Add show_dir_listing option for serve command

lib/jekyll/commands/serve.rb

@@ -10,6 +10,8 @@ module Jekyll
           "ssl_key"  => ["--ssl-key [KEY]", "X.509 (SSL) Private Key."],
           "port"     => ["-P", "--port [PORT]", "Port to listen on"],
           "baseurl"  => ["-b", "--baseurl [URL]", "Base URL"],
+          "show_dir_listing" => ["--show-dir-listing",
+            "Show a directory listing instead of loading your index file."],
           "skip_initial_build" => ["skip_initial_build", "--skip-initial-build",
             "Skips the initial site build which occurs before the server is started."]
         }
@@ -91,6 +93,8 @@ module Jekyll
             )
           }
 
+          opts[:DirectoryIndex] = [] if opts[:JekyllOptions]['show_dir_listing']
+
           enable_ssl(opts)
           enable_logging(opts)
           opts

lib/jekyll/configuration.rb

@@ -44,6 +44,7 @@ module Jekyll
       'port'          => '4000',
       'host'          => '127.0.0.1',
       'baseurl'       => '',
+      'show_dir_listing' => false,
 
       # Output Configuration
       'permalink'     => 'date',

test/test_commands_serve.rb

@@ -68,6 +68,11 @@ class TestCommandsServe < JekyllUnitTest
         ]
       end
 
+      should "use empty directory index list when show_dir_listing is true" do
+        opts = { "show_dir_listing" => true }
+        assert custom_opts(opts)[:DirectoryIndex].empty?
+      end
+
       context "verbose" do
         should "debug when verbose" do
           assert_equal custom_opts({ "verbose" => true })[:Logger].level, 5