Merge branch 'master' into laurocaetano-fix_send_file

* master: (536 commits)
  doc, API example on how to use `Model#exists?` with multiple IDs. [ci skip]
  Restore DATABASE_URL even if it's nil in connection_handler test
  [ci skip] - error_messages_for has been deprecated since 2.3.8 - lets reduce any confusion for users
  Ensure Active Record connection consistency
  Revert "ask the fixture set for the sql statements"
  Check `respond_to` before delegation due to: https://github.com/ruby/ruby/commit/d781caaf313b8649948c107bba277e5ad7307314
  Adding Hash#compact and Hash#compact! methods
  MySQL version 4.1 was EOL on December 31, 2009 We should at least recommend modern versions of MySQL to users.
  clear cache on body close so that cache remains during rendering
  add a more restricted codepath for templates fixes #13390
  refactor generator tests to use block form of Tempfile
  Fix typo [ci skip]
  Move finish_template as the last public method in the generator
  Minor typos fix [ci skip]
  make `change_column_null` reversible. Closes #13576.
  create/drop test and development databases only if RAILS_ENV is nil
  Revert "Speedup String#to"
  typo fix in test name. [ci skip].
  `core_ext/string/access.rb` test what we are documenting.
  Fix typo in image_tag documentation
  ...

Conflicts:
	actionpack/CHANGELOG.md

22 files changed, 170 insertions, 98 deletions

diff --git a/actionpack/lib/action_dispatch/http/mime_negotiation.rb b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
index 40bb060d52..c33ba201e1 100644
--- a/actionpack/lib/action_dispatch/http/mime_negotiation.rb
+++ b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
@@ -10,6 +10,8 @@ module ActionDispatch
         self.ignore_accept_header = false
       end
 
+      attr_reader :variant
+
       # The MIME type of the HTTP request, such as Mime::XML.
       #
       # For backward compatibility, the post \format is extracted from the
@@ -48,7 +50,7 @@ module ActionDispatch
       #   GET /posts/5       | request.format => Mime::HTML or MIME::JS, or request.accepts.first
       #
       def format(view_path = [])
-        formats.first
+        formats.first || Mime::NullType.instance
       end
 
       def formats
@@ -64,6 +66,18 @@ module ActionDispatch
           end
       end
 
+      # Sets the \variant for template.
+      def variant=(variant)
+        if variant.is_a? Symbol
+          @variant = variant
+        else
+          raise ArgumentError, "request.variant must be set to a Symbol, not a #{variant.class}. " \
+            "For security reasons, never directly set the variant to a user-provided value, " \
+            "like params[:variant].to_sym. Check user-provided value against a whitelist first, " \
+            "then set the variant: request.variant = :tablet if params[:variant] == 'tablet'"
+        end
+      end
+
       # Sets the \format by string extension, which can be used to force custom formats
       # that are not controlled by the extension.
       #
diff --git a/actionpack/lib/action_dispatch/http/mime_type.rb b/actionpack/lib/action_dispatch/http/mime_type.rb
index ef144c3c76..3d2dd2d632 100644
--- a/actionpack/lib/action_dispatch/http/mime_type.rb
+++ b/actionpack/lib/action_dispatch/http/mime_type.rb
@@ -1,5 +1,6 @@
 require 'set'
-require 'active_support/core_ext/class/attribute_accessors'
+require 'singleton'
+require 'active_support/core_ext/module/attribute_accessors'
 require 'active_support/core_ext/string/starts_ends_with'
 
 module Mime
@@ -27,7 +28,7 @@ module Mime
   class << self
     def [](type)
       return type if type.is_a?(Type)
-      Type.lookup_by_extension(type) || NullType.new
+      Type.lookup_by_extension(type)
     end
 
     def fetch(type)
@@ -292,13 +293,13 @@ module Mime
   end
 
   class NullType
+    include Singleton
+
     def nil?
       true
     end
 
-    def ref
-      nil
-    end
+    def ref; end
 
     def respond_to_missing?(method, include_private = false)
       method.to_s.ends_with? '?'
diff --git a/actionpack/lib/action_dispatch/http/mime_types.rb b/actionpack/lib/action_dispatch/http/mime_types.rb
index a6b3aee5e7..0e4da36038 100644
--- a/actionpack/lib/action_dispatch/http/mime_types.rb
+++ b/actionpack/lib/action_dispatch/http/mime_types.rb
@@ -7,6 +7,7 @@ Mime::Type.register "text/javascript", :js, %w( application/javascript applicati
 Mime::Type.register "text/css", :css
 Mime::Type.register "text/calendar", :ics
 Mime::Type.register "text/csv", :csv
+Mime::Type.register "text/vcard", :vcf
 
