Fixed the generation of a null check before returning a value.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>

src/Generator/Generators/CSharp/CSharpMarshal.cs

@@ -250,10 +250,12 @@ namespace CppSharp.Generators.CSharp
         {
             var ctx = Context as CSharpMarshalContext;
 
-            string instance = Context.ReturnVarName;
+            var instance = Context.ReturnVarName;
 
+            @class = @class.OriginalClass ?? @class;
+            Type returnType = Context.ReturnType.Type.Desugar();
             if (@class.IsRefType &&
-                (Context.ReturnType.Qualifiers.IsConst || !Context.ReturnType.Type.IsAddress()) &&
+                (Context.ReturnType.Qualifiers.IsConst || !returnType.IsAddress()) &&
                 (!Context.Driver.Options.GenerateAbstractImpls || !@class.IsAbstract))
             {
                 var instanceName = Generator.GeneratedIdentifier("instance");
@@ -299,16 +301,16 @@ namespace CppSharp.Generators.CSharp
 
                 instance = instanceName;
             }
+            
+            var type = QualifiedIdentifier(@class) +
+                (Context.Driver.Options.GenerateAbstractImpls && @class.IsAbstract ?
+                    "Internal" : "");
 
-            if (@class.IsRefType)
-                Context.Return.Write("({0} == IntPtr.Zero) ? null : ",
-                    instance);
+            if (returnType.IsAddress())
+                Context.Return.Write("({0} == IntPtr.Zero) ? {1} : ", instance,
+                    @class.IsRefType ? "null" : string.Format("new {0}()", type));
 
-            Context.Return.Write("new {0}({1})",
-                QualifiedIdentifier(@class.OriginalClass ?? @class) +
-                (Context.Driver.Options.GenerateAbstractImpls && @class.IsAbstract ?
-                    "Internal" : ""),
-                instance);
+            Context.Return.Write("new {0}({1})", type, instance);
 
             return true;
         }

tests/TypeMaps/QList.cs

@@ -0,0 +1,57 @@
+using CppSharp.AST.Extensions;
+using CppSharp.Generators;
+using CppSharp.Generators.CLI;
+using CppSharp.Generators.CSharp;
+using CppSharp.Types;
+
+namespace TypeMaps.Gen
+{
+    [TypeMap("QList")]
+    public class QList : TypeMap
+    {
+        public override bool DoesMarshalling
+        {
+            get { return false; }
+        }
+
+        public override string CLISignature(CLITypePrinterContext ctx)
+        {
+            return "TypeMaps::QList^";
+        }
+
+        public override void CLIMarshalToManaged(MarshalContext ctx)
+        {
+        }
+
+        public override void CLIMarshalToNative(MarshalContext ctx)
+        {
+        }
+
+        public override string CSharpSignature(CSharpTypePrinterContext ctx)
+        {
+            if (ctx.CSharpKind == CSharpTypePrinterContextKind.Native)
+            {
+                if (Type.IsAddress())
+                {
+                    return "QList.Internal*";
+                }
+                return "QList.Internal";
+            }
+            return "QList";
+        }
+
+        public override void CSharpMarshalToManaged(MarshalContext ctx)
+        {
+        }
+
+        public override void CSharpMarshalToNative(MarshalContext ctx)
+        {
+        }
+
+        public override void CSharpMarshalCopyCtorToManaged(MarshalContext ctx)
+        {
+            ctx.SupportBefore.WriteLine("var __instance = new {0}.Internal();", ctx.ReturnType);
+            ctx.SupportBefore.WriteLine("__instance.i = {0}.i;", ctx.ReturnVarName);
+        }
+    }
+}

tests/TypeMaps/TypeMaps.cpp

@@ -0,0 +1,11 @@
+#include "TypeMaps.h"
+#include <string.h>
+
+QList::QList() : i(5)
+{
+}
+
+QList HasQList::getList()
+{
+    return list;
+}

tests/TypeMaps/TypeMaps.cs

@@ -0,0 +1,40 @@
+using System.Linq;
+using CppSharp.AST;
+using CppSharp.Generators;
+using CppSharp.Utils;
+
+namespace CppSharp.Tests
+{
+    public class TypeMaps : GeneratorTest
+    {
+        public TypeMaps(GeneratorKind kind)
+            : base("TypeMaps", kind)
+        {
+
+        }
+
+        public override void SetupPasses(Driver driver)
+        {
+            if (driver.Options.IsCSharpGenerator)
+                driver.Options.GenerateAbstractImpls = true;
+            driver.Options.GenerateVirtualTables = true;
+            driver.Options.GenerateCopyConstructors = true;
+            driver.Options.MarshalCharAsManagedChar = true;
+            driver.Options.GenerateProperties = true;
+            driver.Options.GenerateConversionOperators = true;
+        }
+
+        public override void Preprocess(Driver driver, ASTContext ctx)
+        {
+            ctx.SetClassAsValueType("HasQList");
+            ctx.FindCompleteClass("QList").Constructors.First(c => c.IsCopyConstructor).GenerationKind = GenerationKind.None;
+            ctx.IgnoreClassWithName("IgnoredType");
+        }
+
+        public static void Main(string[] args)
+        {
+            ConsoleDriver.Run(new TypeMaps(GeneratorKind.CLI));
+            ConsoleDriver.Run(new TypeMaps(GeneratorKind.CSharp));
+        }
+    }
+}

tests/TypeMaps/TypeMaps.h

@@ -0,0 +1,16 @@
+#include "../Tests.h"
+
+class DLL_API QList
+{
+public:
+    QList();
+    int i;
+};
+
+class DLL_API HasQList
+{
+public:
+    QList getList();
+private:
+    QList list;
+};

tests/TypeMaps/premake4.lua

@@ -0,0 +1,2 @@
+group "Tests/TypeMaps"
+  SetupTestProject("TypeMaps")