Fix String#rpartition(/re/) against a multibyte string.

* string.c (rb_str_rpartition): Fix String#rpartition(/re/)
  against a multibyte string. [Bug #8138] [ruby-dev:47183]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@39903 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Sun Mar 24 18:29:46 2013  Akinori MUSHA  <knu@iDaemons.org>
+
+	* string.c (rb_str_rpartition): Fix String#rpartition(/re/)
+	  against a multibyte string. [Bug #8138] [ruby-dev:47183]
+
 Sun Mar 24 13:42:24 2013  Narihiro Nakamura  <authornari@gmail.com>
 
 	* gc.c (GC_ENABLE_LAZY_SWEEP): new macro to switch lazy sweeping

string.c

@@ -7542,9 +7542,10 @@ rb_str_rpartition(VALUE str, VALUE sep)
     if (regex) {
 	sep = rb_reg_nth_match(0, rb_backref_get());
     }
-    return rb_ary_new3(3, rb_str_substr(str, 0, pos),
+    return rb_ary_new3(3, rb_str_subseq(str, 0, pos),
 		          sep,
-		          rb_str_substr(str,pos+str_strlen(sep,STR_ENC_GET(sep)),RSTRING_LEN(str)));
+		          rb_str_subseq(str, pos+RSTRING_LEN(sep),
+					     RSTRING_LEN(str)-pos-RSTRING_LEN(sep)));
 }
 
 /*

test/ruby/test_string.rb

@@ -1998,6 +1998,9 @@ class TestString < Test::Unit::TestCase
       s = S("a:".force_encoding(enc))
       assert_equal([enc]*3, s.partition("|").map(&:encoding), bug6206)
     end
+
+    assert_equal(["\u30E6\u30FC\u30B6", "@", "\u30C9\u30E1.\u30A4\u30F3"],
+      "\u30E6\u30FC\u30B6@\u30C9\u30E1.\u30A4\u30F3".partition(/[@.]/))
   end
 
   def test_rpartition
@@ -2013,6 +2016,10 @@ class TestString < Test::Unit::TestCase
       s = S("a:".force_encoding(enc))
       assert_equal([enc]*3, s.rpartition("|").map(&:encoding), bug6206)
     end
+
+    bug8138 = '[ruby-dev:47183]'
+    assert_equal(["\u30E6\u30FC\u30B6@\u30C9\u30E1", ".", "\u30A4\u30F3"],
+      "\u30E6\u30FC\u30B6@\u30C9\u30E1.\u30A4\u30F3".rpartition(/[@.]/), bug8138)
   end
 
   def test_setter