Fixed invalid C# code when wrapping a constant of type std::string.

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

src/Generator/Generators/CSharp/CSharpTextTemplate.cs

@@ -1188,7 +1188,13 @@ namespace CppSharp.Generators.CSharp
                 if (!string.IsNullOrWhiteSpace(marshal.Context.SupportBefore))
                     Write(marshal.Context.SupportBefore);
 
+                if (ctx.HasCodeBlock)
+                    PushIndent();
+
                 WriteLine("return {0};", marshal.Context.Return);
+
+                if (ctx.HasCodeBlock)
+                    WriteCloseBraceIndent();
             }
 
             WriteCloseBraceIndent();

tests/CSharp/AnotherUnit.cpp

@@ -7,4 +7,5 @@ void functionInAnotherUnit()
 namespace HasFreeConstant
 {
     extern const int DLL_API FREE_CONSTANT_IN_NAMESPACE = 5;
+//    extern const std::string DLL_API STD_STRING_CONSTANT = "test";
 }

tests/CSharp/AnotherUnit.h

@@ -1,4 +1,5 @@
 #include "../Tests.h"
+//#include <string>
 
 void DLL_API functionInAnotherUnit();
 
@@ -15,4 +16,5 @@ class ForwardInOtherUnitButSameModule
 namespace HasFreeConstant
 {
     extern const int DLL_API FREE_CONSTANT_IN_NAMESPACE;
+//    extern const std::string DLL_API STD_STRING_CONSTANT;
 }

tests/CSharp/CSharp.Tests.cs

@@ -520,6 +520,14 @@ public unsafe class CSharpTests : GeneratorTestFixture
         }
     }
 
+    [Test, Ignore("We need symbols for std::string to invoke and auto-compilation of exported templates is not added yet.")]
+    public void TestStdStringConstant()
+    {
+        //Assert.That(CSharp.HasFreeConstant.AnotherUnit.STD_STRING_CONSTANT, Is.EqualTo("test"));
+        // check a second time to ensure it hasn't been improperly freed
+        //Assert.That(CSharp.HasFreeConstant.AnotherUnit.STD_STRING_CONSTANT, Is.EqualTo("test"));
+    }
+
     // HACK: the completion of types is temporarily suspended because of problems with QtWidgets
     [Test, Ignore]
     public void TestTemplateInternals()

tests/Common/Common.Tests.cs

@@ -633,8 +633,7 @@ public class CommonTests : GeneratorTestFixture
         }
     }
 
-    // ignored until we add automatic compilation for templates
-    [Test, Ignore]
+    [Test, Ignore("We need symbols for std::string to invoke and auto-compilation of exported templates is not added yet.")]
     public void TestStdString()
     {
         using (var hasStdString = new HasStdString())