1 files changed, 55 insertions, 10 deletions
diff --git a/trie/iterator_test.go b/trie/iterator_test.go
index 04d51aaf5..f161fd99d 100644
--- a/trie/iterator_test.go
+++ b/trie/iterator_test.go
@@ -17,6 +17,8 @@
 package trie
 
 import (
+	"bytes"
+	"fmt"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -42,7 +44,7 @@ func TestIterator(t *testing.T) {
 	trie.Commit()
 
 	found := make(map[string]string)
-	it := NewIterator(trie.NodeIterator())
+	it := NewIterator(trie.NodeIterator(nil))
 	for it.Next() {
 		found[string(it.Key)] = string(it.Value)
 	}
@@ -72,7 +74,7 @@ func TestIteratorLargeData(t *testing.T) {
 		vals[string(value2.k)] = value2
 	}
 
-	it := NewIterator(trie.NodeIterator())
+	it := NewIterator(trie.NodeIterator(nil))
 	for it.Next() {
 		vals[string(it.Key)].t = true
 	}
@@ -99,7 +101,7 @@ func TestNodeIteratorCoverage(t *testing.T) {
 
 	// Gather all the node hashes found by the iterator
 	hashes := make(map[common.Hash]struct{})
-	for it := trie.NodeIterator(); it.Next(true); {
+	for it := trie.NodeIterator(nil); it.Next(true); {
 		if it.Hash() != (common.Hash{}) {
 			hashes[it.Hash()] = struct{}{}
 		}
@@ -117,18 +119,20 @@ func TestNodeIteratorCoverage(t *testing.T) {
 	}
 }
 
-var testdata1 = []struct{ k, v string }{
-	{"bar", "b"},
+type kvs struct{ k, v string }
+
+var testdata1 = []kvs{
 	{"barb", "ba"},
-	{"bars", "bb"},
 	{"bard", "bc"},
+	{"bars", "bb"},
+	{"bar", "b"},
 	{"fab", "z"},
-	{"foo", "a"},
 	{"food", "ab"},
 	{"foos", "aa"},
+	{"foo", "a"},
 }
 
-var testdata2 = []struct{ k, v string }{
+var testdata2 = []kvs{
 	{"aardvark", "c"},
 	{"bar", "b"},
 	{"barb", "bd"},
@@ -140,6 +144,47 @@ var testdata2 = []struct{ k, v string }{
 	{"jars", "d"},
 }
 
+func TestIteratorSeek(t *testing.T) {
+	trie := newEmpty()
+	for _, val := range testdata1 {
+		trie.Update([]byte(val.k), []byte(val.v))
+	}
+
+	// Seek to the middle.
+	it := NewIterator(trie.NodeIterator([]byte("fab")))
+	if err := checkIteratorOrder(testdata1[4:], it); err != nil {
+		t.Fatal(err)
+	}
+
+	// Seek to a non-existent key.
+	it = NewIterator(trie.NodeIterator([]byte("barc")))
+	if err := checkIteratorOrder(testdata1[1:], it); err != nil {
+		t.Fatal(err)
+	}
+
+	// Seek beyond the end.
+	it = NewIterator(trie.NodeIterator([]byte("z")))
+	if err := checkIteratorOrder(nil, it); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func checkIteratorOrder(want []kvs, it *Iterator) error {
+	for it.Next() {
+		if len(want) == 0 {
+			return fmt.Errorf("didn't expect any more values, got key %q", it.Key)
+		}
+		if !bytes.Equal(it.Key, []byte(want[0].k)) {
+			return fmt.Errorf("wrong key: got %q, want %q", it.Key, want[0].k)
+		}
+		want = want[1:]
+	}
+	if len(want) > 0 {
+		return fmt.Errorf("iterator ended early, want key %q", want[0])
+	}
+	return nil
+}
+
 func TestDifferenceIterator(t *testing.T) {
 	triea := newEmpty()
 	for _, val := range testdata1 {
@@ -154,7 +199,7 @@ func TestDifferenceIterator(t *testing.T) {
 	trieb.Commit()
 
 	found := make(map[string]string)
-	di, _ := NewDifferenceIterator(triea.NodeIterator(), trieb.NodeIterator())
+	di, _ := NewDifferenceIterator(triea.NodeIterator(nil), trieb.NodeIterator(nil))
 	it := NewIterator(di)
 	for it.Next() {
 		found[string(it.Key)] = string(it.Value)
@@ -189,7 +234,7 @@ func TestUnionIterator(t *testing.T) {
 	}
 	trieb.Commit()
 
-	di, _ := NewUnionIterator([]NodeIterator{triea.NodeIterator(), trieb.NodeIterator()})
+	di, _ := NewUnionIterator([]NodeIterator{triea.NodeIterator(nil), trieb.NodeIterator(nil)})
 	it := NewIterator(di)
 
 	all := []struct{ k, v string }{