Merge branch 'master' into loofah

Conflicts:
	actionpack/CHANGELOG.md
	actionpack/test/controller/integration_test.rb
	actionview/CHANGELOG.md

24 files changed, 434 insertions, 307 deletions

diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 01f117be99..8c035c3c6c 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -23,7 +23,7 @@ module ActionDispatch
     autoload :Session, 'action_dispatch/request/session'
     autoload :Utils,   'action_dispatch/request/utils'
 
-    LOCALHOST   = Regexp.union [/^127\.0\.0\.\d{1,3}$/, /^::1$/, /^0:0:0:0:0:0:0:1(%.*)?$/]
+    LOCALHOST   = Regexp.union [/^127\.\d{1,3}\.\d{1,3}\.\d{1,3}$/, /^::1$/, /^0:0:0:0:0:0:0:1(%.*)?$/]
 
     ENV_METHODS = %w[ AUTH_TYPE GATEWAY_INTERFACE
         PATH_TRANSLATED REMOTE_HOST
@@ -225,7 +225,7 @@ module ActionDispatch
       @remote_ip ||= (@env["action_dispatch.remote_ip"] || ip).to_s
     end
 
-    # Returns the unique request id, which is based off either the X-Request-Id header that can
+    # Returns the unique request id, which is based on either the X-Request-Id header that can
     # be generated by a firewall, load balancer, or web server or by the RequestId middleware
     # (which sets the action_dispatch.request_id environment variable).
     #
diff --git a/actionpack/lib/action_dispatch/http/upload.rb b/actionpack/lib/action_dispatch/http/upload.rb
index 45bf751d09..540e11a4a0 100644
--- a/actionpack/lib/action_dispatch/http/upload.rb
+++ b/actionpack/lib/action_dispatch/http/upload.rb
@@ -27,7 +27,8 @@ module ActionDispatch
         @tempfile          = hash[:tempfile]
         raise(ArgumentError, ':tempfile is required') unless @tempfile
 
-        @original_filename = encode_filename(hash[:filename])
+        @original_filename = hash[:filename]
+        @original_filename &&= @original_filename.encode "UTF-8"
         @content_type      = hash[:type]
         @headers           = hash[:head]
       end
@@ -66,13 +67,6 @@ module ActionDispatch
       def eof?
         @tempfile.eof?
       end
-
-      private
-
-      def encode_filename(filename)
-        # Encode the filename in the utf8 encoding, unless it is nil
-        filename.force_encoding(Encoding::UTF_8).encode! if filename
-      end
     end
   end
 end
diff --git a/actionpack/lib/action_dispatch/http/url.rb b/actionpack/lib/action_dispatch/http/url.rb
index 6ba2820d09..6b8dcaf497 100644
--- a/actionpack/lib/action_dispatch/http/url.rb
+++ b/actionpack/lib/action_dispatch/http/url.rb
@@ -29,39 +29,48 @@ module ActionDispatch
         end
 
         def url_for(options)
-          host = options[:host]
-          unless host || options[:only_path]
-            raise ArgumentError, 'Missing host to link to! Please provide the :host parameter, set default_url_options[:host], or set :only_path to true'
+          if options[:only_path]
+            path_for options
+          else
+            full_url_for options
           end
+        end
 
-          path  = options[:script_name].to_s.chomp("/")
-          path << options[:path].to_s
+        def full_url_for(options)
+          host     = options[:host]
+          protocol = options[:protocol]
+          port     = options[:port]
 
-          path = add_trailing_slash(path) if options[:trailing_slash]
+          unless host
+            raise ArgumentError, 'Missing host to link to! Please provide the :host parameter, set default_url_options[:host], or set :only_path to true'
+          end
 
-          result = if options[:only_path]
-                     path
-                   else
-                     protocol = options[:protocol]
-                     port     = options[:port]
-                     build_host_url(host, port, protocol, options).concat path
-                   end
+          build_host_url(host, port, protocol, options, path_for(options))
+        end
 
