* string.c (rb_memhash): zero-filled strings should return

different values.  [ruby-core:33500]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29991 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Wed Dec  1 14:36:36 2010  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (rb_memhash): zero-filled strings should return
+	  different values.  [ruby-core:33500]
+
 Wed Dec  1 14:27:49 2010  Ryan Davis  <ryand-ruby@zenspider.com>
 
 	* lib/minitest/*.rb: Imported minitest 2.0.0 r5952.

string.c

@@ -2073,7 +2073,7 @@ rb_str_prepend(VALUE str, VALUE str2)
 st_index_t
 rb_memhash(const void *ptr, long len)
 {
-    return st_hash(ptr, len, rb_hash_start(0));
+    return st_hash(ptr, len, rb_hash_start((st_index_t)len));
 }
 
 st_index_t

test/ruby/test_string.rb

@@ -727,6 +727,8 @@ class TestString < Test::Unit::TestCase
   def test_hash
     assert_equal(S("hello").hash, S("hello").hash)
     assert(S("hello").hash != S("helLO").hash)
+    bug4104 = '[ruby-core:33500]'
+    assert_not_equal(S("a").hash, S("a\0").hash, bug4104)
   end
 
   def test_hash_random