Created a test-suite for the multithreaded problems

Source/Svg.csproj

@@ -353,6 +353,7 @@
   </ItemGroup>
   <ItemGroup>
     <None Include="Basic Shapes\DOM.cd" />
+    <None Include="Svg.nuspec" />
     <None Include="svgkey.snk" />
   </ItemGroup>
   <Import Project="$(MSBuildBinPath)\Microsoft.CSharp.targets" />

Source/Svg.nuspec

+<?xml version="1.0"?>
+<package >
+  <metadata>
+    <id>$id$</id>
+    <version>$version$</version>
+    <title>$title$</title>
+    <authors>$author$</authors>
+    <owners>$author$</owners>
+    <description>TaxModel/PAW altered implementation of the Svg library</description>
+  </metadata>
+</package>
\ No newline at end of file

Tests/Svg.UnitTests/CssQueryTest.cs

@@ -5,8 +5,6 @@ using ExCSS;
 
 namespace Svg.UnitTests
 {
-    
-    
 	/// <summary>
 	///This is a test class for CssQueryTest and is intended
 	///to contain all CssQueryTest Unit Tests

Tests/Svg.UnitTests/MultiThreadingTest.cs

+using System;
+using System.Diagnostics;
+using System.Drawing;
+using System.Drawing.Imaging;
+using System.IO;
+using System.Threading.Tasks;
+using System.Xml;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Svg.UnitTests
+{
+
+	[TestClass()]
+	public class MultiThreadingTest
+	{
+
+		private const string TestFile = @"d:\temp\test.svg";
+		private const int ExpectedSize = 600000;
+		private XmlDocument GetXMLDoc()
+		{
+			var xmlDoc = new XmlDocument();
+			if(!System.IO.File.Exists(TestFile)) { Assert.Inconclusive("Test file missing"); }
+			xmlDoc.LoadXml(System.IO.File.ReadAllText(TestFile));
+			return xmlDoc;
+		}
+
+		[TestMethod]
+		public void TestSingleThread()
+		{
+			LoadFile();
+		}
+
+		[TestMethod]
+		public void TestMultiThread()
+		{
+			bool valid = true;
+			Parallel.For(0, 10, (x) =>
+			{
+				try
+				{
+					LoadFile();
+				}
+				catch (Exception e)
+				{
+					Trace.WriteLine("Run error in parallel: " + e.Message);
+					valid = false;
+				}
+			});
+			Assert.IsTrue(valid, "One or more of the runs was invalid");
+			Trace.WriteLine("Done");
+		}
+		private void LoadFile()
+		{
+			var xml = GetXMLDoc();
+			Trace.WriteLine("Reading and drawing file");
+			SvgDocument d = SvgDocument.Open(xml);
+			var b = d.Draw();
+			Trace.WriteLine("Done reading file");
+			using (var ms = new MemoryStream())
+			{
+				b.Save(ms, ImageFormat.Png);
+				ms.Flush();
+				Assert.IsTrue(ms.Length >= ExpectedSize, "File does not match expected minimum size");
+			}
+		}
+	}
+}
\ No newline at end of file

Tests/Svg.UnitTests/Svg.UnitTests.csproj

@@ -49,6 +49,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="CssQueryTest.cs" />
+    <Compile Include="MultiThreadingTest.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
   </ItemGroup>
   <ItemGroup>