From 59a0aa3667345bdc1a7015c548c9350e3497bc30 Mon Sep 17 00:00:00 2001
From: James F McMahon <JamesMcMahon@users.noreply.github.com>
Date: Mon, 23 May 2016 15:21:35 -0500
Subject: [PATCH] Fix null achievement array

Need to return if not authenticated, otherwise `mClient.LoadAchievements` will fail with a null achievement array.

Also added a null guard around the callback invocation.

Full error:

```
NullReferenceException: Object reference not set to an instance of an object
GooglePlayGames.PlayGamesPlatform+<LoadAchievements>c__AnonStorey9.<>m__5 (GooglePlayGames.BasicApi.Achievement[] ach)
GooglePlayGames.BasicApi.DummyClient.LoadAchievements (System.Action`1 callback)
GooglePlayGames.PlayGamesPlatform.LoadAchievements (System.Action`1 callback)
UnityEngine.Social.LoadAchievements (System.Action`1 callback)
```
---
 .../GooglePlayGames/ISocialPlatform/PlayGamesPlatform.cs    | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/source/PluginDev/Assets/GooglePlayGames/ISocialPlatform/PlayGamesPlatform.cs b/source/PluginDev/Assets/GooglePlayGames/ISocialPlatform/PlayGamesPlatform.cs
index 6eaca7813..366623df6 100644
--- a/source/PluginDev/Assets/GooglePlayGames/ISocialPlatform/PlayGamesPlatform.cs
+++ b/source/PluginDev/Assets/GooglePlayGames/ISocialPlatform/PlayGamesPlatform.cs
@@ -829,7 +829,11 @@ public void LoadAchievementDescriptions(Action<IAchievementDescription[]> callba
             {
                 GooglePlayGames.OurUtils.Logger.e(
                     "LoadAchievementDescriptions can only be called after authentication.");
-                callback.Invoke(null);
+                if (callback != null)
+                {
+                    callback.Invoke(null);
+                }
+                return;
             }
 
             mClient.LoadAchievements(ach =>