-          if options.key? :params
-            params = options[:params].is_a?(Hash) ?
-                                 options[:params] :
-                                 { params: options[:params] }
+        def path_for(options)
+          path  = options[:script_name].to_s.chomp("/")
+          path << options[:path] if options.key?(:path)
 
-            params.reject! { |_,v| v.to_param.nil? }
-            result << "?#{params.to_query}" unless params.empty?
-          end
+          add_trailing_slash(path) if options[:trailing_slash]
+          add_params(path, options[:params]) if options.key?(:params)
+          add_anchor(path, options[:anchor]) if options.key?(:anchor)
 
-          result << "##{Journey::Router::Utils.escape_fragment(options[:anchor].to_param.to_s)}" if options[:anchor]
-          result
+          path
         end
 
         private
 
+        def add_params(path, params)
+          params = { params: params } unless params.is_a?(Hash)
+          params.reject! { |_,v| v.to_param.nil? }
+          path << "?#{params.to_query}" unless params.empty?
+        end
+
+        def add_anchor(path, anchor)
+          path << "##{Journey::Router::Utils.escape_fragment(anchor.to_param.to_s)}"
+        end
+
         def extract_domain_from(host, tld_length)
           host.split('.').last(1 + tld_length).join('.')
         end
@@ -79,19 +88,17 @@ module ActionDispatch
           elsif !path.include?(".")
             path.sub!(/[^\/]\z|\A\z/, '\&/')
           end
-
-          path
         end
 
-        def build_host_url(host, port, protocol, options)
+        def build_host_url(host, port, protocol, options, path)
           if match = host.match(HOST_REGEXP)
-            protocol           ||= match[1] unless protocol == false
-            host                 = match[2]
-            port                 = match[3] unless options.key? :port
+            protocol ||= match[1] unless protocol == false
+            host       = match[2]
+            port       = match[3] unless options.key? :port
           end
 
-          protocol       = normalize_protocol protocol
-          host           = normalize_host(host, options)
+          protocol = normalize_protocol protocol
+          host     = normalize_host(host, options)
 
           result = protocol.dup
 
@@ -104,7 +111,7 @@ module ActionDispatch
             result << ":#{normalized_port}"
           }
 
-          result
+          result.concat path
         end
 
         def named_host?(host)
diff --git a/actionpack/lib/action_dispatch/journey/formatter.rb b/actionpack/lib/action_dispatch/journey/formatter.rb
index 6d58323789..59b353b1b7 100644
--- a/actionpack/lib/action_dispatch/journey/formatter.rb
+++ b/actionpack/lib/action_dispatch/journey/formatter.rb
@@ -12,12 +12,12 @@ module ActionDispatch
         @cache  = nil
       end
 
-      def generate(name, options, recall = {}, parameterize = nil)
-        constraints = recall.merge(options)
+      def generate(name, options, path_parameters, parameterize = nil)
+        constraints = path_parameters.merge(options)
         missing_keys = []
 
         match_route(name, constraints) do |route|
-          parameterized_parts = extract_parameterized_parts(route, options, recall, parameterize)
+          parameterized_parts = extract_parameterized_parts(route, options, path_parameters, parameterize)
 
           # Skip this route unless a name has been provided or it is a
           # standard Rails route since we can't determine whether an options
diff --git a/actionpack/lib/action_dispatch/journey/parser.rb b/actionpack/lib/action_dispatch/journey/parser.rb
index d129ba7e16..9012297400 100644
--- a/actionpack/lib/action_dispatch/journey/parser.rb
+++ b/actionpack/lib/action_dispatch/journey/parser.rb
@@ -86,7 +86,7 @@ racc_token_table = {
 
 racc_nt_base = 10
 
-racc_use_result_var = true
+racc_use_result_var = false
 
 Racc_arg = [
   racc_action_table,
@@ -133,14 +133,12 @@ Racc_debug_parser = false
 
 # reduce 0 omitted
 
-def _reduce_1(val, _values, result)
- result = Cat.new(val.first, val.last) 
-    result
+def _reduce_1(val, _values)
+ Cat.new(val.first, val.last)
 end
 
