Add tests for @a883e14

This was imported from trunk but no tests were added.  Now we have some
nice tests to prevent regeressions.

Fixes #270

Author: drbrain

test/test_rdoc_constant.rb

@@ -8,6 +8,36 @@ def setup
     @const = @c1.constants.first
   end
 
+  def test_documented_eh
+    top_level = @store.add_file 'file.rb'
+
+    const = RDoc::Constant.new 'CONST', nil, nil
+    top_level.add_constant const
+
+    refute const.documented?
+
+    const.comment = comment 'comment'
+
+    assert const.documented?
+  end
+
+  def test_documented_eh_alias
+    top_level = @store.add_file 'file.rb'
+
+    const = RDoc::Constant.new 'CONST', nil, nil
+    top_level.add_constant const
+
+    refute const.documented?
+
+    const.is_alias_for = 'C1'
+
+    refute const.documented?
+
+    @c1.add_comment comment('comment'), @top_level
+
+    assert const.documented?
+  end
+
   def test_full_name
     assert_equal 'C1::CONST', @const.full_name
   end