Revert r52872 "string.c: should not taint fstring"

This reverts commit b887c7c20ab81b50ed7cb8c7db3218c443985d6b.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@52878 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 1 insertions, 17 deletions

diff --git a/ChangeLog b/ChangeLog
index 8bd8180088..f27faf9c3d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,11 +3,6 @@ Fri Dec  4 11:22:40 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 	* thread.c (rb_thread_setname): name must be ascii-compatible, as
 	  pthread APIs do not accept legacy wide char strings.
 
-Thu Dec  3 16:02:17 2015  Nobuyoshi Nakada  <nobu@ruby-lang.org>
-
-	* string.c (rb_obj_as_string): fstring should not be infected.
-	  TODO: other frozen strings also may not be.
-
 Thu Dec  3 15:39:21 2015  SHIBATA Hiroshi  <hsbt@ruby-lang.org>
 
 	* lib/scanf.rb: fixed double words typo.
diff --git a/string.c b/string.c
index 4cb62375da..d1a051b6dd 100644
--- a/string.c
+++ b/string.c
@@ -1247,9 +1247,7 @@ rb_obj_as_string(VALUE obj)
     str = rb_funcall(obj, idTo_s, 0);
     if (!RB_TYPE_P(str, T_STRING))
 	return rb_any_to_s(obj);
-    if (!FL_SET(str, RSTRING_FSTR) && FL_ABLE(obj))
-	/* fstring must not be tainted, at least */
-	OBJ_INFECT_RAW(str, obj);
+    OBJ_INFECT(str, obj);
     return str;
 }
 
diff --git a/test/ruby/test_object.rb b/test/ruby/test_object.rb
index 27f3bd18ce..a3c71d605c 100644
--- a/test/ruby/test_object.rb
+++ b/test/ruby/test_object.rb
@@ -755,15 +755,6 @@ class TestObject < Test::Unit::TestCase
       end
     EOS
     assert_match(/\bToS\u{3042}:/, x)
-
-    name = "X".freeze
-    x = Object.new.taint
-    class<<x;self;end.class_eval {define_method(:to_s) {name}}
-    assert_same(name, x.to_s)
-    assert_not_predicate(name, :tainted?)
-    assert_raise(RuntimeError) {name.taint}
-    assert_equal("X", [x].join(""))
-    assert_not_predicate(name, :tainted?)
   end
 
   def test_inspect