diff --git a/ChangeLog b/ChangeLog
index 67c014fcda..5153173153 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Jul  8 16:47:03 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* file.c (rb_file_s_basename): returns new string instead of
+	  shared string from FilePathStringValue().  [ruby-core:24199]
+
 2009-07-07  Eric Hodel  <drbrain@segment7.net>
 
 	* ext/.document:  Update with extensions that appear to have
diff --git a/file.c b/file.c
index 050cbd2d64..9c9da582e8 100644
--- a/file.c
+++ b/file.c
@@ -3014,7 +3014,7 @@ rb_file_s_basename(int argc, VALUE *argv)
     }
     FilePathStringValue(fname);
     if (RSTRING_LEN(fname) == 0 || !*(name = RSTRING_PTR(fname)))
-	return fname;
+	return rb_str_new_shared(fname);
     name = skipprefix(name);
 #if defined DOSISH_DRIVE_LETTER || defined DOSISH_UNC
     root = name;
@@ -3056,7 +3056,7 @@ rb_file_s_basename(int argc, VALUE *argv)
 	if (NIL_P(fext) || !(f = rmext(p, n, StringValueCStr(fext)))) {
 	    f = n;
 	}
-	if (f == RSTRING_LEN(fname)) return fname;
+	if (f == RSTRING_LEN(fname)) return rb_str_new_shared(fname);
     }
     basename = rb_str_new(p, f);
     rb_enc_copy(basename, fname);
diff --git a/test/ruby/test_file_exhaustive.rb b/test/ruby/test_file_exhaustive.rb
index 420b3d527e..0a4d6d39f4 100644
--- a/test/ruby/test_file_exhaustive.rb
+++ b/test/ruby/test_file_exhaustive.rb
@@ -385,8 +385,10 @@ class TestFileExhaustive < Test::Unit::TestCase
 
   def test_basename
     assert_equal(File.basename(@file).sub(/\.test$/, ""), File.basename(@file, ".test"))
-    assert_equal("", File.basename(""))
-    assert_equal("foo", File.basename("foo"))
+    assert_equal("", s = File.basename(""))
+    assert(!s.frozen?, '[ruby-core:24199]')
+    assert_equal("foo", s = File.basename("foo"))
+    assert(!s.frozen?, '[ruby-core:24199]')
     assert_equal("foo", File.basename("foo", ".ext"))
     assert_equal("foo", File.basename("foo.ext", ".ext"))
     assert_equal("foo", File.basename("foo.ext", ".*"))
diff --git a/version.h b/version.h
index 6041a65e2d..cdcf83b57f 100644
--- a/version.h
+++ b/version.h
@@ -1,6 +1,6 @@
 #define RUBY_VERSION "1.9.1"
 #define RUBY_RELEASE_DATE "2009-07-12"
-#define RUBY_PATCHLEVEL 223
+#define RUBY_PATCHLEVEL 224
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 9
 #define RUBY_VERSION_TEENY 1