Added test that shows a problem in the 'abstract detection method' when virtual base classes are used (in different order)

git-svn-id: https://swig.svn.sourceforge.net/svnroot/swig/trunk/SWIG@4378 626c5289-ae23-0410-ae9c-e8d60b6d4f22

Examples/test-suite/abstract_virtual.i

@@ -0,0 +1,53 @@
+%module abstract_virtual
+
+%inline %{
+  struct A 
+  {
+    virtual int foo() = 0;
+  };
+ 
+  struct B : virtual A
+  {
+    int foo() 
+    {
+      return 0;
+    }
+  };
+  
+  struct C: virtual A
+  {
+  protected:
+    C()
+    {
+    }
+  };
+
+  //
+  // This case works
+  //
+  struct D : B, C
+  {
+    D()
+    {
+    }
+  };
+
+  //
+  // This case doesn't work.
+  // It seems the is_abstract function doesn't
+  // navigate the entire set of base classes,
+  // and therefore, it doesn't detect B::foo()
+  //
+#ifdef SWIG
+  // Uncommenting this line, of course, make it works
+  // %feature("notabstract") E;
+#endif
+  //
+  struct E : C, B
+  {
+    E()
+    {
+    }    
+  };
+%}
+