Fixed the generation of dependent virtual methods.

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

src/Generator/Generators/CSharp/CSharpSources.cs

@@ -424,7 +424,7 @@ namespace CppSharp.Generators.CSharp
                     var dict = $@"global::System.Collections.Concurrent.ConcurrentDictionary<IntPtr, {
                         printedClass}>";
                     WriteLine("internal static readonly {0} NativeToManagedMap = new {0}();", dict);
-                    WriteLine("protected void*[] __OriginalVTables;");
+                    WriteLine("protected internal void*[] __OriginalVTables;");
                 }
                 PopBlock(NewLineKind.BeforeNextBlock);
             }
@@ -2272,7 +2272,10 @@ namespace CppSharp.Generators.CSharp
 
         public override void GenerateMethodSpecifier(Method method, Class @class)
         {
-            if (method.IsVirtual && !method.IsGeneratedOverride() && !method.IsOperator && !method.IsPure)
+            bool isTemplateMethod = method.Parameters.Any(
+                p => p.Kind == ParameterKind.Extension);
+            if (method.IsVirtual && !method.IsGeneratedOverride() &&
+                !method.IsOperator && !method.IsPure && !isTemplateMethod)
                 Write("virtual ");
 
             var isBuiltinOperator = method.IsOperator &&
@@ -2573,11 +2576,19 @@ namespace CppSharp.Generators.CSharp
             var i = VTables.GetVTableIndex(@virtual);
             int vtableIndex = 0;
             var @class = (Class) method.Namespace;
+            var thisParam = method.Parameters.Find(
+                p => p.Kind == ParameterKind.Extension);
+            if (thisParam != null)
+                @class = (Class) method.OriginalFunction.Namespace;
+
             if (Context.ParserOptions.IsMicrosoftAbi)
                 vtableIndex = @class.Layout.VFTables.IndexOf(@class.Layout.VFTables.Where(
                     v => v.Layout.Components.Any(c => c.Method == @virtual)).First());
-            WriteLine("var {0} = *(void**) ((IntPtr) __OriginalVTables[{1}] + {2} * {3});",
-                Helpers.SlotIdentifier, vtableIndex, i, Context.TargetInfo.PointerWidth / 8);
+
+            WriteLine($@"var {Helpers.SlotIdentifier} = *(void**) ((IntPtr) {
+                (thisParam != null ? $"{thisParam.Name}."
+                : string.Empty)}__OriginalVTables[{vtableIndex}] + {i} * {
+                Context.TargetInfo.PointerWidth / 8});");
             if (method.IsDestructor && @class.IsAbstract)
             {
                 WriteLine("if ({0} != null)", Helpers.SlotIdentifier);

tests/CSharp/CSharp.Tests.cs

@@ -736,7 +736,15 @@ public unsafe class CSharpTests : GeneratorTestFixture
     {
         using (var virtualTemplate = new VirtualTemplate<int>())
         {
-            Assert.That(virtualTemplate.Function, Is.EqualTo(5));
+            Assert.That(virtualTemplate.Function(), Is.EqualTo(5));
+            int i = 15;
+            Assert.That(*virtualTemplate.Function(ref i), Is.EqualTo(15));
+        }
+        using (var virtualTemplate = new VirtualTemplate<bool>())
+        {
+            Assert.That(virtualTemplate.Function(), Is.EqualTo(5));
+            bool b = true;
+            Assert.That(*virtualTemplate.Function(ref b), Is.EqualTo(true));
         }
     }
 
@@ -1240,9 +1248,6 @@ public unsafe class CSharpTests : GeneratorTestFixture
 
     private class OverrideVirtualTemplate : VirtualTemplate<int>
     {
-        public override int Function
-        {
-            get { return 10; }
-        }
+        public override int Function() => 10;
     }
 }

tests/CSharp/CSharpTemplates.h

@@ -442,6 +442,7 @@ public:
     VirtualTemplate(OptionalTemplateArgs<T> optionalTemplateArgs);
     virtual ~VirtualTemplate();
     virtual int function();
+    virtual T* function(T* t);
     DependentValueFields<float> fieldWithSpecializationType;
 };
 
@@ -471,6 +472,12 @@ int VirtualTemplate<T>::function()
     return 5;
 }
 
+template <typename T>
+T* VirtualTemplate<T>::function(T* t)
+{
+    return t;
+}
+
 class DLL_API HasVirtualTemplate
 {
 public: