diff --git a/ChangeLog b/ChangeLog
index e9d111b28b..8f3cf7533e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jul 27 10:24:50 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* lib/rdoc/parser.rb (RDoc::Parser.binary?): fix for empty files.
+	  [ruby-dev:38848]
+
 Sun Jul 26 19:17:33 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* io.c (argf_eof): go to the next file if called after ARGF.close
diff --git a/lib/rdoc/parser.rb b/lib/rdoc/parser.rb
index bb7e0c7d81..3798734d5e 100644
--- a/lib/rdoc/parser.rb
+++ b/lib/rdoc/parser.rb
@@ -66,8 +66,8 @@ class RDoc::Parser
   # Return _true_ if the +file+ seems like binary.
 
   def self.binary?(file)
-    s = File.read(file, 1024)
-    s.count("^ -~\t\r\n").fdiv(s.size) > 0.3 || s.index("\x00") unless s.empty?
+    s = File.read(file, 1024) or return false
+    s.count("^ -~\t\r\n").fdiv(s.size) > 0.3 || s.index("\x00")
   end
   private_class_method :binary?
 
diff --git a/test/rdoc/test_rdoc_parser.rb b/test/rdoc/test_rdoc_parser.rb
index d6420d20f1..19e859e528 100644
--- a/test/rdoc/test_rdoc_parser.rb
+++ b/test/rdoc/test_rdoc_parser.rb
@@ -1,9 +1,9 @@
 require 'rubygems'
-require 'minitest/unit'
+require 'test/unit'
 require 'rdoc/parser'
 require 'rdoc/parser/ruby'
 
-class TestRDocParser < MiniTest::Unit::TestCase
+class TestRDocParser < Test::Unit::TestCase
   def test_can_parse
     assert_equal(RDoc::Parser.can_parse(__FILE__), RDoc::Parser::Ruby)
 
@@ -16,7 +16,9 @@ class TestRDocParser < MiniTest::Unit::TestCase
     assert_equal(RDoc::Parser.can_parse(readme_file_name), RDoc::Parser::Simple)
 
     binary_file_name = File.join(File.dirname(__FILE__), "binary.dat")
-    assert_equal(RDoc::Parser.can_parse(binary_file_name), nil)
+    assert_nil(RDoc::Parser.can_parse(binary_file_name))
+    empty_file_name = File.join(File.dirname(__FILE__), "empty.dat")
+    assert_not_nil(RDoc::Parser.can_parse(empty_file_name))
   end
 end