fix file path for building at other than src dir.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@27163 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/rdoc/test_rdoc_rdoc.rb

@@ -15,8 +15,8 @@ class TestRDocRDoc < MiniTest::Unit::TestCase
   end
 
   def test_gather_files
-    assert_equal(%w[lib/rdoc.rb],
-                 @rdoc.gather_files(%w[lib/rdoc.rb lib/rdoc.rb]))
+    file = File.expand_path("../../../lib/rdoc.rb", __FILE__)
+    assert_equal([file], @rdoc.gather_files([file, file]))
   end
 
   def test_read_file_contents