[ruby/rdoc] Finalize RDoc::Options before calling

RDoc::RDoc#parse_files
(https://github.com/ruby/rdoc/pull/1274)

Commit https://github.com/ruby/rdoc/commit/6cf6e1647b97, which went to v6.5.0, changed `RDoc::Options#parse`
to not call `#finish` in it. While the commit adjusted other call sites,
it missed `lib/rdoc/rubygems_hook.rb`.

`RDoc::Options#finish` prepares the include paths for `:include:`
directives. This has to be done before starting to parse sources.

I think this should fix https://github.com/ruby/net-http/issues/193 +
https://github.com/ruby/net-http/pull/194.

https://github.com/ruby/rdoc/commit/d62da8ca09

lib/rdoc/rubygems_hook.rb

@@ -181,10 +181,10 @@ class RDoc::RubyGemsHook
       options = ::RDoc::Options.new
       options.default_title = "#{@spec.full_name} Documentation"
       options.parse args
+      options.quiet = !Gem.configuration.really_verbose
+      options.finish
     end
 
-    options.quiet = !Gem.configuration.really_verbose
-
     @rdoc = new_rdoc
     @rdoc.options = options
 

test/rdoc/test_rdoc_rubygems_hook.rb

@@ -37,8 +37,15 @@ class TestRDocRubyGemsHook < Test::Unit::TestCase
     @a.loaded_from = File.join(@tempdir, 'a-2', 'a-2.gemspec')
 
     FileUtils.mkdir_p File.join(@tempdir, 'a-2', 'lib')
-    FileUtils.touch   File.join(@tempdir, 'a-2', 'lib', 'a.rb')
     FileUtils.touch   File.join(@tempdir, 'a-2', 'README')
+    File.open(File.join(@tempdir, 'a-2', 'lib', 'a.rb'), 'w') do |f|
+      f.puts '# comment'
+      f.puts '# :include: include.txt'
+      f.puts 'class A; end'
+    end
+    File.open(File.join(@tempdir, 'a-2', 'include.txt'), 'w') do |f|
+      f.puts 'included content'
+    end
 
     @hook = RDoc::RubyGemsHook.new @a
 
@@ -112,6 +119,10 @@ class TestRDocRubyGemsHook < Test::Unit::TestCase
     assert_equal %w[README lib], rdoc.options.files.sort
 
     assert_equal 'MyTitle', rdoc.store.main
+
+    klass = rdoc.store.find_class_named('A')
+    refute_nil klass
+    assert_includes klass.comment.text, 'included content'
   end
 
   def test_generate_all