-def _reduce_2(val, _values, result)
- result = val.first 
-    result
+def _reduce_2(val, _values)
+ val.first
 end
 
 # reduce 3 omitted
@@ -151,24 +149,20 @@ end
 
 # reduce 6 omitted
 
-def _reduce_7(val, _values, result)
- result = Group.new(val[1]) 
-    result
+def _reduce_7(val, _values)
+ Group.new(val[1])
 end
 
-def _reduce_8(val, _values, result)
- result = Or.new([val.first, val.last]) 
-    result
+def _reduce_8(val, _values)
+ Or.new([val.first, val.last])
 end
 
-def _reduce_9(val, _values, result)
- result = Or.new([val.first, val.last]) 
-    result
+def _reduce_9(val, _values)
+ Or.new([val.first, val.last])
 end
 
-def _reduce_10(val, _values, result)
- result = Star.new(Symbol.new(val.last)) 
-    result
+def _reduce_10(val, _values)
+ Star.new(Symbol.new(val.last))
 end
 
 # reduce 11 omitted
@@ -179,27 +173,23 @@ end
 
 # reduce 14 omitted
 
-def _reduce_15(val, _values, result)
- result = Slash.new('/') 
-    result
+def _reduce_15(val, _values)
+ Slash.new('/')
 end
 
-def _reduce_16(val, _values, result)
- result = Symbol.new(val.first) 
-    result
+def _reduce_16(val, _values)
+ Symbol.new(val.first)
 end
 
-def _reduce_17(val, _values, result)
- result = Literal.new(val.first) 
-    result
+def _reduce_17(val, _values)
+ Literal.new(val.first)
 end
 
-def _reduce_18(val, _values, result)
- result = Dot.new(val.first) 
-    result
+def _reduce_18(val, _values)
+ Dot.new(val.first)
 end
 
-def _reduce_none(val, _values, result)
+def _reduce_none(val, _values)
   val[0]
 end
 
diff --git a/actionpack/lib/action_dispatch/journey/parser.y b/actionpack/lib/action_dispatch/journey/parser.y
index 0ead222551..d3f7c4d765 100644
--- a/actionpack/lib/action_dispatch/journey/parser.y
+++ b/actionpack/lib/action_dispatch/journey/parser.y
@@ -1,11 +1,11 @@
 class ActionDispatch::Journey::Parser
-
+  options no_result_var
 token SLASH LITERAL SYMBOL LPAREN RPAREN DOT STAR OR
 
 rule
   expressions
-    : expression expressions  { result = Cat.new(val.first, val.last) }
-    | expression              { result = val.first }
+    : expression expressions  { Cat.new(val.first, val.last) }
+    | expression              { val.first }
     | or
     ;
   expression
@@ -14,14 +14,14 @@ rule
     | star
     ;
   group
-    : LPAREN expressions RPAREN { result = Group.new(val[1]) }
+    : LPAREN expressions RPAREN { Group.new(val[1]) }
     ;
   or
-    : expression OR expression { result = Or.new([val.first, val.last]) }
-    | expression OR or { result = Or.new([val.first, val.last]) }
+    : expression OR expression { Or.new([val.first, val.last]) }
+    | expression OR or { Or.new([val.first, val.last]) }
     ;
   star
-    : STAR       { result = Star.new(Symbol.new(val.last)) }
+    : STAR       { Star.new(Symbol.new(val.last)) }
     ;
   terminal
     : symbol
@@ -30,16 +30,16 @@ rule
     | dot
     ;
   slash
-    : SLASH              { result = Slash.new('/') }
+    : SLASH              { Slash.new('/') }
     ;
   symbol
-    : SYMBOL             { result = Symbol.new(val.first) }
+    : SYMBOL             { Symbol.new(val.first) }
     ;
   literal
-    : LITERAL            { result = Literal.new(val.first) }
+    : LITERAL            { Literal.new(val.first) }
     ;
   dot
-    : DOT                { result = Dot.new(val.first) }
+    : DOT                { Dot.new(val.first) }
     ;
 
 end
diff --git a/actionpack/lib/action_dispatch/middleware/cookies.rb b/actionpack/lib/action_dispatch/middleware/cookies.rb
index e069840b8e..ac9e5effe2 100644
--- a/actionpack/lib/action_dispatch/middleware/cookies.rb
+++ b/actionpack/lib/action_dispatch/middleware/cookies.rb
@@ -468,7 +468,7 @@ module ActionDispatch
           options = { :value => @verifier.generate(serialize(name, options)) }
         end
 
-        raise CookieOverflow if options[:value].size > MAX_COOKIE_SIZE
+        raise CookieOverflow if options[:value].bytesize > MAX_COOKIE_SIZE
         @parent_jar[name] = options
       end
 
@@ -526,7 +526,7 @@ module ActionDispatch
 
         options[:value] = @encryptor.encrypt_and_sign(serialize(name, options[:value]))
 
-        raise CookieOverflow if options[:value].size > MAX_COOKIE_SIZE
+        raise CookieOverflow if options[:value].bytesize > MAX_COOKIE_SIZE
         @parent_jar[name] = options
       end
 
diff --git a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
index 0ca1a87645..274f6f2f22 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
@@ -38,9 +38,7 @@ module ActionDispatch
         template = ActionView::Base.new([RESCUES_TEMPLATE_PATH],
           request: request,
           exception: wrapper.exception,
-          application_trace: wrapper.application_trace,
-          framework_trace: wrapper.framework_trace,
-          full_trace: wrapper.full_trace,
+          traces: traces_from_wrapper(wrapper),
           routes_inspector: routes_inspector(exception),
           source_extract: wrapper.source_extract,
           line_number: wrapper.line_number,
@@ -95,5 +93,36 @@ module ActionDispatch
         ActionDispatch::Routing::RoutesInspector.new(@routes_app.routes.routes)
       end
     end
+
+    # Augment the exception traces by providing ids for all unique stack frame
+    def traces_from_wrapper(wrapper)
+      application_trace = wrapper.application_trace
+      framework_trace = wrapper.framework_trace
+      full_trace = wrapper.full_trace
+
+      if application_trace && framework_trace
+        id_counter = 0
+
+        application_trace = application_trace.map do |trace|
+          prev = id_counter
+          id_counter += 1
+          { id: prev, trace: trace }
+        end
+
+        framework_trace = framework_trace.map do |trace|
+          prev = id_counter
+          id_counter += 1
+          { id: prev, trace: trace }
+        end
+
+        full_trace = application_trace + framework_trace
+      end
+
+      {
+        "Application Trace" => application_trace,
+        "Framework Trace" => framework_trace,
+        "Full Trace" => full_trace
+      }
+    end
   end
 end
diff --git a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
index 2326bb043a..b98b553c38 100644
--- a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
+++ b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
@@ -61,12 +61,15 @@ module ActionDispatch
     end
 
     def source_extract
-      if application_trace && trace = application_trace.first
-        file, line, _ = trace.split(":")
-        @file = file
-        @line_number = line.to_i
-        source_fragment(@file, @line_number)
-      end
+      exception.backtrace.map do |trace|
+        file, line = trace.split(":")
+        line_number = line.to_i
+        {
+          code: source_fragment(file, line_number),
+          file: file,
+          line_number: line_number
+        }
+      end if exception.backtrace
     end
 
