Mark nil/true/false as frozen

Yorick Peterse · Yorick Peterse · commit 6580956db009 · 2015-07-24T22:14:12.000+02:00
Interesting enough MRI still lets you define methods on these objects
even when they're frozen. For example, this works just fine:

    def nil.foo
    end

    nil.foo
diff --git a/vm/builtin/object.cpp b/vm/builtin/object.cpp
@@ -167,9 +167,9 @@ namespace rubinius {
   Object* Object::frozen_p(STATE) {
     if(reference_p()) {
       return RBOOL(is_frozen_p());
-    } else if(try_as<Symbol>(this)) {
+    } else if(try_as<Symbol>(this) || try_as<Fixnum>(this)) {
       return cTrue;
-    } else if(try_as<Fixnum>(this)) {
+    } else if(this->nil_p() || this->true_p() || this->false_p()) {
       return cTrue;
     } else {
       LookupTable* tbl = try_as<LookupTable>(G(external_ivars)->fetch(state, this));
