // Guaranteed OK by parseGMT.
 			offset *= 3600
 		}
-		t.loc = FixedZone(zoneName, offset)
+		t.setLoc(FixedZone(zoneName, offset))
 		return t, nil
 	}
 
@@ -1093,8 +1101,9 @@ func parseTimeZone(value string) (length int, ok bool) {
 		if value[4] == 'T' {
 			return 5, true
 		}
-	case 4: // Must end in T to match.
-		if value[3] == 'T' {
+	case 4:
+		// Must end in T, except one special case.
+		if value[3] == 'T' || value[:4] == "WITA" {
 			return 4, true
 		}
 	case 3:
@@ -1173,6 +1182,37 @@ func leadingInt(s string) (x int64, rem string, err error) {
 	return x, s[i:], nil
 }
 
+// leadingFraction consumes the leading [0-9]* from s.
+// It is used only for fractions, so does not return an error on overflow,
+// it just stops accumulating precision.
+func leadingFraction(s string) (x int64, scale float64, rem string) {
+	i := 0
+	scale = 1
+	overflow := false
+	for ; i < len(s); i++ {
+		c := s[i]
+		if c < '0' || c > '9' {
+			break
+		}
+		if overflow {
+			continue
+		}
+		if x > (1<<63-1)/10 {
+			// It's possible for overflow to give a positive number, so take care.
+			overflow = true
+			continue
+		}
+		y := x*10 + int64(c) - '0'
+		if y < 0 {
+			overflow = true
+			continue
+		}
+		x = y
+		scale *= 10
+	}
+	return x, scale, s[i:]
+}
+
 var unitMap = map[string]int64{
 	"ns": int64(Nanosecond),
 	"us": int64(Microsecond),
@@ -1235,13 +1275,7 @@ func ParseDuration(s string) (Duration, error) {
 		if s != "" && s[0] == '.' {
 			s = s[1:]
 			pl := len(s)
-			f, s, err = leadingInt(s)
-			if err != nil {
-				return 0, errors.New("time: invalid duration " + orig)
-			}
-			for n := pl - len(s); n > 0; n-- {
-				scale *= 10
-			}
+			f, scale, s = leadingFraction(s)
 			post = pl != len(s)
 		}
 		if !pre && !post {
diff --git a/libgo/go/time/format_test.go b/libgo/go/time/format_test.go
index ed5509b3021..648ead0886c 100644
--- a/libgo/go/time/format_test.go
+++ b/libgo/go/time/format_test.go
@@ -224,6 +224,7 @@ var dayOutOfRangeTests = []struct {
 	{"Thu Nov 31 21:00:57 2010", false},
 	{"Thu Dec 31 21:00:57 2010", true},
 	{"Thu Dec 32 21:00:57 2010", false},
+	{"Thu Dec 00 21:00:57 2010", false},
 }
 
 func TestParseDayOutOfRange(t *testing.T) {
@@ -406,6 +407,7 @@ var parseTimeZoneTests = []ParseTimeZoneTest{
 	{"ESAST hi", 5, true},
 	{"ESASTT hi", 0, false}, // run of upper-case letters too long.
 	{"ESATY hi", 0, false},  // five letters must end in T.
+	{"WITA hi", 4, true},    // Issue #18251
 }
 
 func TestParseTimeZone(t *testing.T) {
@@ -442,6 +444,8 @@ var parseErrorTests = []ParseErrorTest{
 	{RFC3339, "2006-01-02T15:04_abc", `parsing time "2006-01-02T15:04_abc" as "2006-01-02T15:04:05Z07:00": cannot parse "_abc" as ":"`},
 	{RFC3339, "2006-01-02T15:04:05_abc", `parsing time "2006-01-02T15:04:05_abc" as "2006-01-02T15:04:05Z07:00": cannot parse "_abc" as "Z07:00"`},
 	{RFC3339, "2006-01-02T15:04:05Z_abc", `parsing time "2006-01-02T15:04:05Z_abc": extra text: _abc`},
+	// invalid second followed by optional fractional seconds
+	{RFC3339, "2010-02-04T21:00:67.012345678-08:00", "second out of range"},
 }
 
 func TestParseErrors(t *testing.T) {
diff --git a/libgo/go/time/sleep.go b/libgo/go/time/sleep.go
index 73114f5eecd..4b01404896e 100644
--- a/libgo/go/time/sleep.go
+++ b/libgo/go/time/sleep.go
@@ -12,7 +12,7 @@ func Sleep(d Duration)
 func runtimeNano() int64
 
 // Interface to timers implemented in package runtime.
-// Must be in sync with ../runtime/runtime.h:/^struct.Timer$
+// Must be in sync with ../runtime/time.go:/^type timer
 type runtimeTimer struct {
 	i      int
 	when   int64
@@ -55,13 +55,22 @@ type Timer struct {
 // Stop does not close the channel, to prevent a read from the channel succeeding
 // incorrectly.
 //
-// To prevent the timer firing after a call to Stop,
-// check the return value and drain the channel. For example:
+// To prevent a timer created with NewTimer from firing after a call to Stop,
+// check the return value and drain the channel.
+// For example, assuming the program has not received from t.C already:
+//
 // 	if !t.Stop() {
 // 		<-t.C
 // 	}
+//
 // This cannot be done concurrent to other receives from the Timer's
 // channel.
+//
+// For a timer created with AfterFunc(d, f), if t.Stop returns false, then the timer
+// has already expired and the function f has been started in its own goroutine;
+// Stop does not wait for f to complete before returning.
+// If the caller needs to know whether f is completed, it must coordinate
+// with f explicitly.
 func (t *Timer) Stop() bool {
 	if t.r.f == nil {
 		panic("time: Stop called on uninitialized Timer")
@@ -89,18 +98,25 @@ func NewTimer(d Duration) *Timer {
 // It returns true if the timer had been active, false if the timer had
 // expired or been stopped.
 //
-// To reuse an active timer, always call its Stop method first and—if it had
-// expired—drain the value from its channel. For example:
+// Resetting a timer must take care not to race with the send into t.C
+// that happens when the current timer expires.
+// If a program has already received a value from t.C, the timer is known
+// to have expired, and t.Reset can be used directly.
+// If a program has not yet received a value from t.C, however,
+// the timer must be stopped and—if Stop reports that the timer expired
+// before being stopped—the channel explicitly drained:
+//
 // 	if !t.Stop() {
 // 		<-t.C
 // 	}
 // 	t.Reset(d)
+//
 // This should not be done concurrent to other receives from the Timer's
 // channel.
 //
 // Note that it is not possible to use Reset's return value correctly, as there
 // is a race condition between draining the channel and the new timer expiring.
-// Reset should always be used in concert with Stop, as described above.
+// Reset should always be invoked on stopped or expired channels, as described above.
 // The return value exists to preserve compatibility with existing programs.
 func (t *Timer) Reset(d Duration) bool {
 	if t.r.f == nil {
diff --git a/libgo/go/time/time.go b/libgo/go/time/time.go
index c31de357d58..10b32461e1c 100644
--- a/libgo/go/time/time.go
+++ b/libgo/go/time/time.go
@@ -4,7 +4,8 @@
 
