test_etc.rb: fix test_getgrnam for duplicated group names

* test/etc/test_etc.rb: Etc.getgrnam would not return the first entry in the order of Etc.group for duplicated group names.

follow-up: [Bug #6935]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60063 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

test/etc/test_etc.rb

@@ -97,12 +97,12 @@ class TestEtc < Test::Unit::TestCase
   end
 
   def test_getgrnam
-    groups = {}
+    groups = Hash.new {[]}
     Etc.group do |s|
-      groups[s.name] ||= s.gid unless /\A\+/ =~ s.name
+      groups[s.name] |= [s.gid] unless /\A\+/ =~ s.name
     end
     groups.each_pair do |n, s|
-      assert_equal(s, Etc.getgrnam(n).gid)
+      assert_include(s, Etc.getgrnam(n).gid)
     end
   end