From a6ec2584527fb4d6f3a65a2dd16dc02eabdfcec6 Mon Sep 17 00:00:00 2001
From: naruse <naruse@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Tue, 6 Nov 2012 00:50:02 +0000
Subject: [PATCH] * string.c (rb_str_b): Add String#b, returning a copied
 string   whose encoding is ASCII-8BIT. [ruby-dev:45992] [Feature #6767]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@37486 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog              |  5 +++++
 NEWS                   |  4 ++++
 string.c               | 28 ++++++++++++++++++++++++++--
 test/ruby/test_m17n.rb | 10 ++++++++++
 4 files changed, 45 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index bcad80d32a..8e4b50a20d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Tue Nov  6 09:42:26 2012  NARUSE, Yui  <naruse@ruby-lang.org>
+
+	* string.c (rb_str_b): Add String#b, returning a copied string
+	  whose encoding is ASCII-8BIT. [ruby-dev:45992] [Feature #6767]
+
 Tue Nov  6 09:37:57 2012  NARUSE, Yui  <naruse@ruby-lang.org>
 
 	* ruby.c (load_file_internal): set default source encoding as
diff --git a/NEWS b/NEWS
index df737c447e..e84728065c 100644
--- a/NEWS
+++ b/NEWS
@@ -93,6 +93,10 @@ with all sufficient information, see the ChangeLog file.
       * Signal.trap raises ArgumentError when :SEGV, :BUS, :ILL, :FPE, :VTALRM
         are specified.
 
+  *String
+    * added method:
+      * added String#b returning a copied string whose encoding is ASCII-8BIT.
+
   * Struct
     * added method:
       * added Struct#to_h returning values with keys corresponding to the
diff --git a/string.c b/string.c
index ae9af6c85d..d674e8903c 100644
--- a/string.c
+++ b/string.c
@@ -602,7 +602,7 @@ rb_str_export_to_enc(VALUE str, rb_encoding *enc)
 }
 
 static VALUE
-str_replace_shared(VALUE str2, VALUE str)
+str_replace_shared_without_enc(VALUE str2, VALUE str)
 {
     if (RSTRING_LEN(str) <= RSTRING_EMBED_LEN_MAX) {
 	STR_SET_EMBED(str2);
@@ -617,8 +617,14 @@ str_replace_shared(VALUE str2, VALUE str)
 	RSTRING(str2)->as.heap.aux.shared = str;
 	FL_SET(str2, ELTS_SHARED);
     }
-    rb_enc_cr_str_exact_copy(str2, str);
+    return str2;
+}
 
+static VALUE
+str_replace_shared(VALUE str2, VALUE str)
+{
+    str_replace_shared_without_enc(str2, str);
+    rb_enc_cr_str_exact_copy(str2, str);
     return str2;
 }
 
@@ -7360,6 +7366,23 @@ rb_str_force_encoding(VALUE str, VALUE enc)
     return str;
 }
 
+/*
+ *  call-seq:
+ *     str.b   -> str
+ *
+ *  Returns a copied string whose encoding is ASCII-8BIT.
+ */
+
+static VALUE
+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);
+    return str2;
+}
+
 /*
  *  call-seq:
  *     str.valid_encoding?  -> true or false
@@ -8001,6 +8024,7 @@ Init_String(void)
 
     rb_define_method(rb_cString, "encoding", rb_obj_encoding, 0); /* in encoding.c */
     rb_define_method(rb_cString, "force_encoding", rb_str_force_encoding, 1);
+    rb_define_method(rb_cString, "b", rb_str_b, 0);
     rb_define_method(rb_cString, "valid_encoding?", rb_str_valid_encoding_p, 0);
     rb_define_method(rb_cString, "ascii_only?", rb_str_is_ascii_only_p, 0);
 
diff --git a/test/ruby/test_m17n.rb b/test/ruby/test_m17n.rb
index 7e343ab31f..bdde127840 100644
--- a/test/ruby/test_m17n.rb
+++ b/test/ruby/test_m17n.rb
@@ -1471,4 +1471,14 @@ class TestM17N < Test::Unit::TestCase
       yield(*strs)
     end
   end
+
+  def test_str_b
+    s = "\u3042"
+    assert_equal(a("\xE3\x81\x82"), s.b)
+    assert_equal(Encoding::ASCII_8BIT, s.b.encoding)
+    s.taint
+    assert_equal(true, s.b.tainted?)
+    s.untrust
+    assert_equal(true, s.b.untrusted?)
+  end
 end