 // Package time provides functionality for measuring and displaying time.
 //
-// The calendrical calculations always assume a Gregorian calendar.
+// The calendrical calculations always assume a Gregorian calendar, with
+// no leap seconds.
 package time
 
 import "errors"
@@ -49,11 +50,18 @@ type Time struct {
 	// loc specifies the Location that should be used to
 	// determine the minute, hour, month, day, and year
 	// that correspond to this Time.
-	// Only the zero Time has a nil Location.
-	// In that case it is interpreted to mean UTC.
+	// The nil location means UTC.
+	// All UTC times are represented with loc==nil, never loc==&utcLoc.
 	loc *Location
 }
 
+func (t *Time) setLoc(loc *Location) {
+	if loc == &utcLoc {
+		loc = nil
+	}
+	t.loc = loc
+}
+
 // After reports whether the time instant t is after u.
 func (t Time) After(u Time) bool {
 	return t.sec > u.sec || t.sec == u.sec && t.nsec > u.nsec
@@ -67,8 +75,7 @@ func (t Time) Before(u Time) bool {
 // Equal reports whether t and u represent the same time instant.
 // Two times can be equal even if they are in different locations.
 // For example, 6:00 +0200 CEST and 4:00 UTC are Equal.
-// This comparison is different from using t == u, which also compares
-// the locations.
+// Do not use == with Time values.
 func (t Time) Equal(u Time) bool {
 	return t.sec == u.sec && t.nsec == u.nsec
 }
@@ -107,7 +114,14 @@ var months = [...]string{
 }
 
 // String returns the English name of the month ("January", "February", ...).
-func (m Month) String() string { return months[m-1] }
+func (m Month) String() string {
+	if January <= m && m <= December {
+		return months[m-1]
+	}
+	buf := make([]byte, 20)
+	n := fmtInt(buf, uint64(m))
+	return "%!Month(" + string(buf[n:]) + ")"
+}
 
 // A Weekday specifies a day of the week (Sunday = 0, ...).
 type Weekday int
@@ -585,21 +599,21 @@ func (d Duration) Nanoseconds() int64 { return int64(d) }
 func (d Duration) Seconds() float64 {
 	sec := d / Second
 	nsec := d % Second
-	return float64(sec) + float64(nsec)*1e-9
+	return float64(sec) + float64(nsec)/1e9
 }
 
 // Minutes returns the duration as a floating point number of minutes.
 func (d Duration) Minutes() float64 {
 	min := d / Minute
 	nsec := d % Minute
-	return float64(min) + float64(nsec)*(1e-9/60)
+	return float64(min) + float64(nsec)/(60*1e9)
 }
 
 // Hours returns the duration as a floating point number of hours.
 func (d Duration) Hours() float64 {
 	hour := d / Hour
 	nsec := d % Hour
-	return float64(hour) + float64(nsec)*(1e-9/60/60)
+	return float64(hour) + float64(nsec)/(60*60*1e9)
 }
 
 // Add returns the time t+d.
@@ -640,6 +654,12 @@ func Since(t Time) Duration {
 	return Now().Sub(t)
 }
 
+// Until returns the duration until t.
+// It is shorthand for t.Sub(time.Now()).
+func Until(t Time) Duration {
+	return t.Sub(Now())
+}
+
 // AddDate returns the time corresponding to adding the
 // given number of years, months, and days to t.
 // For example, AddDate(-1, 2, 3) applied to January 1, 2011
@@ -651,7 +671,7 @@ func Since(t Time) Duration {
 func (t Time) AddDate(years int, months int, days int) Time {
 	year, month, day := t.Date()
 	hour, min, sec := t.Clock()
-	return Date(year+years, month+Month(months), day+days, hour, min, sec, int(t.nsec), t.loc)
+	return Date(year+years, month+Month(months), day+days, hour, min, sec, int(t.nsec), t.Location())
 }
 
 const (
@@ -781,13 +801,13 @@ func Now() Time {
 
 // UTC returns t with the location set to UTC.
 func (t Time) UTC() Time {
-	t.loc = UTC
+	t.setLoc(&utcLoc)
 	return t
 }
 
 // Local returns t with the location set to local time.
 func (t Time) Local() Time {
-	t.loc = Local
+	t.setLoc(Local)
 	return t
 }
 
@@ -798,7 +818,7 @@ func (t Time) In(loc *Location) Time {
 	if loc == nil {
 		panic("time: missing Location in call to Time.In")
 	}
-	t.loc = loc
+	t.setLoc(loc)
 	return t
 }
 
@@ -826,8 +846,9 @@ func (t Time) Unix() int64 {
 
 // UnixNano returns t as a Unix time, the number of nanoseconds elapsed
 // since January 1, 1970 UTC. The result is undefined if the Unix time
-// in nanoseconds cannot be represented by an int64. Note that this
-// means the result of calling UnixNano on the zero Time is undefined.
+// in nanoseconds cannot be represented by an int64 (a date before the year
+// 1678 or after 2262). Note that this means the result of calling UnixNano
+// on the zero Time is undefined.
 func (t Time) UnixNano() int64 {
 	return (t.sec+internalToUnix)*1e9 + int64(t.nsec)
 }
@@ -838,7 +859,7 @@ const timeBinaryVersion byte = 1
 func (t Time) MarshalBinary() ([]byte, error) {
 	var offsetMin int16 // minutes east of UTC. -1 is UTC.
 