 Mime::Type.register "image/png", :png, [], %w(png)
 Mime::Type.register "image/jpeg", :jpeg, [], %w(jpg jpeg jpe pjpeg)
diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 99b81c898f..1318c62fbe 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -271,7 +271,7 @@ module ActionDispatch
 
     # Override Rack's GET method to support indifferent access
     def GET
-      @env["action_dispatch.request.query_parameters"] ||= (normalize_encode_params(super) || {})
+      @env["action_dispatch.request.query_parameters"] ||= Utils.deep_munge((normalize_encode_params(super) || {}))
     rescue TypeError => e
       raise ActionController::BadRequest.new(:query, e)
     end
@@ -279,7 +279,7 @@ module ActionDispatch
 
     # Override Rack's POST method to support indifferent access
     def POST
-      @env["action_dispatch.request.request_parameters"] ||= (normalize_encode_params(super) || {})
+      @env["action_dispatch.request.request_parameters"] ||= Utils.deep_munge((normalize_encode_params(super) || {}))
     rescue TypeError => e
       raise ActionController::BadRequest.new(:request, e)
     end
diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index 5247e61a23..7b2655b2d8 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -1,4 +1,4 @@
-require 'active_support/core_ext/class/attribute_accessors'
+require 'active_support/core_ext/module/attribute_accessors'
 require 'monitor'
 
 module ActionDispatch # :nodoc:
diff --git a/actionpack/lib/action_dispatch/journey/formatter.rb b/actionpack/lib/action_dispatch/journey/formatter.rb
index 7764763791..4410c1b5d5 100644
--- a/actionpack/lib/action_dispatch/journey/formatter.rb
+++ b/actionpack/lib/action_dispatch/journey/formatter.rb
@@ -33,8 +33,8 @@ module ActionDispatch
           return [route.format(parameterized_parts), params]
         end
 
-        message = "No route matches #{constraints.inspect}"
-        message << " missing required keys: #{missing_keys.inspect}" if name
+        message = "No route matches #{Hash[constraints.sort].inspect}"
+        message << " missing required keys: #{missing_keys.sort.inspect}" if name
 
         raise ActionController::UrlGenerationError, message
       end
diff --git a/actionpack/lib/action_dispatch/journey/parser.rb b/actionpack/lib/action_dispatch/journey/parser.rb
index bb4cbb00e2..430812fafe 100644
--- a/actionpack/lib/action_dispatch/journey/parser.rb
+++ b/actionpack/lib/action_dispatch/journey/parser.rb
@@ -1,7 +1,7 @@
 #
 # DO NOT MODIFY!!!!
 # This file is automatically generated by Racc 1.4.9
-# from Racc grammer file "".
+# from Racc grammar file "".
 #
 
 require 'racc/parser.rb'
diff --git a/actionpack/lib/action_dispatch/journey/visitors.rb b/actionpack/lib/action_dispatch/journey/visitors.rb
index 9e66cab052..daade5bb74 100644
--- a/actionpack/lib/action_dispatch/journey/visitors.rb
+++ b/actionpack/lib/action_dispatch/journey/visitors.rb
@@ -77,12 +77,32 @@ module ActionDispatch
         end
       end
 
-      class OptimizedPath < String # :nodoc:
+      class OptimizedPath < Visitor # :nodoc:
+        def accept(node)
+          Array(visit(node))
+        end
+
         private
 
-        def visit_GROUP(node)
-          ""
-        end
+          def visit_CAT(node)
+            [visit(node.left), visit(node.right)].flatten
+          end
+
+          def visit_SYMBOL(node)
+            node.left[1..-1].to_sym
+          end
+
+          def visit_STAR(node)
+            visit(node.left)
+          end
+
+          def visit_GROUP(node)
+            []
+          end
+
+          %w{ LITERAL SLASH DOT }.each do |t|
+            class_eval %{ def visit_#{t}(n); n.left; end }, __FILE__, __LINE__
+          end
       end
 
