From 86d46b5459cda15a616e29934b1ddfe4ec788735 Mon Sep 17 00:00:00 2001
From: shugo <shugo@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 17 Nov 2009 14:53:32 +0000
Subject: [PATCH] * vm_method.c (rb_alias): should raise TypeError if klass is
 nil.   1.instance_eval { alias to_string to_s } causes SEGV before this  
 fix. * test/ruby/test_alias.rb (test_special_const_alias): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@25826 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog               | 11 ++++++++++-
 test/ruby/test_alias.rb |  8 ++++++++
 vm_method.c             |  4 ++++
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index d720571cdb..ff3c1c0c2f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,14 @@
+Tue Nov 17 23:50:06 2009  Shugo Maeda  <shugo@ruby-lang.org>
+
+	* vm_method.c (rb_alias): should raise TypeError if klass is nil.
+	  1.instance_eval { alias to_string to_s } causes SEGV before this
+	  fix.
+
+	* test/ruby/test_alias.rb (test_special_const_alias): ditto.
+
 Tue Nov 17 17:53:53 2009  Martin Duerst  <duerst@it.aoyama.ac.jp>
 
-        * enc/big5.c, enc/trans/big5.trans, enc/trans/big5-uao-tbl.rb,
+	* enc/big5.c, enc/trans/big5.trans, enc/trans/big5-uao-tbl.rb,
 	  test/ruby/test-transcode.rb: Added Encoding 'Big5-UAO' and transcoding
 	  for it (from Tatsuya Mizuno) (see Bug #1784)
 
@@ -11,6 +19,7 @@ Tue Nov 17 16:26:24 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* vm_insnhelper.c (opt_case_dispatch_i): gets rid of type-punning
 	  calls.
+
 Mon Nov 16 15:51:53 2009  Shugo Maeda  <shugo@ruby-lang.org>
 
 	* vm_insnhelper.c (vm_call_method): protected singleton methods of
diff --git a/test/ruby/test_alias.rb b/test/ruby/test_alias.rb
index 7f8a32c529..babd763577 100644
--- a/test/ruby/test_alias.rb
+++ b/test/ruby/test_alias.rb
@@ -77,4 +77,12 @@ class TestAlias < Test::Unit::TestCase
     end
     assert_equal("ABC", x.try(:upcase), '[ruby-dev:38824]')
   end
+
+  def test_special_const_alias
+    assert_raise(TypeError) do
+      1.instance_eval do
+        alias to_string to_s
+      end
+    end
+  end
 end
diff --git a/vm_method.c b/vm_method.c
index 557583f5aa..d1c68b58f3 100644
--- a/vm_method.c
+++ b/vm_method.c
@@ -857,6 +857,10 @@ rb_alias(VALUE klass, ID name, ID def)
 {
     rb_method_entry_t *orig_me;
 
+    if (NIL_P(klass)) {
+	rb_raise(rb_eTypeError, "no class to make alias");
+    }
+
     rb_frozen_class_p(klass);
     if (klass == rb_cObject) {
 	rb_secure(4);