* transcode.c (str_encode_bang, encoded_dup): if nothing was

transcoded, just set encoding but leave coderange unchanged as
  forcee_encoding.  [ruby-core:43557][Bug #6190]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@35112 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Thu Mar 22 23:14:36 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* transcode.c (str_encode_bang, encoded_dup): if nothing was
+	  transcoded, just set encoding but leave coderange unchanged as
+	  forcee_encoding.  [ruby-core:43557][Bug #6190]
+
 Thu Mar 22 22:30:44 2012  Hiroshi Shirosaki  <h.shirosaki@gmail.com>
 
 	* io.c (static int io_fflush): add the definition.

test/ruby/test_m17n.rb

@@ -1410,6 +1410,14 @@ class TestM17N < Test::Unit::TestCase
     assert_equal(true, s.valid_encoding?)
     s << "\xff".force_encoding("utf-16be")
     assert_equal(false, s.valid_encoding?, bug4018)
+
+    bug6190 = '[ruby-core:43557]'
+    s = "\xe9"
+    s = s.encode("utf-8", "utf-8")
+    assert_equal(false, s.valid_encoding?, bug6190)
+    s = "\xe9"
+    s.encode!("utf-8", "utf-8")
+    assert_equal(false, s.valid_encoding?, bug6190)
   end
 
   def test_getbyte

transcode.c

@@ -2785,6 +2785,10 @@ str_encode_bang(int argc, VALUE *argv, VALUE str)
     encidx = str_transcode(argc, argv, &newstr);
 
     if (encidx < 0) return str;
+    if (newstr == str) {
+	rb_enc_associate_index(str, encidx);
+	return str;
+    }
     rb_str_shared_replace(str, newstr);
     return str_encode_associate(str, encidx);
 }
@@ -2871,6 +2875,8 @@ encoded_dup(VALUE newstr, VALUE str, int encidx)
     if (encidx < 0) return rb_str_dup(str);
     if (newstr == str) {
 	newstr = rb_str_dup(str);
+	rb_enc_associate_index(newstr, encidx);
+	return newstr;
     }
     else {
 	RBASIC(newstr)->klass = rb_obj_class(str);