From b2ce50721b56187223a450565ab975f6a61ab658 Mon Sep 17 00:00:00 2001
From: Daniel Spofford <daniel.spofford@verypossible.com>
Date: Wed, 10 Apr 2019 18:31:10 -0500
Subject: [PATCH] Fix ArrayedData WRT an empty binary

---
 lib/harald/hci/arrayed_data.ex        |  4 ++++
 test/harald/hci/arrayed_data_test.exs | 12 ++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 test/harald/hci/arrayed_data_test.exs

diff --git a/lib/harald/hci/arrayed_data.ex b/lib/harald/hci/arrayed_data.ex
index c8038df..a668ed7 100644
--- a/lib/harald/hci/arrayed_data.ex
+++ b/lib/harald/hci/arrayed_data.ex
@@ -60,6 +60,10 @@ defmodule Harald.HCI.ArrayedData do
   @doc """
   Deserializes the binary representation of a list of structs according to `schema`.
   """
+  def deserialize(schema, length, struct_module, bin)
+
+  def deserialize(_, length, _, <<>>) when length > 0, do: {:error, :incomplete}
+
   def deserialize(schema, length, struct_module, bin) do
     schema
     |> deserialize(bin, %{
diff --git a/test/harald/hci/arrayed_data_test.exs b/test/harald/hci/arrayed_data_test.exs
new file mode 100644
index 0000000..3210aae
--- /dev/null
+++ b/test/harald/hci/arrayed_data_test.exs
@@ -0,0 +1,12 @@
+defmodule Harald.HCI.ArrayedDataTest do
+  use ExUnit.Case, async: true
+  alias Harald.HCI.{ArrayedData, Event.LEMeta.AdvertisingReport.Device}
+
+  doctest ArrayedData, import: true
+
+  describe "deserialize/4" do
+    test "an empty binary results in an error" do
+      assert {:error, :incomplete} == ArrayedData.deserialize([], 1, Device, <<>>)
+    end
+  end
+end