prepend: fix ancestors order

* class.c (rb_mod_ancestors): fix ancestors order.
  [ruby-core:45919][Bug #6658] [ruby-dev:45861][Bug #6659]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36241 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Thu Jun 28 06:12:42 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* class.c (rb_mod_ancestors): fix ancestors order.
+	  [ruby-core:45919][Bug #6658] [ruby-dev:45861][Bug #6659]
+
 Wed Jun 27 21:28:59 2012  Kazuhiro NISHIYAMA  <zn@mbf.nifty.com>
 
 	* lib/racc/parser.rb: NotImplementError is not exist.

class.c

@@ -838,11 +838,22 @@ VALUE
 rb_mod_ancestors(VALUE mod)
 {
     VALUE p, ary = rb_ary_new();
+    VALUE origin = RCLASS_ORIGIN(mod);
 
-    for (p = mod; p; p = RCLASS_SUPER(p)) {
+    p = mod;
+    if (origin == mod) {
+	origin = 0;
+    }
+    else {
+	p = RCLASS_SUPER(p);
+    }
+    for (; p; p = RCLASS_SUPER(p)) {
 	if (FL_TEST(p, FL_SINGLETON))
 	    continue;
-	if (BUILTIN_TYPE(p) == T_ICLASS) {
+	if (p == origin) {
+	    rb_ary_push(ary, mod);
+	}
+	else if (BUILTIN_TYPE(p) == T_ICLASS) {
 	    rb_ary_push(ary, RBASIC(p)->klass);
 	}
 	else {

test/ruby/test_module.rb

@@ -1273,9 +1273,9 @@ class TestModule < Test::Unit::TestCase
 
   def test_prepend_inheritance
     bug6654 = '[ruby-core:45914]'
-    a = Module.new
+    a = labeled_module("a")
-    b = Module.new {include a}
+    b = labeled_module("b") {include a}
-    c = Class.new {prepend b}
+    c = labeled_class("c") {prepend b}
     assert_operator(c, :<, b, bug6654)
     assert_operator(c, :<, a, bug6654)
   end
@@ -1299,4 +1299,32 @@ class TestModule < Test::Unit::TestCase
       end
     end
   end
+
+  def test_prepend_class_ancestors
+    bug6658 = '[ruby-core:45919]'
+    m = labeled_module("m")
+    c = labeled_class("c") {prepend m}
+    assert_equal([m, c], c.ancestors[0, 2], bug6658)
+  end
+
+  def test_prepend_module_ancestors
+    bug6659 = '[ruby-dev:45861]'
+    m0 = labeled_module("m0")
+    m1 = labeled_module("m1") {prepend m0}
+    assert_equal([m0, m1], m1.ancestors, bug6659)
+  end
+
+  def labeled_module(name, &block)
+    Module.new do
+      singleton_class.class_eval {define_method(:to_s) {name}}
+      class_eval(&block) if block
+    end
+  end
+
+  def labeled_class(name, superclass = Object, &block)
+    Class.new(superclass) do
+      singleton_class.class_eval {define_method(:to_s) {name}}
+      class_eval(&block) if block
+    end
+  end
 end