From ab6efa5be2f5a2fb1b5a05a90f398b27ea52617a Mon Sep 17 00:00:00 2001
From: nobu <nobu@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Wed, 8 Jan 2014 06:55:24 +0000
Subject: [PATCH] object.c: hash value from objid with salt

* hash.c (rb_objid_hash): return hash value from object ID with a
  salt, extract from rb_any_hash().
* object.c (rb_obj_hash): return same value as rb_any_hash().
  fix r44125.  [ruby-core:59638] [Bug #9381]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44525 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog              |  8 ++++++++
 hash.c                 | 15 ++++++++++++---
 object.c               |  3 ++-
 test/ruby/test_hash.rb | 21 +++++++++++++++++++++
 4 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a0a2ba0eb7..89304de430 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+Wed Jan  8 15:55:21 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* hash.c (rb_objid_hash): return hash value from object ID with a
+	  salt, extract from rb_any_hash().
+
+	* object.c (rb_obj_hash): return same value as rb_any_hash().
+	  fix r44125.  [ruby-core:59638] [Bug #9381]
+
 Wed Jan  8 13:12:41 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* lib/timeout.rb (Timeout::ExitException.catch): pass arguments
diff --git a/hash.c b/hash.c
index 0eca4b99a4..51ba38dd58 100644
--- a/hash.c
+++ b/hash.c
@@ -122,6 +122,8 @@ rb_hash(VALUE obj)
     return hval;
 }
 
+st_index_t rb_objid_hash(st_index_t index);
+
 static st_index_t
 rb_any_hash(VALUE a)
 {
@@ -130,9 +132,7 @@ rb_any_hash(VALUE a)
 
     if (SPECIAL_CONST_P(a)) {
 	if (a == Qundef) return 0;
-	hnum = rb_hash_start((st_index_t)a);
-	hnum = rb_hash_uint(hnum, (st_index_t)rb_any_hash);
-	hnum = rb_hash_end(hnum);
+	hnum = rb_objid_hash((st_index_t)a);
     }
     else if (BUILTIN_TYPE(a) == T_STRING) {
 	hnum = rb_str_hash(a);
@@ -145,6 +145,15 @@ rb_any_hash(VALUE a)
     return (st_index_t)RSHIFT(hnum, 1);
 }
 
+st_index_t
+rb_objid_hash(st_index_t index)
+{
+    st_index_t hnum = rb_hash_start(index);
+    hnum = rb_hash_uint(hnum, (st_index_t)rb_any_hash);
+    hnum = rb_hash_end(hnum);
+    return hnum;
+}
+
 static const struct st_hash_type objhash = {
     rb_any_cmp,
     rb_any_hash,
diff --git a/object.c b/object.c
index e54285d8fc..1398201c83 100644
--- a/object.c
+++ b/object.c
@@ -161,6 +161,7 @@ rb_obj_equal(VALUE obj1, VALUE obj2)
 VALUE
 rb_obj_hash(VALUE obj)
 {
+    st_index_t rb_objid_hash(st_index_t index);
     VALUE oid = rb_obj_id(obj);
 #if SIZEOF_LONG == SIZEOF_VOIDP
     st_index_t index = NUM2LONG(oid);
@@ -169,7 +170,7 @@ rb_obj_hash(VALUE obj)
 #else
 # error not supported
 #endif
-    st_index_t h = rb_hash_end(rb_hash_start(index));
+    st_index_t h = rb_objid_hash(index);
     return LONG2FIX(h);
 }
 
diff --git a/test/ruby/test_hash.rb b/test/ruby/test_hash.rb
index 70c04424db..3861fde0a4 100644
--- a/test/ruby/test_hash.rb
+++ b/test/ruby/test_hash.rb
@@ -1215,6 +1215,27 @@ class TestHash < Test::Unit::TestCase
     assert_no_memory_leak([], prepare, code, bug9187)
   end
 
+  def test_wrapper_of_special_const
+    bug9381 = '[ruby-core:59638] [Bug #9381]'
+
+    wrapper = Class.new do
+      def initialize(obj)
+        @obj = obj
+      end
+
+      def hash
+        @obj.hash
+      end
+
+      def eql?(other)
+        @obj.eql?(other)
+      end
+    end
+
+    hash = {5 => bug9381}
+    assert_equal(bug9381, hash[wrapper.new(5)])
+  end
+
   class TestSubHash < TestHash
     class SubHash < Hash
       def reject(*)