-	if t.Location() == &utcLoc {
+	if t.Location() == UTC {
 		offsetMin = -1
 	} else {
 		_, offset := t.Zone()
@@ -899,11 +920,11 @@ func (t *Time) UnmarshalBinary(data []byte) error {
 	offset := int(int16(buf[1])|int16(buf[0])<<8) * 60
 
 	if offset == -1*60 {
-		t.loc = &utcLoc
+		t.setLoc(&utcLoc)
 	} else if _, localoff, _, _, _ := Local.lookup(t.sec + internalToUnix); offset == localoff {
-		t.loc = Local
+		t.setLoc(Local)
 	} else {
-		t.loc = FixedZone("", offset)
+		t.setLoc(FixedZone("", offset))
 	}
 
 	return nil
@@ -942,6 +963,10 @@ func (t Time) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON implements the json.Unmarshaler interface.
 // The time is expected to be a quoted string in RFC 3339 format.
 func (t *Time) UnmarshalJSON(data []byte) error {
+	// Ignore null, like in the main JSON package.
+	if string(data) == "null" {
+		return nil
+	}
 	// Fractional seconds are handled implicitly by Parse.
 	var err error
 	*t, err = Parse(`"`+RFC3339+`"`, string(data))
@@ -1092,11 +1117,18 @@ func Date(year int, month Month, day, hour, min, sec, nsec int, loc *Location) T
 		unix -= int64(offset)
 	}
 
-	return Time{unix + unixToInternal, int32(nsec), loc}
+	t := Time{unix + unixToInternal, int32(nsec), nil}
+	t.setLoc(loc)
+	return t
 }
 
 // Truncate returns the result of rounding t down to a multiple of d (since the zero time).
 // If d <= 0, Truncate returns t unchanged.
+//
+// Truncate operates on the time as an absolute duration since the
+// zero time; it does not operate on the presentation form of the
+// time. Thus, Truncate(Hour) may return a time with a non-zero
+// minute, depending on the time's Location.
 func (t Time) Truncate(d Duration) Time {
 	if d <= 0 {
 		return t
@@ -1108,6 +1140,11 @@ func (t Time) Truncate(d Duration) Time {
 // Round returns the result of rounding t to the nearest multiple of d (since the zero time).
 // The rounding behavior for halfway values is to round up.
 // If d <= 0, Round returns t unchanged.
+//
+// Round operates on the time as an absolute duration since the
+// zero time; it does not operate on the presentation form of the
+// time. Thus, Round(Hour) may return a time with a non-zero
+// minute, depending on the time's Location.
 func (t Time) Round(d Duration) Time {
 	if d <= 0 {
 		return t
diff --git a/libgo/go/time/time_test.go b/libgo/go/time/time_test.go
index c9665ea04b5..2922560f097 100644
--- a/libgo/go/time/time_test.go
+++ b/libgo/go/time/time_test.go
@@ -840,6 +840,10 @@ var parseDurationTests = []struct {
 	{"9223372036s854ms775us807ns", true, (1<<63 - 1) * Nanosecond},
 	// large negative value
 	{"-9223372036854775807ns", true, -1<<63 + 1*Nanosecond},
+	// huge string; issue 15011.
+	{"0.100000000000000000000h", true, 6 * Minute},
+	// This value tests the first overflow check in leadingFraction.
+	{"0.830103483285477580700h", true, 49*Minute + 48*Second + 372539827*Nanosecond},
 
 	// errors
 	{"", false, 0},
@@ -891,7 +895,7 @@ func TestLocationRace(t *testing.T) {
 	go func() {
 		c <- Now().String()
 	}()
-	Now().String()
+	_ = Now().String()
 	<-c
 	Sleep(100 * Millisecond)
 
@@ -999,6 +1003,21 @@ func TestDurationNanoseconds(t *testing.T) {
 	}
 }
 
+var secDurationTests = []struct {
+	d    Duration
+	want float64
+}{
+	{Duration(300000000), 0.3},
+}
+
+func TestDurationSeconds(t *testing.T) {
+	for _, tt := range secDurationTests {
+		if got := tt.d.Seconds(); got != tt.want {
+			t.Errorf("d.Seconds() = %g; want: %g", got, tt.want)
+		}
+	}
+}
+
 var minDurationTests = []struct {
 	d    Duration
 	want float64
@@ -1007,6 +1026,7 @@ var minDurationTests = []struct {
 	{Duration(-1), -1 / 60e9},
 	{Duration(1), 1 / 60e9},
 	{Duration(60000000000), 1},
+	{Duration(3000), 5e-8},
 }
 
 func TestDurationMinutes(t *testing.T) {
@@ -1025,6 +1045,7 @@ var hourDurationTests = []struct {
 	{Duration(-1), -1 / 3600e9},
 	{Duration(1), 1 / 3600e9},
 	{Duration(3600000000000), 1},
+	{Duration(36), 1e-11},
 }
 
 func TestDurationHours(t *testing.T) {
@@ -1035,6 +1056,100 @@ func TestDurationHours(t *testing.T) {
 	}
 }
 
