add a test: "y".count("a\\-z") should be 0.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@14827 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/ruby/test_string.rb

@@ -384,6 +384,7 @@ class TestString < Test::Unit::TestCase
     assert_equal(2, a.count(S("lo"), S("o")))
     assert_equal(4, a.count(S("hello"), S("^l")))
     assert_equal(4, a.count(S("ej-m")))
+    assert_equal(0, S("y").count(S("a\\-z")))
   end
 
   def test_crypt