       # Used for formatting urls (url_for)
diff --git a/actionpack/lib/action_dispatch/middleware/cookies.rb b/actionpack/lib/action_dispatch/middleware/cookies.rb
index 3ccd0c9ee8..fe110d7938 100644
--- a/actionpack/lib/action_dispatch/middleware/cookies.rb
+++ b/actionpack/lib/action_dispatch/middleware/cookies.rb
@@ -30,7 +30,7 @@ module ActionDispatch
   #   cookies[:login] = { value: "XJ-122", expires: 1.hour.from_now }
   #
   #   # Sets a signed cookie, which prevents users from tampering with its value.
-  #   # The cookie is signed by your app's <tt>config.secret_key_base</tt> value.
+  #   # The cookie is signed by your app's <tt>secrets.secret_key_base</tt> value.
   #   # It can be read using the signed method <tt>cookies.signed[:name]</tt>
   #   cookies.signed[:user_id] = current_user.id
   #
@@ -117,10 +117,10 @@ module ActionDispatch
       # the cookie again. This is useful for creating cookies with values that the user is not supposed to change. If a signed
       # cookie was tampered with by the user (or a 3rd party), nil will be returned.
       #
-      # If +config.secret_key_base+ and +config.secret_token+ (deprecated) are both set,
+      # If +secrets.secret_key_base+ and +config.secret_token+ (deprecated) are both set,
       # legacy cookies signed with the old key generator will be transparently upgraded.
       #
-      # This jar requires that you set a suitable secret for the verification on your app's +config.secret_key_base+.
+      # This jar requires that you set a suitable secret for the verification on your app's +secrets.secret_key_base+.
       #
       # Example:
       #
@@ -140,10 +140,10 @@ module ActionDispatch
       # Returns a jar that'll automatically encrypt cookie values before sending them to the client and will decrypt them for read.
       # If the cookie was tampered with by the user (or a 3rd party), nil will be returned.
       #
-      # If +config.secret_key_base+ and +config.secret_token+ (deprecated) are both set,
+      # If +secrets.secret_key_base+ and +config.secret_token+ (deprecated) are both set,
       # legacy cookies signed with the old key generator will be transparently upgraded.
       #
-      # This jar requires that you set a suitable secret for the verification on your app's +config.secret_key_base+.
+      # This jar requires that you set a suitable secret for the verification on your app's +secrets.secret_key_base+.
       #
       # Example:
       #
@@ -409,7 +409,7 @@ module ActionDispatch
     end
 
     # UpgradeLegacySignedCookieJar is used instead of SignedCookieJar if
-    # config.secret_token and config.secret_key_base are both set. It reads
+    # config.secret_token and secrets.secret_key_base are both set. It reads
     # legacy cookies signed with the old dummy key generator and re-saves
     # them using the new key generator to provide a smooth upgrade path.
     class UpgradeLegacySignedCookieJar < SignedCookieJar #:nodoc:
@@ -427,7 +427,7 @@ module ActionDispatch
 
       def initialize(parent_jar, key_generator, options = {})
         if ActiveSupport::LegacyKeyGenerator === key_generator
-          raise "You didn't set config.secret_key_base, which is required for this cookie jar. " +
+          raise "You didn't set secrets.secret_key_base, which is required for this cookie jar. " +
             "Read the upgrade documentation to learn more about this new config option."
         end
 
@@ -465,7 +465,7 @@ module ActionDispatch
     end
 
     # UpgradeLegacyEncryptedCookieJar is used by ActionDispatch::Session::CookieStore
-    # instead of EncryptedCookieJar if config.secret_token and config.secret_key_base
+    # instead of EncryptedCookieJar if config.secret_token and secrets.secret_key_base
     # are both set. It reads legacy cookies signed with the old dummy key generator and
     # encrypts and re-saves them using the new key generator to provide a smooth upgrade path.
     class UpgradeLegacyEncryptedCookieJar < EncryptedCookieJar #:nodoc:
diff --git a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
index 37bf9c8c9f..377f05c982 100644
--- a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
+++ b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
@@ -1,5 +1,5 @@
 require 'action_controller/metal/exceptions'
-require 'active_support/core_ext/class/attribute_accessors'
+require 'active_support/core_ext/module/attribute_accessors'
 