     private
@@ -110,7 +113,7 @@ module ActionDispatch
     def expand_backtrace
       @exception.backtrace.unshift(
         @exception.to_s.split("\n")
-      ).flatten! 
+      ).flatten!
     end
   end
 end
diff --git a/actionpack/lib/action_dispatch/middleware/request_id.rb b/actionpack/lib/action_dispatch/middleware/request_id.rb
index 5d1740d0d4..25658bac3d 100644
--- a/actionpack/lib/action_dispatch/middleware/request_id.rb
+++ b/actionpack/lib/action_dispatch/middleware/request_id.rb
@@ -5,7 +5,7 @@ module ActionDispatch
   # Makes a unique request id available to the action_dispatch.request_id env variable (which is then accessible through
   # ActionDispatch::Request#uuid) and sends the same id to the client via the X-Request-Id header.
   #
-  # The unique request id is either based off the X-Request-Id header in the request, which would typically be generated
+  # The unique request id is either based on the X-Request-Id header in the request, which would typically be generated
   # by a firewall, load balancer, or the web server, or, if this header is not available, a random uuid. If the
   # header is accepted from the outside world, we sanitize it to a max of 255 chars and alphanumeric and dashes only.
   #
diff --git a/actionpack/lib/action_dispatch/middleware/session/cache_store.rb b/actionpack/lib/action_dispatch/middleware/session/cache_store.rb
index 1db6194271..625050dc4b 100644
--- a/actionpack/lib/action_dispatch/middleware/session/cache_store.rb
+++ b/actionpack/lib/action_dispatch/middleware/session/cache_store.rb
@@ -16,9 +16,9 @@ module ActionDispatch
 
       # Get a session from the cache.
       def get_session(env, sid)
-        sid ||= generate_sid
-        session = @cache.read(cache_key(sid))
-        session ||= {}
+        unless sid and session = @cache.read(cache_key(sid))
+          sid, session = generate_sid, {}
+        end
         [sid, session]
       end
 
diff --git a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
index 1d4f0f89a6..f0779279c1 100644
--- a/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/show_exceptions.rb
@@ -42,6 +42,7 @@ module ActionDispatch
       wrapper = ExceptionWrapper.new(env, exception)
       status  = wrapper.status_code
       env["action_dispatch.exception"] = wrapper.exception
+      env["action_dispatch.original_path"] = env["PATH_INFO"]
       env["PATH_INFO"] = "/#{status}"
       response = @exceptions_app.call(env)
       response[1]['X-Cascade'] == 'pass' ? pass_response(status) : response
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb
index 38429cb78e..51660a619b 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/_source.erb
@@ -1,25 +1,29 @@
 <% if @source_extract %>
-<div class="source">
-<div class="info">
-  Extracted source (around line <strong>#<%= @line_number %></strong>):
-</div>
-<div class="data">
-  <table cellpadding="0" cellspacing="0" class="lines">
-      <tr>
-        <td>
-          <pre class="line_numbers">
-            <% @source_extract.keys.each do |line_number| %>
+  <% @source_extract.each_with_index do |extract_source, index| %>
+    <% if extract_source[:code] %>
+      <div class="source <%="hidden" if index != 0%>" id="frame-source-<%=index%>">
+        <div class="info">
+          Extracted source (around line <strong>#<%= extract_source[:line_number] %></strong>):
+        </div>
+        <div class="data">
+          <table cellpadding="0" cellspacing="0" class="lines">
+            <tr>
+              <td>
+                <pre class="line_numbers">
+                  <% extract_source[:code].keys.each do |line_number| %>
 <span><%= line_number -%></span>
-            <% end %>
-          </pre>
-        </td>
+                  <% end %>
+                </pre>
+              </td>
 <td width="100%">
 <pre>
-<% @source_extract.each do |line, source| -%><div class="line<%= " active" if line == @line_number -%>"><%= source -%></div><% end -%>
+<% extract_source[:code].each do |line, source| -%><div class="line<%= " active" if line == extract_source[:line_number] -%>"><%= source -%></div><% end -%>
 </pre>
 </td>
-    </tr>
-  </table>
-</div>
-</div>
+            </tr>
+          </table>
+        </div>
+      </div>
+    <% end %>
+  <% end %>
 <% end %>
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
index b181909bff..f62caf51d7 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.html.erb
@@ -1,9 +1,4 @@
-<%
-   traces = { "Application Trace" => @application_trace,
-              "Framework Trace"   => @framework_trace,
-              "Full Trace"        => @full_trace }
-   names = traces.keys
-%>
+<% names = @traces.keys %>
 
