Improve director unwrap detection for the return type

Resolve the return type to correctly determine if the type is a pointer or
reference to a director class.

SwigType_refptr_count_return() recently added as a simpler fix is no
longer needed.

The conventional approach of using the "type" rather than "decl" to
analyse the return type is used instead too.

Issue #1823

Source/Modules/directors.cxx

@@ -233,3 +233,38 @@ void Swig_director_parms_fixup(ParmList *parms) {
   }
 }
 
+/* -----------------------------------------------------------------------------
+ * Swig_director_can_unwrap()
+ *
+ * Determine whether a function's return type can be returned as an existing
+ * target language object instead of creating a new target language object.
+ * Must be a director class and only for return by pointer or reference only
+ * (not by value or by pointer to pointer etc).
+ * ----------------------------------------------------------------------------- */
+
+bool Swig_director_can_unwrap(Node *n) {
+
+  // FIXME: this will not try to unwrap directors returned as non-director
+  //        base class pointers!
+
+  bool unwrap = false;
+
+  String *type = Getattr(n, "type");
+  SwigType *t = SwigType_typedef_resolve_all(type);
+  SwigType *t1 = SwigType_strip_qualifiers(t);
+  SwigType *prefix = SwigType_prefix(t1);
+
+  if (Strcmp(prefix, "p.") == 0 || Strcmp(prefix, "r.") == 0) {
+    Node *parent = Swig_methodclass(n);
+    Node *module = Getattr(parent, "module");
+    Node *target = Swig_directormap(module, t1);
+    if (target)
+      unwrap = true;
+  }
+
+  Delete(prefix);
+  Delete(t1);
+  Delete(t);
+
+  return unwrap;
+}

Source/Modules/python.cxx

@@ -3150,25 +3150,9 @@ public:
 	  Replaceall(tm, "$owner", "0");
 	}
       }
-      // FIXME: this will not try to unwrap directors returned as non-director
-      //        base class pointers!
 
-      /* New addition to unwrap director return values so that the original
-       * python object is returned instead.
-       */
-#if 1
-      int unwrap = 0;
-      String *decl = Getattr(n, "decl");
-      if (SwigType_refptr_count_return(decl) == 1) {
-	String *type = Getattr(n, "type");
-	//Node *classNode = Swig_methodclass(n);
-	//Node *module = Getattr(classNode, "module");
-	Node *module = Getattr(parent, "module");
-	Node *target = Swig_directormap(module, type);
-	if (target)
-	  unwrap = 1;
-      }
-      if (unwrap) {
+      // Unwrap return values that are director classes so that the original Python object is returned instead. 
+      if (!constructor && Swig_director_can_unwrap(n)) {
 	Wrapper_add_local(f, "director", "Swig::Director *director = 0");
 	Printf(f->code, "director = SWIG_DIRECTOR_CAST(%s);\n", Swig_cresult_name());
 	Append(f->code, "if (director) {\n");
@@ -3180,9 +3164,7 @@ public:
       } else {
 	Printf(f->code, "%s\n", tm);
       }
-#else
-      Printf(f->code, "%s\n", tm);
-#endif
+
       Delete(tm);
     } else {
       Swig_warning(WARN_TYPEMAP_OUT_UNDEF, input_file, line_number, "Unable to use return type %s in function %s.\n", SwigType_str(d, 0), name);

Source/Modules/ruby.cxx

@@ -1871,24 +1871,8 @@ public:
             else
               Replaceall(tm, "$owner", "0");
 
-#if 1
-            // FIXME: this will not try to unwrap directors returned as non-director
-            //        base class pointers!
-
-            /* New addition to unwrap director return values so that the original
-             * Ruby object is returned instead. 
-             */
-            bool unwrap = false;
-            String *decl = Getattr(n, "decl");
-            if (SwigType_refptr_count_return(decl) == 1) {
-              String *type = Getattr(n, "type");
-              Node *parent = Swig_methodclass(n);
-              Node *modname = Getattr(parent, "module");
-              Node *target = Swig_directormap(modname, type);
-              if (target)
-                unwrap = true;
-            }
-            if (unwrap) {
+            // Unwrap return values that are director classes so that the original Ruby object is returned instead. 
+            if (Swig_director_can_unwrap(n)) {
               Wrapper_add_local(f, "director", "Swig::Director *director = 0");
               Printf(f->code, "director = dynamic_cast<Swig::Director *>(%s);\n", Swig_cresult_name());
               Printf(f->code, "if (director) {\n");
@@ -1900,9 +1884,7 @@ public:
             } else {
               Printf(f->code, "%s\n", tm);
             }
-#else
-            Printf(f->code, "%s\n", tm);
-#endif
+
             Delete(tm);
           } else {
             Swig_warning(WARN_TYPEMAP_OUT_UNDEF, input_file, line_number, "Unable to use return type %s.\n", SwigType_str(t, 0));

Source/Modules/swigmod.h

@@ -405,6 +405,7 @@ String *Swig_method_decl(SwigType *return_base_type, SwigType *decl, const_Strin
 String *Swig_director_declaration(Node *n);
 void Swig_director_emit_dynamic_cast(Node *n, Wrapper *f);
 void Swig_director_parms_fixup(ParmList *parms);
+bool Swig_director_can_unwrap(Node *n);
 /* directors.cxx end */
 
 /* Utilities */