+var defaultLocTests = []struct {
+	name string
+	f    func(t1, t2 Time) bool
+}{
+	{"After", func(t1, t2 Time) bool { return t1.After(t2) == t2.After(t1) }},
+	{"Before", func(t1, t2 Time) bool { return t1.Before(t2) == t2.Before(t1) }},
+	{"Equal", func(t1, t2 Time) bool { return t1.Equal(t2) == t2.Equal(t1) }},
+
+	{"IsZero", func(t1, t2 Time) bool { return t1.IsZero() == t2.IsZero() }},
+	{"Date", func(t1, t2 Time) bool {
+		a1, b1, c1 := t1.Date()
+		a2, b2, c2 := t2.Date()
+		return a1 == a2 && b1 == b2 && c1 == c2
+	}},
+	{"Year", func(t1, t2 Time) bool { return t1.Year() == t2.Year() }},
+	{"Month", func(t1, t2 Time) bool { return t1.Month() == t2.Month() }},
+	{"Day", func(t1, t2 Time) bool { return t1.Day() == t2.Day() }},
+	{"Weekday", func(t1, t2 Time) bool { return t1.Weekday() == t2.Weekday() }},
+	{"ISOWeek", func(t1, t2 Time) bool {
+		a1, b1 := t1.ISOWeek()
+		a2, b2 := t2.ISOWeek()
+		return a1 == a2 && b1 == b2
+	}},
+	{"Clock", func(t1, t2 Time) bool {
+		a1, b1, c1 := t1.Clock()
+		a2, b2, c2 := t2.Clock()
+		return a1 == a2 && b1 == b2 && c1 == c2
+	}},
+	{"Hour", func(t1, t2 Time) bool { return t1.Hour() == t2.Hour() }},
+	{"Minute", func(t1, t2 Time) bool { return t1.Minute() == t2.Minute() }},
+	{"Second", func(t1, t2 Time) bool { return t1.Second() == t2.Second() }},
+	{"Nanosecond", func(t1, t2 Time) bool { return t1.Hour() == t2.Hour() }},
+	{"YearDay", func(t1, t2 Time) bool { return t1.YearDay() == t2.YearDay() }},
+
+	// Using Equal since Add don't modify loc using "==" will cause a fail
+	{"Add", func(t1, t2 Time) bool { return t1.Add(Hour).Equal(t2.Add(Hour)) }},
+	{"Sub", func(t1, t2 Time) bool { return t1.Sub(t2) == t2.Sub(t1) }},
+
+	//Original caus for this test case bug 15852
+	{"AddDate", func(t1, t2 Time) bool { return t1.AddDate(1991, 9, 3) == t2.AddDate(1991, 9, 3) }},
+
+	{"UTC", func(t1, t2 Time) bool { return t1.UTC() == t2.UTC() }},
+	{"Local", func(t1, t2 Time) bool { return t1.Local() == t2.Local() }},
+	{"In", func(t1, t2 Time) bool { return t1.In(UTC) == t2.In(UTC) }},
+
+	{"Local", func(t1, t2 Time) bool { return t1.Local() == t2.Local() }},
+	{"Zone", func(t1, t2 Time) bool {
+		a1, b1 := t1.Zone()
+		a2, b2 := t2.Zone()
+		return a1 == a2 && b1 == b2
+	}},
+
+	{"Unix", func(t1, t2 Time) bool { return t1.Unix() == t2.Unix() }},
+	{"UnixNano", func(t1, t2 Time) bool { return t1.UnixNano() == t2.UnixNano() }},
+
+	{"MarshalBinary", func(t1, t2 Time) bool {
+		a1, b1 := t1.MarshalBinary()
+		a2, b2 := t2.MarshalBinary()
+		return bytes.Equal(a1, a2) && b1 == b2
+	}},
+	{"GobEncode", func(t1, t2 Time) bool {
+		a1, b1 := t1.GobEncode()
+		a2, b2 := t2.GobEncode()
+		return bytes.Equal(a1, a2) && b1 == b2
+	}},
+	{"MarshalJSON", func(t1, t2 Time) bool {
+		a1, b1 := t1.MarshalJSON()
+		a2, b2 := t2.MarshalJSON()
+		return bytes.Equal(a1, a2) && b1 == b2
+	}},
+	{"MarshalText", func(t1, t2 Time) bool {
+		a1, b1 := t1.MarshalText()
+		a2, b2 := t2.MarshalText()
+		return bytes.Equal(a1, a2) && b1 == b2
+	}},
+
+	{"Truncate", func(t1, t2 Time) bool { return t1.Truncate(Hour).Equal(t2.Truncate(Hour)) }},
+	{"Round", func(t1, t2 Time) bool { return t1.Round(Hour).Equal(t2.Round(Hour)) }},
+
+	{"== Time{}", func(t1, t2 Time) bool { return (t1 == Time{}) == (t2 == Time{}) }},
+}
+
+func TestDefaultLoc(t *testing.T) {
+	//This test verifyes that all Time's methods behaves identical if loc is set
+	//as nil or UTC
+	for _, tt := range defaultLocTests {
+		t1 := Time{}
+		t2 := Time{}.UTC()
+		if !tt.f(t1, t2) {
+			t.Errorf("Time{} and Time{}.UTC() behave differently for %s", tt.name)
+		}
+	}
+}
+
 func BenchmarkNow(b *testing.B) {
 	for i := 0; i < b.N; i++ {
 		t = Now()
@@ -1117,3 +1232,25 @@ func BenchmarkDay(b *testing.B) {
 		_ = t.Day()
 	}
 }
+
+func TestMarshalBinaryZeroTime(t *testing.T) {
+	t0 := Time{}
+	enc, err := t0.MarshalBinary()
+	if err != nil {
+		t.Fatal(err)
+	}
+	t1 := Now() // not zero
+	if err := t1.UnmarshalBinary(enc); err != nil {
+		t.Fatal(err)
+	}
+	if t1 != t0 {
+		t.Errorf("t0=%#v\nt1=%#v\nwant identical structures", t0, t1)
+	}
+}
+
+// Issue 17720: Zero value of time.Month fails to print
+func TestZeroMonthString(t *testing.T) {
+	if got, want := Month(0).String(), "%!Month(0)"; got != want {
+		t.Errorf("zero month = %q; want %q", got, want)
+	}
+}
diff --git a/libgo/go/time/zoneinfo.go b/libgo/go/time/zoneinfo.go
index c56743933f9..fb0aa392404 100644
--- a/libgo/go/time/zoneinfo.go
+++ b/libgo/go/time/zoneinfo.go
@@ -9,6 +9,8 @@ import (
 	"syscall"
 )
 