 <p><code>Rails.root: <%= defined?(Rails) && Rails.respond_to?(:root) ? Rails.root : "unset" %></code></p>
 
@@ -16,9 +11,42 @@
     <a href="#" onclick="<%= hide.join %><%= show %>; return false;"><%= name %></a> <%= '|' unless names.last == name %>
   <% end %>
 
-  <% traces.each do |name, trace| %>
+  <% @traces.each do |name, trace| %>
     <div id="<%= name.gsub(/\s/, '-') %>" style="display: <%= (name == "Application Trace") ? 'block' : 'none' %>;">
-      <pre><code><%= trace.join "\n" %></code></pre>
+      <pre><code><% trace.each do |frame| %><a class="trace-frames" data-frame-id="<%= frame[:id] %>" href="#"><%= frame[:trace] %></a><br><% end %></code></pre>
     </div>
   <% end %>
+
+  <script type="text/javascript">
+    var traceFrames = document.getElementsByClassName('trace-frames');
+    var selectedFrame, currentSource = document.getElementById('frame-source-0');
+
+    // Add click listeners for all stack frames
+    for (var i = 0; i < traceFrames.length; i++) {
+      traceFrames[i].addEventListener('click', function(e) {
+        e.preventDefault();
+        var target = e.target;
+        var frame_id = target.dataset.frameId;
+
+        if (selectedFrame) {
+          selectedFrame.className = selectedFrame.className.replace("selected", "");
+        }
+
+        target.className += " selected";
+        selectedFrame = target;
+
+        // Change the extracted source code
+        changeSourceExtract(frame_id);
+      });
+
+      function changeSourceExtract(frame_id) {
+        var el = document.getElementById('frame-source-' + frame_id);
+        if (currentSource && el) {
+          currentSource.className += " hidden";
+          el.className = el.className.replace(" hidden", "");
+          currentSource = el;
+        }
+      }
+    }
+  </script>
 </div>
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb
index d4af5c9b06..36b01bf952 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/_trace.text.erb
@@ -1,15 +1,9 @@
-<%
-  traces = { "Application Trace" => @application_trace,
-             "Framework Trace"   => @framework_trace,
-             "Full Trace"        => @full_trace }
-%>
-
 Rails.root: <%= defined?(Rails) && Rails.respond_to?(:root) ? Rails.root : "unset" %>
 
-<% traces.each do |name, trace| %>
+<% @traces.each do |name, trace| %>
 <% if trace.any? %>
 <%= name %>
-<%= trace.join("\n") %>
+<%= trace.map(&:trace).join("\n") %>
 
 <% end %>
 <% end %>
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/layout.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/layout.erb
index bc5d03dc10..e0509f56f4 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/layout.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/layout.erb
@@ -116,9 +116,15 @@
       background-color: #FFCCCC;
     }
 
+    .hidden {
+      display: none;
+    }
+
     a { color: #980905; }
     a:visited { color: #666; }
+    a.trace-frames { color: #666; }
     a:hover { color: #C52F24; }
+    a.trace-frames.selected { color: #C52F24 }
 
     <%= yield :style %>
   </style>
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb
index 027a0f5b3e..c1e8b6cae3 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.html.erb
@@ -1,4 +1,3 @@
-<% @source_extract = @exception.source_extract(0, :html) %>
 <header>
   <h1>
     <%= @exception.original_exception.class.to_s %> in
@@ -12,29 +11,7 @@
   </p>
   <pre><code><%= h @exception.message %></code></pre>
 
-  <div class="source">
-    <div class="info">
-      <p>Extracted source (around line <strong>#<%= @exception.line_number %></strong>):</p>
-    </div>
-    <div class="data">
-    <table cellpadding="0" cellspacing="0" class="lines">
-      <tr>
-        <td>
-          <pre class="line_numbers">
-            <% @source_extract.keys.each do |line_number| %>
-<span><%= line_number -%></span>
-            <% end %>
-          </pre>
-        </td>
-<td width="100%">
-<pre>
-<% @source_extract.each do |line, source| -%><div class="line<%= " active" if line == @exception.line_number -%>"><%= source -%></div><% end -%>
-</pre>
-</td>
-    </tr>
-  </table>
-</div>
-</div>
+  <%= render template: "rescues/_source" %>
 
