fix(lib/trie): handleDeletion generation propagation

lib/trie/trie.go

@@ -764,7 +764,7 @@ func handleDeletion(p *node.Branch, key []byte) Node {
 
 	// if branch has no children, just a value, turn it into a leaf
 	if bitmap == 0 && p.Value != nil {
-		n = node.NewLeaf(key[:length], p.Value, true, 0)
+		n = node.NewLeaf(key[:length], p.Value, true, p.Generation)
 	} else if p.NumChildren() == 1 && p.Value == nil {
 		// there is only 1 child and no value, combine the child branch with this branch
 		// find index of child
@@ -779,7 +779,14 @@ func handleDeletion(p *node.Branch, key []byte) Node {
 		child := p.Children[i]
 		switch c := child.(type) {
 		case *node.Leaf:
-			n = &node.Leaf{Key: append(append(p.Key, []byte{byte(i)}...), c.Key...), Value: c.Value}
+			key = append(append(p.Key, []byte{byte(i)}...), c.Key...)
+			const dirty = true
+			n = node.NewLeaf(
+				key,
+				c.Value,
+				dirty,
+				p.Generation,
+			)
 		case *node.Branch:
 			br := new(node.Branch)
 			br.Key = append(p.Key, append([]byte{byte(i)}, c.Key...)...)
@@ -792,6 +799,7 @@ func handleDeletion(p *node.Branch, key []byte) Node {
 			}
 
 			br.Value = c.Value
+			br.Generation = p.Generation
 			n = br
 		default:
 			// do nothing

lib/trie/trie_endtoend_test.go

@@ -938,8 +938,9 @@ func TestClearPrefix_Small(t *testing.T) {
 	ssTrie.ClearPrefix([]byte("noo"))
 
 	expectedRoot := &node.Leaf{
-		Key:   codec.KeyLEToNibbles([]byte("other")),
-		Value: []byte("other"),
+		Key:        codec.KeyLEToNibbles([]byte("other")),
+		Value:      []byte("other"),
+		Generation: 1,
 	}
 	expectedRoot.SetDirty(true)