Remove unused file_dir attribute

Similar to the class_dir attribute, the file_dir attribute never returns
anything but nil.

Author: st0012

lib/rdoc/code_object/top_level.rb

@@ -246,7 +246,7 @@ def page_name
   # Path to this file for use with HTML generator output.
 
   def path
-    http_url @store.rdoc.generator.file_dir
+    http_url(nil)
   end
 
   def pretty_print q # :nodoc:

lib/rdoc/generator/darkfish.rb

@@ -184,14 +184,6 @@ def debug_msg *msg
     $stderr.puts(*msg)
   end
 
-  ##
-  # Directory where generated class HTML files live relative to the output
-  # dir.
-
-  def file_dir
-    nil
-  end
-
   ##
   # Create the directories the generated docs will live in if they don't
   # already exist.

lib/rdoc/generator/json_index.rb

@@ -86,9 +86,7 @@ class RDoc::Generator::JsonIndex
   attr_reader :index # :nodoc:
 
   ##
-  # Creates a new generator.  +parent_generator+ is used to determine the
-  # file_dir of links in the output index.
-  #
+  # Creates a new generator.
   # +options+ are the same options passed to the parent generator.
 
   def initialize parent_generator, options
@@ -265,13 +263,6 @@ def index_pages
     end
   end
 
-  ##
-  # The directory files are written to
-
-  def file_dir
-    @parent_generator.file_dir
-  end
-
   def reset files, classes # :nodoc:
     @files   = files
     @classes = classes

test/rdoc/support/test_case.rb

@@ -53,9 +53,7 @@ def setup
     @rdoc.store = @store
     @rdoc.options = RDoc::Options.new
 
-    g = Object.new
-    def g.file_dir() end
-    @rdoc.generator = g
+    @rdoc.generator = Object.new
 
     RDoc::Markup::PreProcess.reset
   end

test/rdoc/test_rdoc_generator_json_index.rb

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

test/rdoc/xref_test_case.rb

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