Remove unused class_dir attribute

In all generators it only returns nil.

Author: st0012

lib/rdoc/code_object/class_module.rb

@@ -634,7 +634,7 @@ def parse comment_location
   # Path to this class or module for use with HTML generator output.
 
   def path
-    http_url @store.rdoc.generator.class_dir
+    http_url(nil)
   end
 
   ##

lib/rdoc/generator/darkfish.rb

@@ -188,14 +188,6 @@ def debug_msg *msg
   # Directory where generated class HTML files live relative to the output
   # dir.
 
-  def class_dir
-    nil
-  end
-
-  ##
-  # Directory where generated class HTML files live relative to the output
-  # dir.
-
   def file_dir
     nil
   end

lib/rdoc/generator/json_index.rb

@@ -87,7 +87,7 @@ class RDoc::Generator::JsonIndex
 
   ##
   # Creates a new generator.  +parent_generator+ is used to determine the
-  # class_dir and file_dir of links in the output index.
+  # file_dir of links in the output index.
   #
   # +options+ are the same options passed to the parent generator.
 
@@ -265,13 +265,6 @@ def index_pages
     end
   end
 
-  ##
-  # The directory classes are written to
-
-  def class_dir
-    @parent_generator.class_dir
-  end
-
   ##
   # The directory files are written to
 

lib/rdoc/generator/pot.rb

@@ -81,11 +81,6 @@ def generate
     end
   end
 
-  # :nodoc:
-  def class_dir
-    nil
-  end
-
   private
   def extract_messages
     extractor = MessageExtractor.new(@store)

test/rdoc/support/test_case.rb

@@ -54,7 +54,6 @@ def setup
     @rdoc.options = RDoc::Options.new
 
     g = Object.new
-    def g.class_dir() end
     def g.file_dir() end
     @rdoc.generator = g
 

test/rdoc/test_rdoc_generator_json_index.rb

@@ -80,10 +80,6 @@ def test_build_index
     assert_equal expected, index
   end
 
-  def test_class_dir
-    assert_equal @darkfish.class_dir, @g.class_dir
-  end
-
   def test_file_dir
     assert_equal @darkfish.file_dir, @g.file_dir
   end

test/rdoc/xref_test_case.rb

@@ -30,7 +30,6 @@ def setup
     @top_levels.push @example_md
 
     generator = Object.new
-    def generator.class_dir() nil end
     def generator.file_dir() nil end
     @rdoc.options = @options
     @rdoc.generator = generator