properly remove <Module> during decompilation process

ICSharpCode.Decompiler/CSharp/CSharpDecompiler.cs

@@ -87,15 +87,22 @@ namespace ICSharpCode.Decompiler.CSharp
 		public SyntaxTree DecompileWholeModuleAsSingleFile()
 		{
 			SyntaxTree syntaxTree = new SyntaxTree();
-			foreach (var g in compilation.MainAssembly.TopLevelTypeDefinitions.GroupBy(t => t.Namespace))
-			{
+			foreach (var g in compilation.MainAssembly.TopLevelTypeDefinitions.GroupBy(t => t.Namespace)) {
+				AstNode groupNode;
+				if (string.IsNullOrEmpty(g.Key)) {
+					groupNode = syntaxTree;
+				} else {
 					NamespaceDeclaration ns = new NamespaceDeclaration(g.Key);
-				foreach (var typeDef in g)
-				{
+					syntaxTree.AddChild(ns, SyntaxTree.MemberRole);
+					groupNode = ns;
+				}
+				
+				foreach (var typeDef in g) {
+					if (typeDef.Name == "<Module>" && typeDef.Members.Count == 0)
+						continue;
 					var typeDecl = Decompile(typeDef);
-					ns.AddMember(typeDecl);
+					groupNode.AddChild(typeDecl, SyntaxTree.MemberRole);
 				}
-				syntaxTree.AddChild(ns, SyntaxTree.MemberRole);
 			}
 			return syntaxTree;
 		}

ICSharpCode.Decompiler/Tests/Helpers/RemoveEmptyNamespace.cs

@@ -1,26 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using ICSharpCode.NRefactory.CSharp;
-
-namespace ICSharpCode.Decompiler.Tests.Helpers
-{
-	class RemoveEmptyNamespace : DepthFirstAstVisitor<object, object>
-	{
-		public override object VisitNamespaceDeclaration(NamespaceDeclaration namespaceDeclaration, object data)
-		{
-			if (namespaceDeclaration.FullName.Length == 0) {
-				namespaceDeclaration.Remove();
-				return null;
-			}
-			return base.VisitNamespaceDeclaration(namespaceDeclaration, data);
-		}
-
-		public void Run(AstNode node)
-		{
-			node.AcceptVisitor(this, null);
-		}
-	}
-}

ICSharpCode.Decompiler/Tests/Helpers/Tester.cs

@@ -58,7 +58,6 @@ namespace ICSharpCode.Decompiler.Tests.Helpers
 			CSharpDecompiler decompiler = new CSharpDecompiler(AssemblyDefinition.ReadAssembly(assemblyFileName).MainModule);
 			var syntaxTree = decompiler.DecompileWholeModuleAsSingleFile();
 			new Helpers.RemoveCompilerAttribute().Run(syntaxTree);
-			new Helpers.RemoveEmptyNamespace().Run(syntaxTree);
 			
 			StringWriter output = new StringWriter();
 			var visitor = new CSharpOutputVisitor(output, FormattingOptionsFactory.CreateSharpDevelop());

ICSharpCode.Decompiler/Tests/ICSharpCode.Decompiler.Tests.csproj

@@ -90,7 +90,6 @@
     <Compile Include="ExceptionHandling.cs" />
     <Compile Include="Helpers\CodeAssert.cs" />
     <Compile Include="Helpers\RemoveCompilerAttribute.cs" />
-    <Compile Include="Helpers\RemoveEmptyNamespace.cs" />
     <Compile Include="Helpers\Tester.cs" />
     <Compile Include="TestCases\HelloWorld.cs" />
     <Compile Include="TestRunner.cs" />