 module ActionDispatch
   class ExceptionWrapper
diff --git a/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb b/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
index b9eb8036e9..1ebc189c28 100644
--- a/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
+++ b/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
@@ -15,8 +15,8 @@ module ActionDispatch
     # best possible option given your application's configuration.
     #
     # If you only have secret_token set, your cookies will be signed, but
-    # not encrypted. This means a user cannot alter his +user_id+ without
-    # knowing your app's secret key, but can easily read his +user_id+. This
+    # not encrypted. This means a user cannot alter their +user_id+ without
+    # knowing your app's secret key, but can easily read their +user_id+. This
     # was the default for Rails 3 apps.
     #
     # If you have secret_key_base set, your cookies will be encrypted. This
@@ -31,9 +31,10 @@ module ActionDispatch
     #
     #   Myapp::Application.config.session_store :cookie_store, key: '_your_app_session'
     #
-    # Configure your secret key in config/initializers/secret_token.rb:
+    # Configure your secret key in config/secrets.yml:
     #
-    #   Myapp::Application.config.secret_key_base 'secret key'
+    #   development:
+    #     secret_key_base: 'secret key'
     #
     # To generate a secret key for an existing application, run `rake secret`.
     #
diff --git a/actionpack/lib/action_dispatch/middleware/static.rb b/actionpack/lib/action_dispatch/middleware/static.rb
index c6a7d9c415..2764584fe9 100644
--- a/actionpack/lib/action_dispatch/middleware/static.rb
+++ b/actionpack/lib/action_dispatch/middleware/static.rb
@@ -11,9 +11,10 @@ module ActionDispatch
     end
 
     def match?(path)
-      path = path.dup
+      path = unescape_path(path)
+      return false unless path.valid_encoding?
 
-      full_path = path.empty? ? @root : File.join(@root, escape_glob_chars(unescape_path(path)))
+      full_path = path.empty? ? @root : File.join(@root, escape_glob_chars(path))
       paths = "#{full_path}#{ext}"
 
       matches = Dir[paths]
@@ -40,7 +41,6 @@ module ActionDispatch
     end
 
     def escape_glob_chars(path)
-      path.force_encoding('binary') if path.respond_to? :force_encoding
       path.gsub(/[*?{}\[\]]/, "\\\\\\&")
     end
   end
diff --git a/actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb b/actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb
index 95461fa693..323873ba4b 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/routes/_table.html.erb
@@ -89,8 +89,8 @@
   }
 
   // takes an array of elements with a data-regexp attribute and
-  // passes their their parent <tr> into the callback function
-  // if the regexp matchs a given path
+  // passes their parent <tr> into the callback function
+  // if the regexp matches a given path
   function eachElemsForPath(elems, path, func) {
     each(elems, function(e){
       var reg = e.getAttribute("data-regexp");
diff --git a/actionpack/lib/action_dispatch/railtie.rb b/actionpack/lib/action_dispatch/railtie.rb
index 2dfaab3587..ddeea24bb3 100644
--- a/actionpack/lib/action_dispatch/railtie.rb
+++ b/actionpack/lib/action_dispatch/railtie.rb
@@ -16,6 +16,7 @@ module ActionDispatch
     config.action_dispatch.signed_cookie_salt = 'signed cookie'
     config.action_dispatch.encrypted_cookie_salt = 'encrypted cookie'
     config.action_dispatch.encrypted_signed_cookie_salt = 'signed encrypted cookie'
+    config.action_dispatch.perform_deep_munge = true
 
     config.action_dispatch.default_headers = {
       'X-Frame-Options' => 'SAMEORIGIN',
@@ -28,6 +29,7 @@ module ActionDispatch
     initializer "action_dispatch.configure" do |app|
       ActionDispatch::Http::URL.tld_length = app.config.action_dispatch.tld_length
       ActionDispatch::Request.ignore_accept_header = app.config.action_dispatch.ignore_accept_header
+      ActionDispatch::Request::Utils.perform_deep_munge = app.config.action_dispatch.perform_deep_munge
       ActionDispatch::Response.default_charset = app.config.action_dispatch.default_charset || app.config.encoding
       ActionDispatch::Response.default_headers = app.config.action_dispatch.default_headers
 
diff --git a/actionpack/lib/action_dispatch/request/session.rb b/actionpack/lib/action_dispatch/request/session.rb
index 6d911a75f1..973627f106 100644
--- a/actionpack/lib/action_dispatch/request/session.rb
+++ b/actionpack/lib/action_dispatch/request/session.rb
@@ -7,6 +7,9 @@ module ActionDispatch
       ENV_SESSION_KEY         = Rack::Session::Abstract::ENV_SESSION_KEY # :nodoc:
       ENV_SESSION_OPTIONS_KEY = Rack::Session::Abstract::ENV_SESSION_OPTIONS_KEY # :nodoc:
 
