From dee853f23c65988d505796d11ac71c0fd2f8053e Mon Sep 17 00:00:00 2001
From: Eugen Rochko <eugen@zeonfederated.com>
Date: Fri, 24 Jan 2020 00:20:03 +0100
Subject: [PATCH] Remove bad encoding middleware (#12931)

Revert #12741
---
 .../handle_bad_encoding_middleware.rb         | 18 ----------------
 config/application.rb                         |  2 --
 .../handle_bad_encoding_middleware_spec.rb    | 21 -------------------
 3 files changed, 41 deletions(-)
 delete mode 100644 app/middleware/handle_bad_encoding_middleware.rb
 delete mode 100644 spec/middleware/handle_bad_encoding_middleware_spec.rb

diff --git a/app/middleware/handle_bad_encoding_middleware.rb b/app/middleware/handle_bad_encoding_middleware.rb
deleted file mode 100644
index 6fce84b152..0000000000
--- a/app/middleware/handle_bad_encoding_middleware.rb
+++ /dev/null
@@ -1,18 +0,0 @@
-# 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
diff --git a/config/application.rb b/config/application.rb
index c1bc18a303..bf25fa0d9e 100644
--- a/config/application.rb
+++ b/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
 
diff --git a/spec/middleware/handle_bad_encoding_middleware_spec.rb b/spec/middleware/handle_bad_encoding_middleware_spec.rb
deleted file mode 100644
index 8c0d24f182..0000000000
--- a/spec/middleware/handle_bad_encoding_middleware_spec.rb
+++ /dev/null
@@ -1,21 +0,0 @@
-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