[chore] Remove unnecessary/unused ErrorApp logic

- Removes logic for Ruby < 1.9
- Removes deprecated accept_html alias
- Remove backward compatibility support for Rack versions < 2.2

Author: chadlwilson

src/main/ruby/jruby/rack/error_app.rb

@@ -46,7 +46,7 @@ def call(env)
 
         code = response_code(env)
 
-        return respond(code) if ! root || ! accept_html?(env)
+        return respond(code) if !root || !accepts_html?(env)
 
         # TODO support custom JSON/XML 5xx and better HTTP_ACCEPT matching
         # NOTE: code == 503 ... we're try 503.html and fallback to 500.html
@@ -152,41 +152,9 @@ def expand_path(path, root = self.root)
         end
       end
 
-      begin
-        require 'rack/utils'
-        Utils = ::Rack::Utils
-
-        if ''.respond_to?(:bytesize) # Ruby >= 1.9
-          def Utils.bytesize(string); string.bytesize end
-        else
-          def Utils.bytesize(string); string.size end
-        end unless defined? Utils.bytesize
-
-        require 'rack/mime'
-      rescue LoadError; end
-
-      if defined? Utils.best_q_match
-
-        def accepts_html?(env)
-          Utils.best_q_match(env['HTTP_ACCEPT'], %w[text/html])
-        rescue
-          http_accept?(env, 'text/html')
-        end
-
-      else
-
-        def accepts_html?(env)
-          http_accept?(env, 'text/html') || http_accept?(env, '*/*')
-        end
-
+      def accepts_html?(env)
+        ::Rack::Utils.best_q_match(env['HTTP_ACCEPT'], %w[text/html])
       end
-      alias accept_html? accepts_html? # JRuby-Rack 1.1 compatibility
-
-      def http_accept?(env, mime)
-        http_accept = env['HTTP_ACCEPT'].to_s
-        http_accept.empty? ? nil : !! http_accept.index(mime)
-      end
-
     end
   end
 end

src/main/ruby/jruby/rack/error_app/show_status.rb

@@ -15,15 +15,15 @@ def initialize(app)
 
     def call(env)
       status, headers, body = @app.call(env)
-      headers = Utils::HeaderHash.new(headers)
+      headers = ::Rack::Utils::HeaderHash.new(headers)
       empty = headers['Content-Length'].to_i <= 0
 
       detail = env['rack.showstatus.detail']
       # client or server error, or explicit message
       if (status.to_i >= 400 && empty) || detail
         # required erb template variables (captured with binding) :
         request = req = ::Rack::Request.new(env); request && req # avoid un-used warning
-        message = Utils::HTTP_STATUS_CODES[status.to_i] || status.to_s
+        message = ::Rack::Utils::HTTP_STATUS_CODES[status.to_i] || status.to_s
         detail = detail.nil? ? message : detail # false for no detail
 
         body = @template.result(binding)
@@ -36,7 +36,7 @@ def call(env)
 
     # @private
     def h(obj)
-      obj.is_a?(String) ? Utils.escape_html(obj) : Utils.escape_html(obj.inspect)
+      obj.is_a?(String) ? ::Rack::Utils.escape_html(obj) : ::Rack::Utils.escape_html(obj.inspect)
     end
 
     # :stopdoc: