Remove bad encoding middleware (#12931)

Revert #12741

app/middleware/handle_bad_encoding_middleware.rb

-# frozen_string_literal: true
-# See: https://jamescrisp.org/2018/05/28/fixing-invalid-query-parameters-invalid-encoding-in-a-rails-app/
-
-class HandleBadEncodingMiddleware
-  def initialize(app)
-    @app = app
-  end
-
-  def call(env)
-    begin
-      Rack::Utils.parse_nested_query(env['QUERY_STRING'].to_s)
-    rescue Rack::Utils::InvalidParameterError
-      env['QUERY_STRING'] = ''
-    end
-
-    @app.call(env)
-  end
-end

config/application.rb

@@ -7,7 +7,6 @@ require 'rails/all'
 Bundler.require(*Rails.groups)
 
 require_relative '../app/lib/exceptions'
-require_relative '../app/middleware/handle_bad_encoding_middleware'
 require_relative '../lib/paperclip/lazy_thumbnail'
 require_relative '../lib/paperclip/gif_transcoder'
 require_relative '../lib/paperclip/video_transcoder'
@@ -120,7 +119,6 @@ module Mastodon
 
     config.active_job.queue_adapter = :sidekiq
 
-    config.middleware.insert_before Rack::Runtime, HandleBadEncodingMiddleware
     config.middleware.use Rack::Attack
     config.middleware.use Rack::Deflater
 

spec/middleware/handle_bad_encoding_middleware_spec.rb

-require 'rails_helper'
-
-RSpec.describe HandleBadEncodingMiddleware do
-  let(:app) { double() }
-  let(:middleware) { HandleBadEncodingMiddleware.new(app) }
-
-  it "request with query string is unchanged" do
-    expect(app).to receive(:call).with("PATH" => "/some/path", "QUERY_STRING" => "name=fred")
-    middleware.call("PATH" => "/some/path", "QUERY_STRING" => "name=fred")
-  end
-
-  it "request with no query string is unchanged" do
-    expect(app).to receive(:call).with("PATH" => "/some/path")
-    middleware.call("PATH" => "/some/path")
-  end
-
-  it "request with invalid encoding in query string drops query string" do
-    expect(app).to receive(:call).with("QUERY_STRING" => "", "PATH" => "/some/path")
-    middleware.call("QUERY_STRING" => "q=%2Fsearch%2Fall%Forder%3Ddescending%26page%3D5%26sort%3Dcreated_at", "PATH" => "/some/path")
-  end
-end