Deal with wrapping handles in portableHandleMap.

fuse/handle.go

@@ -48,11 +48,23 @@ func (me *portableHandleMap) Register(obj *Handled, asInt interface{}) uint64 {
 	}
 	me.Lock()
 	defer me.Unlock()
+	for {
 		h := uint64(me.nextFree)
 		me.nextFree++
+		if h < 2 {
+			continue
+		}
+		old := me.handles[h]
+		if old != nil {
+			continue
+		}
+
 		me.handles[h] = obj
 		obj.check = 0xbaabbaab
 		return h
+	}
+
+	return 0
 }
 
 func (me *portableHandleMap) Count() int {
@@ -154,7 +166,6 @@ func (me *int64HandleMap) verify() {
 func NewHandleMap(portable bool) (hm HandleMap) {
 	if portable {
 		return &portableHandleMap{
-			nextFree: 2,
 			handles: make(map[uint64]*Handled),
 		}
 	}