4 files changed, 27 insertions, 1 deletions
diff --git a/ChangeLog b/ChangeLog
index 318996b304..6faa75a730 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Fri Mar 30 14:15:40 2012  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* string.c (str_new_empty): should copy also the encoding as an
+	  empty substring.  [ruby-dev:45441][Bug #6206]
+
 Fri Mar 30 14:14:36 2012  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* ext/date/date_core.c (datetime_s_now): [ruby-core:43256].
diff --git a/string.c b/string.c
index d0f08a3f42..134d65b822 100644
--- a/string.c
+++ b/string.c
@@ -725,6 +725,7 @@ static VALUE
 str_new_empty(VALUE str)
 {
     VALUE v = rb_str_new5(str, 0, 0);
+    rb_enc_copy(v, str);
     OBJ_INFECT(v, str);
     return v;
 }
diff --git a/test/ruby/test_string.rb b/test/ruby/test_string.rb
index faa7bd670d..4d9d172ccf 100644
--- a/test/ruby/test_string.rb
+++ b/test/ruby/test_string.rb
@@ -1164,6 +1164,12 @@ class TestString < Test::Unit::TestCase
 
     assert_equal("[2, 3]", [1,2,3].slice!(1,10000).inspect, "moved from btest/knownbug")
 
+    bug6206 = '[ruby-dev:45441]'
+    Encoding.list.each do |enc|
+      next unless enc.ascii_compatible?
+      s = S("a:".force_encoding(enc))
+      assert_equal([enc]*2, s.split(":", 2).map(&:encoding), bug6206)
+    end
   end
 
   def test_squeeze
@@ -1803,6 +1809,13 @@ class TestString < Test::Unit::TestCase
     assert_raise(TypeError) { "hello".partition(1) }
     def (hyphen = Object.new).to_str; "-"; end
     assert_equal(%w(foo - bar), "foo-bar".partition(hyphen), '[ruby-core:23540]')
+
+    bug6206 = '[ruby-dev:45441]'
+    Encoding.list.each do |enc|
+      next unless enc.ascii_compatible?
+      s = S("a:".force_encoding(enc))
+      assert_equal([enc]*3, s.partition("|").map(&:encoding), bug6206)
+    end
   end
 
   def test_rpartition
@@ -1811,6 +1824,13 @@ class TestString < Test::Unit::TestCase
     assert_raise(TypeError) { "hello".rpartition(1) }
     def (hyphen = Object.new).to_str; "-"; end
     assert_equal(%w(foo - bar), "foo-bar".rpartition(hyphen), '[ruby-core:23540]')
+
+    bug6206 = '[ruby-dev:45441]'
+    Encoding.list.each do |enc|
+      next unless enc.ascii_compatible?
+      s = S("a:".force_encoding(enc))
+      assert_equal([enc]*3, s.rpartition("|").map(&:encoding), bug6206)
+    end
   end
 
   def test_setter
diff --git a/version.h b/version.h
index 81d4a88046..ffdf96fce5 100644
--- a/version.h
+++ b/version.h
@@ -1,5 +1,5 @@
 #define RUBY_VERSION "1.9.3"
-#define RUBY_PATCHLEVEL 170
+#define RUBY_PATCHLEVEL 171
 
 #define RUBY_RELEASE_DATE "2012-03-30"
 #define RUBY_RELEASE_YEAR 2012