+      # Singleton object used to determine if an optional param wasn't specified
+      Unspecified = Object.new
+
       def self.create(store, env, default_options)
         session_was = find env
         session     = Request::Session.new(store, env)
@@ -127,15 +130,12 @@ module ActionDispatch
         @delegate.delete key.to_s
       end
 
-      def fetch(key, default=nil)
-        if self.key?(key)
-          self[key]
-        elsif default
-          self[key] = default
-        elsif block_given?
-          self[key] = yield(key)
+      def fetch(key, default=Unspecified, &block)
+        load_for_read!
+        if default == Unspecified
+          @delegate.fetch(key.to_s, &block)
         else
-          raise KeyError
+          @delegate.fetch(key.to_s, default, &block)
         end
       end
 
diff --git a/actionpack/lib/action_dispatch/request/utils.rb b/actionpack/lib/action_dispatch/request/utils.rb
index 8b43cdada8..a6dca9741c 100644
--- a/actionpack/lib/action_dispatch/request/utils.rb
+++ b/actionpack/lib/action_dispatch/request/utils.rb
@@ -1,9 +1,15 @@
 module ActionDispatch
   class Request < Rack::Request
     class Utils # :nodoc:
+
+      mattr_accessor :perform_deep_munge
+      self.perform_deep_munge = true
+
       class << self
         # Remove nils from the params hash
         def deep_munge(hash)
+          return hash unless perform_deep_munge
+
           hash.each do |k, v|
             case v
             when Array
diff --git a/actionpack/lib/action_dispatch/routing/inspector.rb b/actionpack/lib/action_dispatch/routing/inspector.rb
index 120bc54333..f612e91aef 100644
--- a/actionpack/lib/action_dispatch/routing/inspector.rb
+++ b/actionpack/lib/action_dispatch/routing/inspector.rb
@@ -69,7 +69,7 @@ module ActionDispatch
       end
 
       def internal?
-        controller.to_s =~ %r{\Arails/(info|welcome)} || path =~ %r{\A#{Rails.application.config.assets.prefix}}
+        controller.to_s =~ %r{\Arails/(info|mailers|welcome)} || path =~ %r{\A#{Rails.application.config.assets.prefix}\z}
       end
 
       def engine?
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 846a6345cb..18f37dc732 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -3,6 +3,7 @@ require 'active_support/core_ext/hash/reverse_merge'
 require 'active_support/core_ext/hash/slice'
 require 'active_support/core_ext/enumerable'
 require 'active_support/core_ext/array/extract_options'
+require 'active_support/core_ext/module/remove_method'
 require 'active_support/inflector'
 require 'action_dispatch/routing/redirection'
 
@@ -217,8 +218,12 @@ module ActionDispatch
               controller ||= default_controller
               action     ||= default_action
 
-              unless controller.is_a?(Regexp)
-                controller = [@scope[:module], controller].compact.join("/").presence
+              if @scope[:module] && !controller.is_a?(Regexp)
+                if controller =~ %r{\A/}
+                  controller = controller[1..-1]
+                else
+                  controller = [@scope[:module], controller].compact.join("/").presence
+                end
               end
 
               if controller.is_a?(String) && controller =~ %r{\A/}
@@ -502,11 +507,12 @@ module ActionDispatch
           raise "A rack application must be specified" unless path
 
           options[:as]  ||= app_name(app)
+          target_as       = name_for_action(options[:as], path)
           options[:via] ||= :all
 
           match(path, options.merge(:to => app, :anchor => false, :format => false))
 
-          define_generate_prefix(app, options[:as])
+          define_generate_prefix(app, target_as)
           self
         end
 
@@ -545,11 +551,11 @@ module ActionDispatch
             _routes = @set
             app.routes.define_mounted_helper(name)
             app.routes.singleton_class.class_eval do
-              define_method :mounted? do
+              redefine_method :mounted? do
                 true
               end
 
