impl/memory: Fix time serialization encoding.

service/datastore/serialize/serialize.go

Index: service/datastore/serialize/serialize.go
diff --git a/service/datastore/serialize/serialize.go b/service/datastore/serialize/serialize.go
index 736010820f222499212728ca30154029a905cc4f..a6210c6b49f6ed381b397f6fbdc6408316b35bf2 100644
--- a/service/datastore/serialize/serialize.go
+++ b/service/datastore/serialize/serialize.go
@@ -189,6 +189,13 @@ func ReadGeoPoint(buf Buffer) (gp ds.GeoPoint, err error) {
 	return
 }
 
+// timeToInt converts a time value to an integer value. See WriteTime for more
+// details.
+func timeToInt(t time.Time) int64 {
+	t = t.Round(time.Microsecond)
+	return t.Unix()*1e6 + int64(t.Nanosecond()/1e3)
+}
+
 // WriteTime writes a time.Time in a byte-sortable way.
 //
 // This method truncates the time to microseconds and drops the timezone,
@@ -198,7 +205,7 @@ func WriteTime(buf Buffer, t time.Time) error {
 	if name != "UTC" || off != 0 {
 		panic(fmt.Errorf("helper: UTC OR DEATH: %s", t))
 	}
-	_, err := cmpbin.WriteInt(buf, t.Unix()*1e6+int64(t.Nanosecond()/1e3))
+	_, err := cmpbin.WriteInt(buf, timeToInt(t))
 	return err
 }
 
@@ -220,7 +227,14 @@ func ReadTime(buf Buffer) (time.Time, error) {
 // Key as its Value.
 func WriteProperty(buf Buffer, context KeyContext, p ds.Property) (err error) {
 	defer recoverTo(&err)
-	typb := byte(p.Type())
+
+	effectiveType := p.Type()
+	switch effectiveType {
+	case ds.PTTime:

[dnj, 2015/12/29 16:48:09]

I made this a switch statement in case there were other instances of data types
that made serialization-level type changes. If it's just PTTime, I could
simplify this, although probably with little gain.

+		effectiveType = ds.PTInt
+	}
+	typb := byte(effectiveType)

[iannucci, 2015/12/29 18:29:20]

This change is not good; it will call property maps to fail to round-trip to the
datastore.

+
 	if p.IndexSetting() != ds.NoIndex {
 		typb |= 0x80
 	}