time: fix zone during windows test

Factor out sleep interrupt.

Fixes issue 1109.

R=alex.brainman, go.peter.90, mattn.jp
CC=golang-dev
http://codereview.appspot.com/4968041

1 files changed, 43 insertions, 1 deletions

diff --git a/src/pkg/time/zoneinfo_windows.go b/src/pkg/time/zoneinfo_windows.go
index fabc00601..ab3e7df59 100644
--- a/src/pkg/time/zoneinfo_windows.go
+++ b/src/pkg/time/zoneinfo_windows.go
@@ -27,9 +27,30 @@ type zone struct {
 	prev                  *zone
 }
 
+// BUG(rsc): On Windows, time zone abbreviations are unavailable.
+// This package constructs them using the capital letters from a longer
+// time zone description.
+
 // Populate zone struct with Windows supplied information. Returns true, if data is valid.
 func (z *zone) populate(bias, biasdelta int32, d *syscall.Systemtime, name []uint16) (dateisgood bool) {
-	z.name = syscall.UTF16ToString(name)
+	// 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
+	short := make([]uint16, len(name))
+	w := 0
+	for _, c := range name {
+		if 'A' <= c && c <= 'Z' {
+			short[w] = c
+			w++
+		}
+	}
+	z.name = syscall.UTF16ToString(short[:w])
+
 	z.offset = int(bias)
 	z.year = int64(d.Year)
 	z.month = int(d.Month)
@@ -129,6 +150,10 @@ func setupZone() {
 		initError = os.NewSyscallError("GetTimeZoneInformation", e)
 		return
 	}
+	setupZoneFromTZI(&i)
+}
+
+func setupZoneFromTZI(i *syscall.Timezoneinformation) {
 	if !tz.std.populate(i.Bias, i.StandardBias, &i.StandardDate, i.StandardName[0:]) {
 		tz.disabled = true
 		tz.offsetIfDisabled = tz.std.offset
@@ -144,6 +169,23 @@ func setupZone() {
 	tz.januaryIsStd = tz.dst.cutoffSeconds(t.Year) < tz.std.cutoffSeconds(t.Year)
 }
 
+var usPacific = syscall.Timezoneinformation{
+	Bias: 8 * 60,
+	StandardName: [32]uint16{
+		'P', 'a', 'c', 'i', 'f', 'i', 'c', ' ', 'S', 't', 'a', 'n', 'd', 'a', 'r', 'd', ' ', 'T', 'i', 'm', 'e',
+	},
+	StandardDate: syscall.Systemtime{Month: 11, Day: 1, Hour: 2},
+	DaylightName: [32]uint16{
+		'P', 'a', 'c', 'i', 'f', 'i', 'c', ' ', 'D', 'a', 'y', 'l', 'i', 'g', 'h', 't', ' ', 'T', 'i', 'm', 'e',
+	},
+	DaylightDate: syscall.Systemtime{Month: 3, Day: 2, Hour: 2},
+	DaylightBias: -60,
+}
+
+func setupTestingZone() {
+	setupZoneFromTZI(&usPacific)
+}
+
 // Look up the correct time zone (daylight savings or not) for the given unix time, in the current location.
 func lookupTimezone(sec int64) (zone string, offset int) {
 	onceSetupZone.Do(setupZone)