From 88c51f4933beb69f17002810afbe3bfe090f0cf6 Mon Sep 17 00:00:00 2001
From: David Sparer <sparerd@gmail.com>
Date: Sun, 9 Apr 2017 16:57:56 -0600
Subject: [PATCH] added some safety checks to the data table serialier

---
 .../Serializers/DataTableSerializerTests.cs   | 22 ++++++++++-----
 .../Config/Serializers/DataTableSerializer.cs | 27 ++++++++++++++-----
 2 files changed, 36 insertions(+), 13 deletions(-)

diff --git a/mRemoteNGTests/Config/Serializers/DataTableSerializerTests.cs b/mRemoteNGTests/Config/Serializers/DataTableSerializerTests.cs
index a8a5f1f9..fa114a95 100644
--- a/mRemoteNGTests/Config/Serializers/DataTableSerializerTests.cs
+++ b/mRemoteNGTests/Config/Serializers/DataTableSerializerTests.cs
@@ -20,13 +20,6 @@ namespace mRemoteNGTests.Config.Serializers
             _dataTableSerializer = new DataTableSerializer(_saveFilter);
         }
 
-        [TearDown]
-        public void Teardown()
-        {
-            _saveFilter = null;
-            _dataTableSerializer = null;
-        }
-
         [Test]
         public void AllItemsSerialized()
         {
@@ -35,6 +28,14 @@ namespace mRemoteNGTests.Config.Serializers
             Assert.That(dataTable.Rows.Count, Is.EqualTo(3));
         }
 
+        [Test]
+        public void ReturnsEmptyDataTableWhenGivenEmptyConnectionTreeModel()
+        {
+            var model = new ConnectionTreeModel();
+            var dataTable = _dataTableSerializer.Serialize(model);
+            Assert.That(dataTable.Rows.Count, Is.EqualTo(0));
+        }
+
         [Test]
         public void UsernameSerializedWhenSaveSecurityAllowsIt()
         {
@@ -109,6 +110,13 @@ namespace mRemoteNGTests.Config.Serializers
             Assert.That(dataTable.Rows[0]["InheritUsername"], Is.False);
         }
 
+        [Test]
+        public void CanSerializeEmptyConnectionInfo()
+        {
+            var dataTable = _dataTableSerializer.Serialize(new ConnectionInfo());
+            Assert.That(dataTable.Rows.Count, Is.EqualTo(1));
+        }
+
 
         private ConnectionTreeModel CreateConnectionTreeModel()
         {
diff --git a/mRemoteV1/Config/Serializers/DataTableSerializer.cs b/mRemoteV1/Config/Serializers/DataTableSerializer.cs
index 22a1ceb8..183727a3 100644
--- a/mRemoteV1/Config/Serializers/DataTableSerializer.cs
+++ b/mRemoteV1/Config/Serializers/DataTableSerializer.cs
@@ -25,20 +25,35 @@ namespace mRemoteNG.Config.Serializers
 
         public DataTable Serialize(ConnectionTreeModel connectionTreeModel)
         {
-            var rootNode = (RootNodeInfo)connectionTreeModel.RootNodes.First(node => node is RootNodeInfo);
-            return Serialize(rootNode);
+            try
+            {
+                _dataTable = BuildTable();
+                _currentNodeIndex = 0;
+                var rootNode = connectionTreeModel.RootNodes.First(node => node is RootNodeInfo);
+                return Serialize(rootNode);
+            }
+            catch
+            {
+                return _dataTable;
+            }
         }
 
         public DataTable Serialize(ConnectionInfo serializationTarget)
         {
-            _dataTable = new DataTable(TableName);
-            CreateSchema();
-            SetPrimaryKey();
+            _dataTable = BuildTable();
             _currentNodeIndex = 0;
             SerializeNodesRecursive(serializationTarget);
             return _dataTable;
         }
 
+        private DataTable BuildTable()
+        {
+            var dataTable = new DataTable(TableName);
+            CreateSchema();
+            SetPrimaryKey();
+            return dataTable;
+        }
+
         private void CreateSchema()
         {
             // Note: these columns must be defined in the same order that they exist in the DB
@@ -186,7 +201,7 @@ namespace mRemoteNG.Config.Serializers
             dataRow["Name"] = connectionInfo.Name;
             dataRow["Type"] = connectionInfo.GetTreeNodeType().ToString();
             dataRow["ConstantID"] = connectionInfo.ConstantID;
-            dataRow["ParentID"] = connectionInfo.Parent.ConstantID;
+            dataRow["ParentID"] = connectionInfo.Parent?.ConstantID;
             dataRow["PositionID"] = _currentNodeIndex;
             dataRow["LastChange"] = (SqlDateTime)DateTime.Now;
             var info = connectionInfo as ContainerInfo;