+//go:generate env ZONEINFO=$GOROOT/lib/time/zoneinfo.zip go run genzabbrs.go -output zoneinfo_abbrs_windows.go
+
 // A Location maps time instants to the zone in use at that time.
 // Typically, the Location represents the collection of time offsets
 // in use in a geographical area, such as CEST and CET for central Europe.
diff --git a/libgo/go/time/zoneinfo_abbrs_windows.go b/libgo/go/time/zoneinfo_abbrs_windows.go
index 344a891d1a4..9425db844ca 100644
--- a/libgo/go/time/zoneinfo_abbrs_windows.go
+++ b/libgo/go/time/zoneinfo_abbrs_windows.go
@@ -13,92 +13,106 @@ type abbr struct {
 }
 
 var abbrs = map[string]abbr{
-	"Egypt Standard Time":             {"EET", "EET"},    // Africa/Cairo
-	"Morocco Standard Time":           {"WET", "WEST"},   // Africa/Casablanca
-	"South Africa Standard Time":      {"SAST", "SAST"},  // Africa/Johannesburg
-	"W. Central Africa Standard Time": {"WAT", "WAT"},    // Africa/Lagos
-	"E. Africa Standard Time":         {"EAT", "EAT"},    // Africa/Nairobi
-	"Libya Standard Time":             {"EET", "EET"},    // Africa/Tripoli
-	"Namibia Standard Time":           {"WAT", "WAST"},   // Africa/Windhoek
-	"Alaskan Standard Time":           {"AKST", "AKDT"},  // America/Anchorage
-	"Paraguay Standard Time":          {"PYT", "PYST"},   // America/Asuncion
-	"Bahia Standard Time":             {"BRT", "BRT"},    // America/Bahia
-	"SA Pacific Standard Time":        {"COT", "COT"},    // America/Bogota
-	"Argentina Standard Time":         {"ART", "ART"},    // America/Buenos_Aires
-	"Eastern Standard Time (Mexico)":  {"EST", "EST"},    // America/Cancun
-	"Venezuela Standard Time":         {"VET", "VET"},    // America/Caracas
-	"SA Eastern Standard Time":        {"GFT", "GFT"},    // America/Cayenne
-	"Central Standard Time":           {"CST", "CDT"},    // America/Chicago
-	"Mountain Standard Time (Mexico)": {"MST", "MDT"},    // America/Chihuahua
-	"Central Brazilian Standard Time": {"AMT", "AMST"},   // America/Cuiaba
-	"Mountain Standard Time":          {"MST", "MDT"},    // America/Denver
-	"Greenland Standard Time":         {"WGT", "WGST"},   // America/Godthab
-	"Central America Standard Time":   {"CST", "CST"},    // America/Guatemala
-	"Atlantic Standard Time":          {"AST", "ADT"},    // America/Halifax
-	"US Eastern Standard Time":        {"EST", "EDT"},    // America/Indianapolis
-	"SA Western Standard Time":        {"BOT", "BOT"},    // America/La_Paz
-	"Pacific Standard Time":           {"PST", "PDT"},    // America/Los_Angeles
-	"Central Standard Time (Mexico)":  {"CST", "CDT"},    // America/Mexico_City
-	"Montevideo Standard Time":        {"UYT", "UYT"},    // America/Montevideo
-	"Eastern Standard Time":           {"EST", "EDT"},    // America/New_York
-	"US Mountain Standard Time":       {"MST", "MST"},    // America/Phoenix
-	"Canada Central Standard Time":    {"CST", "CST"},    // America/Regina
-	"Pacific SA Standard Time":        {"CLT", "CLST"},   // America/Santiago
-	"E. South America Standard Time":  {"BRT", "BRST"},   // America/Sao_Paulo
-	"Newfoundland Standard Time":      {"NST", "NDT"},    // America/St_Johns
-	"Central Asia Standard Time":      {"+06", "+06"},    // Asia/Almaty
-	"Jordan Standard Time":            {"EET", "EEST"},   // Asia/Amman
-	"Arabic Standard Time":            {"AST", "AST"},    // Asia/Baghdad
-	"Azerbaijan Standard Time":        {"AZT", "AZT"},    // Asia/Baku
-	"SE Asia Standard Time":           {"ICT", "ICT"},    // Asia/Bangkok
-	"Altai Standard Time":             {"+06", "+07"},    // Asia/Barnaul
-	"Middle East Standard Time":       {"EET", "EEST"},   // Asia/Beirut
-	"India Standard Time":             {"IST", "IST"},    // Asia/Calcutta
-	"Transbaikal Standard Time":       {"IRKT", "YAKT"},  // Asia/Chita
-	"Sri Lanka Standard Time":         {"IST", "IST"},    // Asia/Colombo
-	"Syria Standard Time":             {"EET", "EEST"},   // Asia/Damascus
-	"Bangladesh Standard Time":        {"BDT", "BDT"},    // Asia/Dhaka
-	"Arabian Standard Time":           {"GST", "GST"},    // Asia/Dubai
-	"North Asia East Standard Time":   {"IRKT", "IRKT"},  // Asia/Irkutsk
-	"Israel Standard Time":            {"IST", "IDT"},    // Asia/Jerusalem
-	"Afghanistan Standard Time":       {"AFT", "AFT"},    // Asia/Kabul
-	"Russia Time Zone 11":             {"PETT", "PETT"},  // Asia/Kamchatka
-	"Pakistan Standard Time":          {"PKT", "PKT"},    // Asia/Karachi
-	"Nepal Standard Time":             {"NPT", "NPT"},    // Asia/Katmandu
-	"North Asia Standard Time":        {"KRAT", "KRAT"},  // Asia/Krasnoyarsk
-	"Magadan Standard Time":           {"MAGT", "MAGT"},  // Asia/Magadan
-	"N. Central Asia Standard Time":   {"NOVT", "NOVT"},  // Asia/Novosibirsk
-	"North Korea Standard Time":       {"KST", "KST"},    // Asia/Pyongyang
-	"Myanmar Standard Time":           {"MMT", "MMT"},    // Asia/Rangoon
-	"Arab Standard Time":              {"AST", "AST"},    // Asia/Riyadh
-	"Sakhalin Standard Time":          {"SAKT", "SAKT"},  // Asia/Sakhalin
-	"Korea Standard Time":             {"KST", "KST"},    // Asia/Seoul
