Add hash equality to Section

When an item is not in any section it ends up in the nil section.
Unfortunately RDoc creates a separate Section object between grouping
and display time which would cause items to disappear from a section at
HTML generation time.

Now that two Section objects with the same title map to the same Hash
key the constants will not disappear.

Fixes bug #399

History.rdoc

@@ -2,6 +2,8 @@
 
 * Bug fixes
   * Ensure badge data is included in result of JsonIndex template.
+  * Ensure items in the nil section are displayed in HTML output.  Issue #399
+    by Daniel Svensson.
 
 === 4.2.2 / 2016-02-09
 

lib/rdoc/context/section.rb

@@ -57,6 +57,8 @@ def == other
     self.class === other and @title == other.title
   end
 
+  alias eql? ==
+
   ##
   # Adds +comment+ to this section
 
@@ -127,6 +129,10 @@ def inspect # :nodoc:
     "#<%s:0x%x %p>" % [self.class, object_id, title]
   end
 
+  def hash # :nodoc:
+    @title.hash
+  end
+
   ##
   # The files comments in this section come from
 

test/test_rdoc_context_section.rb

@@ -47,6 +47,22 @@ def test_aref
     assert_equal 'one+two', @S.new(nil, 'one two', nil).aref
   end
 
+  def test_eql_eh
+    other = @S.new @klass, 'other', comment('# comment', @top_level)
+
+    assert @s.eql? @s
+    assert @s.eql? @s.dup
+    refute @s.eql? other
+  end
+
+  def test_equals
+    other = @S.new @klass, 'other', comment('# comment', @top_level)
+
+    assert_equal @s, @s
+    assert_equal @s, @s.dup
+    refute_equal @s, other
+  end
+
   def test_extract_comment
     assert_equal '',    @s.extract_comment(comment('')).text
     assert_equal '',    @s.extract_comment(comment("# :section: b\n")).text
@@ -55,6 +71,14 @@ def test_extract_comment
                  @s.extract_comment(comment("# a\n# :section: b\n# c")).text
   end
 
+  def test_hash
+    other = @S.new @klass, 'other', comment('# comment', @top_level)
+
+    assert_equal @s.hash, @s.hash
+    assert_equal @s.hash, @s.dup.hash
+    refute_equal @s.hash, other.hash
+  end
+
   def test_marshal_dump
     loaded = Marshal.load Marshal.dump @s