From b15ca8827e4b15d4abd682f9f1036dbd64bf487b Mon Sep 17 00:00:00 2001
From: Joao Matos <joao@tritao.eu>
Date: Tue, 10 Dec 2019 13:36:32 +0000
Subject: [PATCH] Avoid generating abstract implementations for template
 classes.

Fixes https://github.com/mono/CppSharp/issues/1268.
---
 .../Passes/GenerateAbstractImplementationsPass.cs    |  6 +++---
 tests/Common/Common.h                                | 12 ++++++++++++
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/Generator/Passes/GenerateAbstractImplementationsPass.cs b/src/Generator/Passes/GenerateAbstractImplementationsPass.cs
index 4953047d..6ae567b3 100644
--- a/src/Generator/Passes/GenerateAbstractImplementationsPass.cs
+++ b/src/Generator/Passes/GenerateAbstractImplementationsPass.cs
@@ -7,8 +7,8 @@ namespace CppSharp.Passes
     /// <summary>
     /// This pass generates internal classes that implement abstract classes.
     /// When the return type of a function is abstract, these internal
-    /// classes provide since the real type cannot be resolved while binding
-    /// an allocatable class that supports proper polymorphism.
+    /// classes are used instead since the real type cannot be resolved 
+    /// while binding an allocatable class that supports proper polymorphism.
     /// </summary>
     public class GenerateAbstractImplementationsPass : TranslationUnitPass
     {
@@ -57,7 +57,7 @@ namespace CppSharp.Passes
             if (@class.CompleteDeclaration != null)
                 return VisitClassDecl(@class.CompleteDeclaration as Class);
 
-            if (@class.IsAbstract)
+            if (@class.IsAbstract && !@class.IsTemplate)
             {
                 foreach (var ctor in from ctor in @class.Constructors
                                      where ctor.Access == AccessSpecifier.Public
diff --git a/tests/Common/Common.h b/tests/Common/Common.h
index 8cf28fab..bee5e26d 100644
--- a/tests/Common/Common.h
+++ b/tests/Common/Common.h
@@ -1537,3 +1537,15 @@ struct DerivedCovariant: public BaseCovariant {
     return PtrCovariant(new DerivedCovariant());
   }
 };
+
+// Issue: https://github.com/mono/CppSharp/issues/1268
+template <typename T>
+class AbstractClassTemplate {
+  public:
+    virtual void func() = 0;
+};
+
+class DerivedClass: public AbstractClassTemplate<int> {
+  public:
+    void func() override {}
+};