-	"China Standard Time":             {"CST", "CST"},    // Asia/Shanghai
-	"Singapore Standard Time":         {"SGT", "SGT"},    // Asia/Singapore
-	"Russia Time Zone 10":             {"SRET", "SRET"},  // Asia/Srednekolymsk
-	"Taipei Standard Time":            {"CST", "CST"},    // Asia/Taipei
-	"West Asia Standard Time":         {"UZT", "UZT"},    // Asia/Tashkent
-	"Georgian Standard Time":          {"GET", "GET"},    // Asia/Tbilisi
-	"Iran Standard Time":              {"IRST", "IRDT"},  // Asia/Tehran
-	"Tokyo Standard Time":             {"JST", "JST"},    // Asia/Tokyo
-	"Ulaanbaatar Standard Time":       {"ULAT", "ULAST"}, // Asia/Ulaanbaatar
-	"Vladivostok Standard Time":       {"VLAT", "VLAT"},  // Asia/Vladivostok
-	"Yakutsk Standard Time":           {"YAKT", "YAKT"},  // Asia/Yakutsk
-	"Ekaterinburg Standard Time":      {"YEKT", "YEKT"},  // Asia/Yekaterinburg
-	"Caucasus Standard Time":          {"AMT", "AMT"},    // Asia/Yerevan
-	"Azores Standard Time":            {"AZOT", "AZOST"}, // Atlantic/Azores
-	"Cape Verde Standard Time":        {"CVT", "CVT"},    // Atlantic/Cape_Verde
-	"Greenwich Standard Time":         {"GMT", "GMT"},    // Atlantic/Reykjavik
-	"Cen. Australia Standard Time":    {"ACST", "ACDT"},  // Australia/Adelaide
-	"E. Australia Standard Time":      {"AEST", "AEST"},  // Australia/Brisbane
-	"AUS Central Standard Time":       {"ACST", "ACST"},  // Australia/Darwin
-	"Tasmania Standard Time":          {"AEST", "AEDT"},  // Australia/Hobart
-	"W. Australia Standard Time":      {"AWST", "AWST"},  // Australia/Perth
-	"AUS Eastern Standard Time":       {"AEST", "AEDT"},  // Australia/Sydney
+	"Egypt Standard Time":             {"EET", "EET"},     // Africa/Cairo
+	"Morocco Standard Time":           {"WET", "WEST"},    // Africa/Casablanca
+	"South Africa Standard Time":      {"SAST", "SAST"},   // Africa/Johannesburg
+	"W. Central Africa Standard Time": {"WAT", "WAT"},     // Africa/Lagos
+	"E. Africa Standard Time":         {"EAT", "EAT"},     // Africa/Nairobi
+	"Libya Standard Time":             {"EET", "EET"},     // Africa/Tripoli
+	"Namibia Standard Time":           {"WAT", "WAST"},    // Africa/Windhoek
+	"Aleutian Standard Time":          {"HST", "HDT"},     // America/Adak
+	"Alaskan Standard Time":           {"AKST", "AKDT"},   // America/Anchorage
+	"Tocantins Standard Time":         {"BRT", "BRT"},     // America/Araguaina
+	"Paraguay Standard Time":          {"PYT", "PYST"},    // America/Asuncion
+	"Bahia Standard Time":             {"BRT", "BRT"},     // America/Bahia
+	"SA Pacific Standard Time":        {"COT", "COT"},     // America/Bogota
+	"Argentina Standard Time":         {"ART", "ART"},     // America/Buenos_Aires
+	"Eastern Standard Time (Mexico)":  {"EST", "EST"},     // America/Cancun
+	"Venezuela Standard Time":         {"VET", "VET"},     // America/Caracas
+	"SA Eastern Standard Time":        {"GFT", "GFT"},     // America/Cayenne
+	"Central Standard Time":           {"CST", "CDT"},     // America/Chicago
+	"Mountain Standard Time (Mexico)": {"MST", "MDT"},     // America/Chihuahua
+	"Central Brazilian Standard Time": {"AMT", "AMST"},    // America/Cuiaba
+	"Mountain Standard Time":          {"MST", "MDT"},     // America/Denver
+	"Greenland Standard Time":         {"WGT", "WGST"},    // America/Godthab
+	"Turks And Caicos Standard Time":  {"AST", "AST"},     // America/Grand_Turk
+	"Central America Standard Time":   {"CST", "CST"},     // America/Guatemala
+	"Atlantic Standard Time":          {"AST", "ADT"},     // America/Halifax
+	"Cuba Standard Time":              {"CST", "CDT"},     // America/Havana
+	"US Eastern Standard Time":        {"EST", "EDT"},     // America/Indianapolis
+	"SA Western Standard Time":        {"BOT", "BOT"},     // America/La_Paz
+	"Pacific Standard Time":           {"PST", "PDT"},     // America/Los_Angeles
+	"Central Standard Time (Mexico)":  {"CST", "CDT"},     // America/Mexico_City
+	"Saint Pierre Standard Time":      {"PMST", "PMDT"},   // America/Miquelon
+	"Montevideo Standard Time":        {"UYT", "UYT"},     // America/Montevideo
+	"Eastern Standard Time":           {"EST", "EDT"},     // America/New_York
+	"US Mountain Standard Time":       {"MST", "MST"},     // America/Phoenix
+	"Haiti Standard Time":             {"EST", "EST"},     // America/Port-au-Prince
+	"Canada Central Standard Time":    {"CST", "CST"},     // America/Regina
+	"Pacific SA Standard Time":        {"CLT", "CLST"},    // America/Santiago
+	"E. South America Standard Time":  {"BRT", "BRST"},    // America/Sao_Paulo
+	"Newfoundland Standard Time":      {"NST", "NDT"},     // America/St_Johns
+	"Pacific Standard Time (Mexico)":  {"PST", "PDT"},     // America/Tijuana
+	"Central Asia Standard Time":      {"+06", "+06"},     // Asia/Almaty
+	"Jordan Standard Time":            {"EET", "EEST"},    // Asia/Amman
+	"Arabic Standard Time":            {"AST", "AST"},     // Asia/Baghdad
+	"Azerbaijan Standard Time":        {"AZT", "AZT"},     // Asia/Baku
+	"SE Asia Standard Time":           {"ICT", "ICT"},     // Asia/Bangkok
+	"Altai Standard Time":             {"+06", "+07"},     // Asia/Barnaul
