test/rdoc: skip some tests when euid is root

root user can access a file whose permission is 0000.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@66569 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/rdoc/test_rdoc_options.rb

@@ -18,6 +18,7 @@ class TestRDocOptions < RDoc::TestCase
 
   def test_check_files
     skip "assumes UNIX permission model" if /mswin|mingw/ =~ RUBY_PLATFORM
+    skip "assumes that euid is not root" if Process.euid == 0
 
     out, err = capture_io do
       temp_dir do

test/rdoc/test_rdoc_rdoc.rb

@@ -350,6 +350,7 @@ class TestRDocRDoc < RDoc::TestCase
 
   def test_parse_file_forbidden
     skip 'chmod not supported' if Gem.win_platform?
+    skip "assumes that euid is not root" if Process.euid == 0
 
     @rdoc.store = RDoc::Store.new
 

test/rdoc/test_rdoc_rubygems_hook.rb

@@ -200,6 +200,8 @@ class TestRDocRubygemsHook < Gem::TestCase
 
   def test_remove_unwritable
     skip 'chmod not supported' if Gem.win_platform?
+    skip "assumes that euid is not root" if Process.euid == 0
+
     FileUtils.mkdir_p @a.base_dir
     FileUtils.chmod 0, @a.base_dir
 
@@ -228,6 +230,8 @@ class TestRDocRubygemsHook < Gem::TestCase
 
   def test_setup_unwritable
     skip 'chmod not supported' if Gem.win_platform?
+    skip "assumes that euid is not root" if Process.euid == 0
+
     FileUtils.mkdir_p @a.doc_dir
     FileUtils.chmod 0, @a.doc_dir