Generate valid C# when passing a const ref to char

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

src/Generator/Generators/CSharp/CSharpMarshal.cs

@@ -557,8 +557,7 @@ namespace CppSharp.Generators.CSharp
                 if (Context.Context.Options.MarshalCharAsManagedChar &&
                     primitive == PrimitiveType.Char)
                 {
-                    Context.Return.Write($"({typePrinter.PrintNative(pointer)}) ");
+                    Context.Return.Write($"({typePrinter.PrintNative(pointer)}) &{param.Name}");
-                    Context.Return.Write(param.Name);
                     return true;
                 }
 

tests/CSharp/CSharp.Tests.cs

@@ -94,7 +94,6 @@ public unsafe class CSharpTests : GeneratorTestFixture
         {
         }
 
-        CSharp.CSharp.ReturnCharPointer();
         int value = 5;
         IntPtr intPtr = CSharp.CSharp.RValueReferenceToPointer((void**) &value);
         Assert.That((int) intPtr, Is.EqualTo(value));
@@ -103,6 +102,14 @@ public unsafe class CSharpTests : GeneratorTestFixture
 #pragma warning restore 0219
     }
 
+    [Test]
+    public void TestReturnCharPointer()
+    {
+        Assert.That(new IntPtr(CSharp.CSharp.ReturnCharPointer()), Is.EqualTo(IntPtr.Zero));
+        const char z = 'z';
+        Assert.That(*CSharp.CSharp.TakeConstCharRef(z), Is.EqualTo(z));
+    }
+
     [Test]
     public void TestIndexer()
     {

tests/CSharp/CSharp.cpp

@@ -1566,6 +1566,11 @@ char* returnCharPointer()
     return 0;
 }
 
+char* takeConstCharRef(const char& c)
+{
+    return const_cast<char*>(&c);
+}
+
 const char*& takeConstCharStarRef(const char*& c)
 {
     return c;

tests/CSharp/CSharp.h

@@ -1312,6 +1312,7 @@ public:
 
 DLL_API void va_listFunction(va_list v);
 DLL_API char* returnCharPointer();
+DLL_API char* takeConstCharRef(const char& c);
 DLL_API const char*& takeConstCharStarRef(const char*& c);
 DLL_API const void*& rValueReferenceToPointer(void*&& v);