+	"Middle East Standard Time":       {"EET", "EEST"},    // Asia/Beirut
+	"India Standard Time":             {"IST", "IST"},     // Asia/Calcutta
+	"Transbaikal Standard Time":       {"IRKT", "YAKT"},   // Asia/Chita
+	"Sri Lanka Standard Time":         {"IST", "IST"},     // Asia/Colombo
+	"Syria Standard Time":             {"EET", "EEST"},    // Asia/Damascus
+	"Bangladesh Standard Time":        {"BDT", "BDT"},     // Asia/Dhaka
+	"Arabian Standard Time":           {"GST", "GST"},     // Asia/Dubai
+	"West Bank Standard Time":         {"EET", "EEST"},    // Asia/Hebron
+	"W. Mongolia Standard Time":       {"HOVT", "HOVST"},  // Asia/Hovd
+	"North Asia East Standard Time":   {"IRKT", "IRKT"},   // Asia/Irkutsk
+	"Israel Standard Time":            {"IST", "IDT"},     // Asia/Jerusalem
+	"Afghanistan Standard Time":       {"AFT", "AFT"},     // Asia/Kabul
+	"Russia Time Zone 11":             {"PETT", "PETT"},   // Asia/Kamchatka
+	"Pakistan Standard Time":          {"PKT", "PKT"},     // Asia/Karachi
+	"Nepal Standard Time":             {"NPT", "NPT"},     // Asia/Katmandu
+	"North Asia Standard Time":        {"KRAT", "KRAT"},   // Asia/Krasnoyarsk
+	"Magadan Standard Time":           {"MAGT", "MAGT"},   // Asia/Magadan
+	"N. Central Asia Standard Time":   {"+06", "+07"},     // Asia/Novosibirsk
+	"North Korea Standard Time":       {"KST", "KST"},     // Asia/Pyongyang
+	"Myanmar Standard Time":           {"MMT", "MMT"},     // Asia/Rangoon
+	"Arab Standard Time":              {"AST", "AST"},     // Asia/Riyadh
+	"Sakhalin Standard Time":          {"SAKT", "SAKT"},   // Asia/Sakhalin
+	"Korea Standard Time":             {"KST", "KST"},     // Asia/Seoul
+	"China Standard Time":             {"CST", "CST"},     // Asia/Shanghai
+	"Singapore Standard Time":         {"SGT", "SGT"},     // Asia/Singapore
+	"Russia Time Zone 10":             {"SRET", "SRET"},   // Asia/Srednekolymsk
+	"Taipei Standard Time":            {"CST", "CST"},     // Asia/Taipei
+	"West Asia Standard Time":         {"UZT", "UZT"},     // Asia/Tashkent
+	"Georgian Standard Time":          {"GET", "GET"},     // Asia/Tbilisi
+	"Iran Standard Time":              {"IRST", "IRDT"},   // Asia/Tehran
+	"Tokyo Standard Time":             {"JST", "JST"},     // Asia/Tokyo
+	"Tomsk Standard Time":             {"+06", "+07"},     // Asia/Tomsk
+	"Ulaanbaatar Standard Time":       {"ULAT", "ULAST"},  // Asia/Ulaanbaatar
+	"Vladivostok Standard Time":       {"VLAT", "VLAT"},   // Asia/Vladivostok
+	"Yakutsk Standard Time":           {"YAKT", "YAKT"},   // Asia/Yakutsk
+	"Ekaterinburg Standard Time":      {"YEKT", "YEKT"},   // Asia/Yekaterinburg
+	"Caucasus Standard Time":          {"AMT", "AMT"},     // Asia/Yerevan
+	"Azores Standard Time":            {"AZOT", "AZOST"},  // Atlantic/Azores
+	"Cape Verde Standard Time":        {"CVT", "CVT"},     // Atlantic/Cape_Verde
+	"Greenwich Standard Time":         {"GMT", "GMT"},     // Atlantic/Reykjavik
+	"Cen. Australia Standard Time":    {"ACST", "ACDT"},   // Australia/Adelaide
+	"E. Australia Standard Time":      {"AEST", "AEST"},   // Australia/Brisbane
+	"AUS Central Standard Time":       {"ACST", "ACST"},   // Australia/Darwin
+	"Aus Central W. Standard Time":    {"ACWST", "ACWST"}, // Australia/Eucla
+	"Tasmania Standard Time":          {"AEST", "AEDT"},   // Australia/Hobart
+	"Lord Howe Standard Time":         {"LHST", "LHDT"},   // Australia/Lord_Howe
+	"W. Australia Standard Time":      {"AWST", "AWST"},   // Australia/Perth
+	"AUS Eastern Standard Time":       {"AEST", "AEDT"},   // Australia/Sydney
 	"UTC":                            {"GMT", "GMT"},       // Etc/GMT
 	"UTC-11":                         {"GMT+11", "GMT+11"}, // Etc/GMT+11
 	"Dateline Standard Time":         {"GMT+12", "GMT+12"}, // Etc/GMT+12
 	"UTC-02":                         {"GMT+2", "GMT+2"},   // Etc/GMT+2
+	"UTC-08":                         {"GMT+8", "GMT+8"},   // Etc/GMT+8
+	"UTC-09":                         {"GMT+9", "GMT+9"},   // Etc/GMT+9
 	"UTC+12":                         {"GMT-12", "GMT-12"}, // Etc/GMT-12
 	"Astrakhan Standard Time":        {"+03", "+04"},       // Europe/Astrakhan
 	"W. Europe Standard Time":        {"CET", "CEST"},      // Europe/Berlin
@@ -117,10 +131,15 @@ var abbrs = map[string]abbr{
 	"Mauritius Standard Time":        {"MUT", "MUT"},       // Indian/Mauritius
 	"Samoa Standard Time":            {"WSST", "WSDT"},     // Pacific/Apia
 	"New Zealand Standard Time":      {"NZST", "NZDT"},     // Pacific/Auckland
+	"Bougainville Standard Time":     {"BST", "BST"},       // Pacific/Bougainville
+	"Chatham Islands Standard Time":  {"CHAST", "CHADT"},   // Pacific/Chatham
+	"Easter Island Standard Time":    {"EAST", "EASST"},    // Pacific/Easter
 	"Fiji Standard Time":             {"FJT", "FJST"},      // Pacific/Fiji
 	"Central Pacific Standard Time":  {"SBT", "SBT"},       // Pacific/Guadalcanal
 	"Hawaiian Standard Time":         {"HST", "HST"},       // Pacific/Honolulu
 	"Line Islands Standard Time":     {"LINT", "LINT"},     // Pacific/Kiritimati
