1 files changed, 118 insertions, 16 deletions

diff --git a/libgo/go/time/zoneinfo_windows.go b/libgo/go/time/zoneinfo_windows.go
index a8d3dcbfeb1..1e18ad295df 100644
--- a/libgo/go/time/zoneinfo_windows.go
+++ b/libgo/go/time/zoneinfo_windows.go
@@ -8,6 +8,7 @@ import (
 	"errors"
 	"runtime"
 	"syscall"
+	"unsafe"
 )
 
 // TODO(rsc): Fall back to copy of zoneinfo files.
@@ -16,21 +17,83 @@ import (
 // time zone information.
 // The implementation assumes that this year's rules for daylight savings
 // time apply to all previous and future years as well.
-// Also, time zone abbreviations are unavailable.  The implementation constructs
-// them using the capital letters from a longer time zone description.
-
-// abbrev returns the abbreviation to use for the given zone name.
-func abbrev(name []uint16) string {
-	// name is 'Pacific Standard Time' but we want 'PST'.
-	// Extract just capital letters.  It's not perfect but the
-	// information we need is not available from the kernel.
-	// Because time zone abbreviations are not unique,
-	// Windows refuses to expose them.
-	//
-	// http://social.msdn.microsoft.com/Forums/eu/vclanguage/thread/a87e1d25-fb71-4fe0-ae9c-a9578c9753eb
-	// http://stackoverflow.com/questions/4195948/windows-time-zone-abbreviations-in-asp-net
+
+// getKeyValue retrieves the string value kname associated with the open registry key kh.
+func getKeyValue(kh syscall.Handle, kname string) (string, error) {
+	var buf [50]uint16 // buf needs to be large enough to fit zone descriptions
+	var typ uint32
+	n := uint32(len(buf) * 2) // RegQueryValueEx's signature expects array of bytes, not uint16
+	p, _ := syscall.UTF16PtrFromString(kname)
+	if err := syscall.RegQueryValueEx(kh, p, nil, &typ, (*byte)(unsafe.Pointer(&buf[0])), &n); err != nil {
+		return "", err
+	}
+	if typ != syscall.REG_SZ { // null terminated strings only
+		return "", errors.New("Key is not string")
+	}
+	return syscall.UTF16ToString(buf[:]), nil
+}
+
+// matchZoneKey checks if stdname and dstname match the corresponding "Std"
+// and "Dlt" key values in the kname key stored under the open registry key zones.
+func matchZoneKey(zones syscall.Handle, kname string, stdname, dstname string) (matched bool, err2 error) {
+	var h syscall.Handle
+	p, _ := syscall.UTF16PtrFromString(kname)
+	if err := syscall.RegOpenKeyEx(zones, p, 0, syscall.KEY_READ, &h); err != nil {
+		return false, err
+	}
+	defer syscall.RegCloseKey(h)
+
+	s, err := getKeyValue(h, "Std")
+	if err != nil {
+		return false, err
+	}
+	if s != stdname {
+		return false, nil
+	}
+	s, err = getKeyValue(h, "Dlt")
+	if err != nil {
+		return false, err
+	}
+	if s != dstname {
+		return false, nil
+	}
+	return true, nil
+}
+
+// toEnglishName searches the registry for an English name of a time zone
+// whose zone names are stdname and dstname and returns the English name.
+func toEnglishName(stdname, dstname string) (string, error) {
+	var zones syscall.Handle
+	p, _ := syscall.UTF16PtrFromString(`SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones`)
+	if err := syscall.RegOpenKeyEx(syscall.HKEY_LOCAL_MACHINE, p, 0, syscall.KEY_READ, &zones); err != nil {
+		return "", err
+	}
+	defer syscall.RegCloseKey(zones)
+
+	var count uint32
+	if err := syscall.RegQueryInfoKey(zones, nil, nil, nil, &count, nil, nil, nil, nil, nil, nil, nil); err != nil {
+		return "", err
+	}
+
+	var buf [50]uint16 // buf needs to be large enough to fit zone descriptions
+	for i := uint32(0); i < count; i++ {
+		n := uint32(len(buf))
+		if syscall.RegEnumKeyEx(zones, i, &buf[0], &n, nil, nil, nil, nil) != nil {
+			continue
+		}
+		kname := syscall.UTF16ToString(buf[:])
+		matched, err := matchZoneKey(zones, kname, stdname, dstname)
+		if err == nil && matched {
+			return kname, nil
+		}
+	}
+	return "", errors.New(`English name for time zone "` + stdname + `" not found in registry`)
+}
+
+// extractCAPS exracts capital letters from description desc.
+func extractCAPS(desc string) string {
 	var short []rune
-	for _, c := range name {
+	for _, c := range desc {
 		if 'A' <= c && c <= 'Z' {
 			short = append(short, rune(c))
 		}
@@ -38,6 +101,26 @@ func abbrev(name []uint16) string {
 	return string(short)
 }
 
