Fix SD-1841 - SolutionDir MSBuild property not defined when running project.

src/Main/Base/Project/Src/Project/Solution/Solution.cs

@@ -1193,9 +1193,9 @@ namespace ICSharpCode.SharpDevelop.Project
 			return newSolution;
 		}
 		
-		void UpdateMSBuildProperties()
+		public void UpdateMSBuildProperties()
 		{
-			MSBuildProjectCollection.SetGlobalProperty("SolutionDir", Directory);
+			MSBuildProjectCollection.SetGlobalProperty("SolutionDir", Directory + @"\");
 		}
 		
 		#endregion

src/Main/Base/Test/ICSharpCode.SharpDevelop.Tests.csproj

@@ -33,6 +33,7 @@
     <FileAlignment>4096</FileAlignment>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Microsoft.Build" />
     <Reference Include="Microsoft.VisualBasic" />
     <Reference Include="PresentationCore">
       <RequiredTargetFramework>3.0</RequiredTargetFramework>
@@ -108,6 +109,7 @@
     <Compile Include="ServiceReferences\ServiceReferencesFolderNodeTests.cs" />
     <Compile Include="ServiceReferences\ServiceReferencesProjectItemTests.cs" />
     <Compile Include="ServiceReferences\WebServiceMetadataSetTests.cs" />
+    <Compile Include="SolutionTests.cs" />
     <Compile Include="StringTagProvider\MockProjectForTagProvider.cs" />
     <Compile Include="StringTagProvider\NullProjectStringTagProviderTestFixture.cs" />
     <Compile Include="StringTagProvider\ProjectTagsTestFixture.cs" />

src/Main/Base/Test/SolutionTests.cs

@@ -0,0 +1,38 @@
+// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)
+
+using System;
+using ICSharpCode.SharpDevelop.Project;
+using Microsoft.Build.Execution;
+using NUnit.Framework;
+using Rhino.Mocks;
+
+namespace ICSharpCode.SharpDevelop.Tests
+{
+	[TestFixture]
+	public class SolutionTests
+	{
+		Solution solution;
+		
+		void CreateSolution()
+		{
+			IProjectChangeWatcher fakeWatcher = MockRepository.GenerateStub<IProjectChangeWatcher>();
+			solution = new Solution(fakeWatcher);
+		}
+		
+		[Test]
+		public void UpdateMSBuildProperties_SolutionHasFileName_SolutionDefinesSolutionDirMSBuildPropertyWithDirectoryEndingInForwardSlash()
+		{
+			CreateSolution();
+			solution.FileName = @"d:\projects\MyProject\MySolution.sln";
+			
+			solution.UpdateMSBuildProperties();
+			
+			ProjectPropertyInstance property = solution.MSBuildProjectCollection.GetGlobalProperty("SolutionDir");
+			string solutionDir = property.EvaluatedValue;
+			
+			string expectedSolutionDir = @"d:\projects\MyProject\";
+			Assert.AreEqual(expectedSolutionDir, solutionDir);
+		}
+	}
+}