-              define_method :_generate_prefix do |options|
+              redefine_method :_generate_prefix do |options|
                 prefix_options = options.slice(*_route.segment_keys)
                 # we must actually delete prefix segment keys to avoid passing them to next url_for
                 _route.segment_keys.each { |k| options.delete(k) }
diff --git a/actionpack/lib/action_dispatch/routing/redirection.rb b/actionpack/lib/action_dispatch/routing/redirection.rb
index 3e54c7e71c..b08e62543b 100644
--- a/actionpack/lib/action_dispatch/routing/redirection.rb
+++ b/actionpack/lib/action_dispatch/routing/redirection.rb
@@ -26,14 +26,19 @@ module ActionDispatch
         end
 
         uri = URI.parse(path(req.symbolized_path_parameters, req))
+        
+        unless uri.host
+          if relative_path?(uri.path)
+            uri.path = "#{req.script_name}/#{uri.path}"
+          elsif uri.path.empty?
+            uri.path = req.script_name.empty? ? "/" : req.script_name
+          end
+        end
+          
         uri.scheme ||= req.scheme
         uri.host   ||= req.host
         uri.port   ||= req.port unless req.standard_port?
 
-        if relative_path?(uri.path)
-          uri.path = "#{req.script_name}/#{uri.path}"
-        end
-
         body = %(<html><body>You are being <a href="#{ERB::Util.h(uri.to_s)}">redirected</a>.</body></html>)
 
         headers = {
@@ -57,11 +62,33 @@ module ActionDispatch
         def relative_path?(path)
           path && !path.empty? && path[0] != '/'
         end
+
+        def escape(params)
+          Hash[params.map{ |k,v| [k, Rack::Utils.escape(v)] }]
+        end
+
+        def escape_fragment(params)
+          Hash[params.map{ |k,v| [k, Journey::Router::Utils.escape_fragment(v)] }]
+        end
+
+        def escape_path(params)
+          Hash[params.map{ |k,v| [k, Journey::Router::Utils.escape_path(v)] }]
+        end
     end
 
     class PathRedirect < Redirect
+      URL_PARTS = /\A([^?]+)?(\?[^#]+)?(#.+)?\z/
+
       def path(params, request)
-        (params.empty? || !block.match(/%\{\w*\}/)) ? block : (block % escape(params))
+        if block.match(URL_PARTS)
+          path     = interpolation_required?($1, params) ? $1 % escape_path(params)     : $1
+          query    = interpolation_required?($2, params) ? $2 % escape(params)          : $2
+          fragment = interpolation_required?($3, params) ? $3 % escape_fragment(params) : $3
+
+          "#{path}#{query}#{fragment}"
+        else
+          interpolation_required?(block, params) ? block % escape(params) : block
+        end
       end
 
       def inspect
@@ -69,8 +96,8 @@ module ActionDispatch
       end
 
       private
-        def escape(params)
-          Hash[params.map{ |k,v| [k, Rack::Utils.escape(v)] }]
+        def interpolation_required?(string, params)
+          !params.empty? && string && string.match(/%\{\w*\}/)
         end
     end
 
@@ -90,22 +117,22 @@ module ActionDispatch
           url_options[:path] = (url_options[:path] % escape_path(params))
         end
 
-        if relative_path?(url_options[:path])
-          url_options[:path] = "/#{url_options[:path]}"
-          url_options[:script_name] = request.script_name
+        unless options[:host] || options[:domain]
+          if relative_path?(url_options[:path])
+            url_options[:path] = "/#{url_options[:path]}"
+            url_options[:script_name] = request.script_name
+          elsif url_options[:path].empty?
+            url_options[:path] = request.script_name.empty? ? "/" : ""
+            url_options[:script_name] = request.script_name
+          end
         end
-
+        
         ActionDispatch::Http::URL.url_for url_options
       end
 
       def inspect
         "redirect(#{status}, #{options.map{ |k,v| "#{k}: #{v}" }.join(', ')})"
       end
-
-      private
-        def escape_path(params)
-          Hash[params.map{ |k,v| [k, URI.parser.escape(v)] }]
-        end
     end
 
     module Redirection
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index b8abdabca5..a03fb4cee7 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -163,9 +163,10 @@ module ActionDispatch
 
             def initialize(route, options)
               super
-              @path_parts   = @route.required_parts
-              @arg_size     = @path_parts.size
-              @string_route = @route.optimized_path
+              @klass          = Journey::Router::Utils
+              @required_parts = @route.required_parts
+              @arg_size       = @required_parts.size
+              @optimized_path = @route.optimized_path
             end
 
             def call(t, args)
@@ -182,43 +183,36 @@ module ActionDispatch
             private
 
             def optimized_helper(args)
-              path = @string_route.dup
-              klass = Journey::Router::Utils
+              params = Hash[parameterize_args(args)]
+              missing_keys = missing_keys(params)
 
