Add wrapping around to key_to_nodes

lib/ring.ex

@@ -246,27 +246,32 @@ defmodule HashRing do
 
     case :gb_trees.iterator_from(hash, r) |> :gb_trees.next() do
       {_key, node, iter} ->
-        find_nodes_from_iter(iter, count - 1, [node])
+        find_nodes_from_iter(r, iter, count - 1, [node], _restarted? = false)
 
       _ ->
         {_key, node} = :gb_trees.smallest(r)
         [node]
     end
   end
 
-  defp find_nodes_from_iter(_iter, 0, results), do: Enum.reverse(results)
+  defp find_nodes_from_iter(_ring, _iter, 0, results, _restared?), do: Enum.reverse(results)
 
-  defp find_nodes_from_iter(iter, count, results) do
+  defp find_nodes_from_iter(ring, iter, count, results, restarted?) do
     case :gb_trees.next(iter) do
       {_key, node, iter} ->
         if node in results do
-          find_nodes_from_iter(iter, count, results)
+          find_nodes_from_iter(ring, iter, count, results, restarted?)
         else
-          find_nodes_from_iter(iter, count - 1, [node | results])
+          find_nodes_from_iter(ring, iter, count - 1, [node | results], restarted?)
         end
 
-      _ ->
-        results
+      :none ->
+        if restarted? do
+          Enum.reverse(results)
+        else
+          restart_iter = :gb_trees.iterator(ring)
+          find_nodes_from_iter(ring, restart_iter, count, results, _restarted? = true)
+        end
     end
   end
 end

test/hashring_test.exs

@@ -19,6 +19,16 @@ defmodule HashRingTest do
     assert length(nodes) == 2
   end
 
+  # https://github.com/bitwalker/libring/issues/39
+  test "key_to_nodes/3 test 14" do
+    ring =
+      HashRing.new()
+      |> HashRing.add_node(:a@localhost)
+      |> HashRing.add_node(:b@localhost)
+
+    assert HashRing.key_to_nodes(ring, 14, 2) == [:a@localhost, :b@localhost]
+  end
+
   property "adding one node leaves us with a tree with one node" do
     check all(name <- string(:printable, min_length: 1)) do
       %HashRing{nodes: nodes} = HashRing.new(name)