+	"Marquesas Standard Time":        {"MART", "MART"},     // Pacific/Marquesas
+	"Norfolk Standard Time":          {"NFT", "NFT"},       // Pacific/Norfolk
 	"West Pacific Standard Time":     {"PGT", "PGT"},       // Pacific/Port_Moresby
 	"Tonga Standard Time":            {"TOT", "TOT"},       // Pacific/Tongatapu
 }
diff --git a/libgo/go/time/zoneinfo_android.go b/libgo/go/time/zoneinfo_android.go
new file mode 100644
index 00000000000..695a8adfaa3
--- /dev/null
+++ b/libgo/go/time/zoneinfo_android.go
@@ -0,0 +1,119 @@
+// Copyright 2016 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.
+
+// Parse the "tzdata" packed timezone file used on Android.
+// The format is lifted from ZoneInfoDB.java and ZoneInfo.java in
+// java/libcore/util in the AOSP.
+
+package time
+
+import (
+	"errors"
+	"runtime"
+)
+
+var tzdataPaths = []string{
+	"/system/usr/share/zoneinfo/tzdata",
+	"/data/misc/zoneinfo/current/tzdata",
+	runtime.GOROOT() + "/lib/time/zoneinfo.zip",
+}
+
+var origTzdataPaths = tzdataPaths
+
+func forceZipFileForTesting(zipOnly bool) {
+	tzdataPaths = make([]string, len(origTzdataPaths))
+	copy(tzdataPaths, origTzdataPaths)
+	if zipOnly {
+		for i := 0; i < len(tzdataPaths)-1; i++ {
+			tzdataPaths[i] = "/XXXNOEXIST"
+		}
+	}
+}
+
+func initTestingZone() {
+	z, err := loadLocation("America/Los_Angeles")
+	if err != nil {
+		panic("cannot load America/Los_Angeles for testing: " + err.Error())
+	}
+	z.name = "Local"
+	localLoc = *z
+}
+
+func initLocal() {
+	// TODO(elias.naur): getprop persist.sys.timezone
+	localLoc = *UTC
+}
+
+func loadLocation(name string) (*Location, error) {
+	var firstErr error
+	for _, path := range tzdataPaths {
+		var z *Location
+		var err error
+		if len(path) > 4 && path[len(path)-4:] == ".zip" {
+			z, err = loadZoneZip(path, name)
+		} else {
+			z, err = loadTzdataFile(path, name)
+		}
+		if err == nil {
+			z.name = name
+			return z, nil
+		} else if firstErr == nil && !isNotExist(err) {
+			firstErr = err
+		}
+	}
+	if firstErr != nil {
+		return nil, firstErr
+	}
+	return nil, errors.New("unknown time zone " + name)
+}
+
+func loadTzdataFile(file, name string) (*Location, error) {
+	const (
+		headersize = 12 + 3*4
+		namesize   = 40
+		entrysize  = namesize + 3*4
+	)
+	if len(name) > namesize {
+		return nil, errors.New(name + " is longer than the maximum zone name length (40 bytes)")
+	}
+	fd, err := open(file)
+	if err != nil {
+		return nil, err
+	}
+	defer closefd(fd)
+
+	buf := make([]byte, headersize)
+	if err := preadn(fd, buf, 0); err != nil {
+		return nil, errors.New("corrupt tzdata file " + file)
+	}
+	d := data{buf, false}
+	if magic := d.read(6); string(magic) != "tzdata" {
+		return nil, errors.New("corrupt tzdata file " + file)
+	}
+	d = data{buf[12:], false}
+	indexOff, _ := d.big4()
+	dataOff, _ := d.big4()
+	indexSize := dataOff - indexOff
+	entrycount := indexSize / entrysize
+	buf = make([]byte, indexSize)
+	if err := preadn(fd, buf, int(indexOff)); err != nil {
+		return nil, errors.New("corrupt tzdata file " + file)
+	}
+	for i := 0; i < int(entrycount); i++ {
+		entry := buf[i*entrysize : (i+1)*entrysize]
+		// len(name) <= namesize is checked at function entry
+		if string(entry[:len(name)]) != name {
+			continue
+		}
+		d := data{entry[namesize:], false}
+		off, _ := d.big4()
+		size, _ := d.big4()
+		buf := make([]byte, size)
+		if err := preadn(fd, buf, int(off+dataOff)); err != nil {
+			return nil, errors.New("corrupt tzdata file " + file)
+		}
+		return loadZoneData(buf)
+	}
+	return nil, errors.New("cannot find " + name + " in tzdata file " + file)
+}
diff --git a/libgo/go/time/zoneinfo_android_test.go b/libgo/go/time/zoneinfo_android_test.go
new file mode 100644
index 00000000000..ba065d10a65
--- /dev/null
+++ b/libgo/go/time/zoneinfo_android_test.go
@@ -0,0 +1,18 @@
+// Copyright 2016 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 time_test
+
+import (
+	"testing"
+	. "time"
+)
+
+func TestAndroidTzdata(t *testing.T) {
+	ForceAndroidTzdataForTest(true)
+	defer ForceAndroidTzdataForTest(false)
+	if _, err := LoadLocation("America/Los_Angeles"); err != nil {
+		t.Error(err)
+	}
+}
diff --git a/libgo/go/time/zoneinfo_unix.go b/libgo/go/time/zoneinfo_unix.go
index 6c7aafff77b..772748818a9 100644
--- a/libgo/go/time/zoneinfo_unix.go
+++ b/libgo/go/time/zoneinfo_unix.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin,386 darwin,amd64 dragonfly freebsd linux nacl netbsd openbsd solaris
+// +build darwin,386 darwin,amd64 dragonfly freebsd linux,!android nacl netbsd openbsd solaris
 
 // Parse "zoneinfo" time zone file.
 // This is a fairly standard file format used on OS X, Linux, BSD, Sun, and others.
diff --git a/libgo/go/time/zoneinfo_windows.go b/libgo/go/time/zoneinfo_windows.go
index a6546f54b86..a6e227b5b0d 100644
--- a/libgo/go/time/zoneinfo_windows.go
+++ b/libgo/go/time/zoneinfo_windows.go
@@ -11,8 +11,6 @@ import (
 	"syscall"
 )
 
-//go:generate go run genzabbrs.go -output zoneinfo_abbrs_windows.go
-
 // TODO(rsc): Fall back to copy of zoneinfo files.
 
 // BUG(brainman,rsc): On Windows, the operating system does not provide complete