-              @path_parts.zip(args) do |part, arg|
-                parameterized_arg = arg.to_param
+              unless missing_keys.empty?
+                raise_generation_error(params, missing_keys)
+              end
 
-                if parameterized_arg.nil? || parameterized_arg.empty?
-                  raise_generation_error(args)
-                end
+              @optimized_path.map{ |segment| replace_segment(params, segment) }.join
+            end
 
-                # Replace each route parameter
-                # e.g. :id for regular parameter or *path for globbing
-                # with ruby string interpolation code
-                path.gsub!(/(\*|:)#{part}/, klass.escape_fragment(parameterized_arg))
-              end
-              path
+            def replace_segment(params, segment)
+              Symbol === segment ? @klass.escape_fragment(params[segment]) : segment
             end
 
             def optimize_routes_generation?(t)
               t.send(:optimize_routes_generation?)
             end
 
-            def raise_generation_error(args)
-              parts, missing_keys = [], []
-
-              @path_parts.zip(args) do |part, arg|
-                parameterized_arg = arg.to_param
-
-                if parameterized_arg.nil? || parameterized_arg.empty?
-                  missing_keys << part
-                end
+            def parameterize_args(args)
+              @required_parts.zip(args.map(&:to_param))
+            end
 
-                parts << [part, arg]
-              end
+            def missing_keys(args)
+              args.select{ |part, arg| arg.nil? || arg.empty? }.keys
+            end
 
-              message = "No route matches #{Hash[parts].inspect}"
-              message << " missing required keys: #{missing_keys.inspect}"
+            def raise_generation_error(args, missing_keys)
+              constraints = Hash[@route.requirements.merge(args).sort]
+              message = "No route matches #{constraints.inspect}"
+              message << " missing required keys: #{missing_keys.sort.inspect}"
 
               raise ActionController::UrlGenerationError, message
             end
@@ -226,7 +220,7 @@ module ActionDispatch
 
           def initialize(route, options)
             @options      = options
-            @segment_keys = route.segment_keys
+            @segment_keys = route.segment_keys.uniq
             @route        = route
           end
 
@@ -361,7 +355,7 @@ module ActionDispatch
         include UrlFor
       end
 
-      # Contains all the mounted helpers accross different
+      # Contains all the mounted helpers across different
       # engines and the `main_app` helper for the application.
       # You can include this in your classes if you want to
       # access routes for other engines.
diff --git a/actionpack/lib/action_dispatch/testing/assertions/routing.rb b/actionpack/lib/action_dispatch/testing/assertions/routing.rb
index 496682e8bd..f1f998d932 100644
--- a/actionpack/lib/action_dispatch/testing/assertions/routing.rb
+++ b/actionpack/lib/action_dispatch/testing/assertions/routing.rb
@@ -211,7 +211,7 @@ module ActionDispatch
         def fail_on(exception_class)
           yield
         rescue exception_class => e
-          raise MiniTest::Assertion, e.message
+          raise Minitest::Assertion, e.message
         end
     end
   end
diff --git a/actionpack/lib/action_dispatch/testing/integration.rb b/actionpack/lib/action_dispatch/testing/integration.rb
index 9beb30307b..cc6b763093 100644
--- a/actionpack/lib/action_dispatch/testing/integration.rb
+++ b/actionpack/lib/action_dispatch/testing/integration.rb
@@ -137,7 +137,7 @@ module ActionDispatch
     class Session
       DEFAULT_HOST = "www.example.com"
 
-      include MiniTest::Assertions
+      include Minitest::Assertions
       include TestProcess, RequestHelpers, Assertions
 
       %w( status status_message headers body redirect? ).each do |method|
@@ -242,7 +242,7 @@ module ActionDispatch
         @https = flag
       end
 
-      # Return +true+ if the session is mimicking a secure HTTPS request.
+      # Returns +true+ if the session is mimicking a secure HTTPS request.
       #
       #   if session.https?
       #     ...