fixes: panic on empty trie iteration #6

Author: timtadh

trie/tst.go

@@ -212,6 +212,9 @@ func (self *TST) Iterate() KVIterator {
 	kv_iterator = func() (key Hashable, value interface{}, next KVIterator) {
 		var tn TreeNode
 		for {
+			if tni == nil {
+				return nil, nil, nil
+			}
 			tn, tni = tni()
 			if tni == nil {
 				return nil, nil, nil

trie/tst_test.go

@@ -70,6 +70,14 @@ func (self ByteSlices) Swap(i, j int) {
 	self[i], self[j] = self[j], self[i]
 }
 
+func TestEmptyIter(t *testing.T) {
+	table := New()
+	for _, _, next := table.Iterate()(); next != nil; _, _, next = next() {
+		t.Errorf("should have been empty")
+	}
+
+}
+
 func TestIteratorPrefixFindDotty(t *testing.T) {
 	items := ByteSlices{
 		types.ByteSlice("0:java.io.File;"),