+// abbrev returns the abbreviations to use for the given zone z.
+func abbrev(z *syscall.Timezoneinformation) (std, dst string) {
+	stdName := syscall.UTF16ToString(z.StandardName[:])
+	a, ok := abbrs[stdName]
+	if !ok {
+		dstName := syscall.UTF16ToString(z.DaylightName[:])
+		// Perhaps stdName is not English. Try to convert it.
+		englishName, err := toEnglishName(stdName, dstName)
+		if err == nil {
+			a, ok = abbrs[englishName]
+			if ok {
+				return a.std, a.dst
+			}
+		}
+		// fallback to using capital letters
+		return extractCAPS(stdName), extractCAPS(dstName)
+	}
+	return a.std, a.dst
+}
+
 // pseudoUnix returns the pseudo-Unix time (seconds since Jan 1 1970 *LOCAL TIME*)
 // denoted by the system date+time d in the given year.
 // It is up to the caller to convert this local time into a UTC-based time.
@@ -75,8 +158,10 @@ func initLocalFromTZI(i *syscall.Timezoneinformation) {
 	}
 	l.zone = make([]zone, nzone)
 
+	stdname, dstname := abbrev(i)
+
 	std := &l.zone[0]
-	std.name = abbrev(i.StandardName[0:])
+	std.name = stdname
 	if nzone == 1 {
 		// No daylight savings.
 		std.offset = -int(i.Bias) * 60
@@ -95,7 +180,7 @@ func initLocalFromTZI(i *syscall.Timezoneinformation) {
 	std.offset = -int(i.Bias+i.StandardBias) * 60
 
 	dst := &l.zone[1]
-	dst.name = abbrev(i.DaylightName[0:])
+	dst.name = dstname
 	dst.offset = -int(i.Bias+i.DaylightBias) * 60
 	dst.isDST = true
 
@@ -142,10 +227,27 @@ var usPacific = syscall.Timezoneinformation{
 	DaylightBias: -60,
 }
 
+var aus = syscall.Timezoneinformation{
+	Bias: -10 * 60,
+	StandardName: [32]uint16{
+		'A', 'U', 'S', ' ', 'E', 'a', 's', 't', 'e', 'r', 'n', ' ', 'S', 't', 'a', 'n', 'd', 'a', 'r', 'd', ' ', 'T', 'i', 'm', 'e',
+	},
+	StandardDate: syscall.Systemtime{Month: 4, Day: 1, Hour: 3},
+	DaylightName: [32]uint16{
+		'A', 'U', 'S', ' ', 'E', 'a', 's', 't', 'e', 'r', 'n', ' ', 'D', 'a', 'y', 'l', 'i', 'g', 'h', 't', ' ', 'T', 'i', 'm', 'e',
+	},
+	DaylightDate: syscall.Systemtime{Month: 10, Day: 1, Hour: 2},
+	DaylightBias: -60,
+}
+
 func initTestingZone() {
 	initLocalFromTZI(&usPacific)
 }
 
+func initAusTestingZone() {
+	initLocalFromTZI(&aus)
+}
+
 func initLocal() {
 	var i syscall.Timezoneinformation
 	if _, err := syscall.GetTimeZoneInformation(&i); err != nil {