3 files changed, 9 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 0cb44ddd54..6700e1f6f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Thu Jun  6 00:05:08 2013  Akinori MUSHA  <knu@iDaemons.org>
+
+	* string.c (String#b): Allow code range scan to happen later so
+	  ascii_only? on a result string returns the correct value.
+	  [ruby-core:55315] [Bug #8496]
+
 Wed Jun  5 22:40:42 2013  Shugo Maeda  <shugo@ruby-lang.org>
 
 	* lib/net/imap.rb (capability_response): should ignore trailing
diff --git a/string.c b/string.c
index 6aeb029f2f..4111e963c7 100644
--- a/string.c
+++ b/string.c
@@ -7624,7 +7624,7 @@ rb_str_b(VALUE str)
     VALUE str2 = str_alloc(rb_cString);
     str_replace_shared_without_enc(str2, str);
     OBJ_INFECT(str2, str);
-    ENC_CODERANGE_SET(str2, ENC_CODERANGE_VALID);
+    ENC_CODERANGE_CLEAR(str2);
     return str2;
 }
 
diff --git a/test/ruby/test_m17n.rb b/test/ruby/test_m17n.rb
index 98f79b3f76..edc8e4c28f 100644
--- a/test/ruby/test_m17n.rb
+++ b/test/ruby/test_m17n.rb
@@ -1488,6 +1488,8 @@ class TestM17N < Test::Unit::TestCase
     assert_equal(true, s.b.tainted?)
     s.untrust
     assert_equal(true, s.b.untrusted?)
+    s = "abc".b
+    assert_equal(true, s.b.ascii_only?)
   end
 
   def test_scrub