   <p><%= @exception.sub_template_message %></p>
 
diff --git a/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb b/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb
index 5da21d9784..77bcd26726 100644
--- a/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb
+++ b/actionpack/lib/action_dispatch/middleware/templates/rescues/template_error.text.erb
@@ -1,4 +1,3 @@
-<% @source_extract = @exception.source_extract(0, :html) %>
 <%= @exception.original_exception.class.to_s %> in <%= @request.parameters["controller"].camelize if @request.parameters["controller"] %>#<%= @request.parameters["action"] %>
 
 Showing <%= @exception.file_name %> where line #<%= @exception.line_number %> raised:
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 235a840682..cd94f35e8f 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -13,9 +13,6 @@ module ActionDispatch
   module Routing
     class Mapper
       URL_OPTIONS = [:protocol, :subdomain, :domain, :host, :port]
-      SCOPE_OPTIONS = [:path, :shallow_path, :as, :shallow_prefix, :module,
-                       :controller, :action, :path_names, :constraints,
-                       :shallow, :blocks, :defaults, :options]
 
       class Constraints < Endpoint #:nodoc:
         attr_reader :app, :constraints
@@ -66,7 +63,7 @@ module ActionDispatch
         attr_reader :requirements, :conditions, :defaults
         attr_reader :to, :default_controller, :default_action, :as, :anchor
 
-        def self.build(scope, path, options)
+        def self.build(scope, set, path, options)
           options = scope[:options].merge(options) if scope[:options]
 
           options.delete :only
@@ -77,12 +74,13 @@ module ActionDispatch
 
           defaults = (scope[:defaults] || {}).merge options.delete(:defaults) || {}
 
-          new scope, path, defaults, options
+          new scope, set, path, defaults, options
         end
 
-        def initialize(scope, path, defaults, options)
+        def initialize(scope, set, path, defaults, options)
           @requirements, @conditions = {}, {}
           @defaults = defaults
+          @set = set
 
           @to                 = options.delete :to
           @default_controller = options.delete(:controller) || scope[:controller]
@@ -249,9 +247,9 @@ module ActionDispatch
               Constraints.new(to, blocks, false)
             else
               if blocks.any?
-                Constraints.new(dispatcher, blocks, true)
+                Constraints.new(dispatcher(defaults), blocks, true)
               else
-                dispatcher
+                dispatcher(defaults)
               end
             end
           end
@@ -348,8 +346,8 @@ module ActionDispatch
             parser.parse path
           end
 
-          def dispatcher
-            Routing::RouteSet::Dispatcher.new(defaults)
+          def dispatcher(defaults)
+            @set.dispatcher defaults
           end
       end
 
@@ -576,13 +574,21 @@ module ActionDispatch
 
           raise "A rack application must be specified" unless path
 
-          options[:as]  ||= app_name(app)
+          rails_app = rails_app? app
+
+          if rails_app
+            options[:as]  ||= app.railtie_name
+          else
+            # non rails apps can't have an :as
+            options[:as]  = nil
+          end
+
           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, target_as)
+          define_generate_prefix(app, target_as) if rails_app
           self
         end
 
@@ -603,31 +609,24 @@ module ActionDispatch
         end
 
         private
-          def app_name(app)
-            return unless app.respond_to?(:routes)
-
-            if app.respond_to?(:railtie_name)
-              app.railtie_name
-            else
-              class_name = app.class.is_a?(Class) ? app.name : app.class.name
-              ActiveSupport::Inflector.underscore(class_name).tr("/", "_")
-            end
+          def rails_app?(app)
+            app.is_a?(Class) && app < Rails::Railtie
           end
 
           def define_generate_prefix(app, name)
-            return unless app.respond_to?(:routes) && app.routes.respond_to?(:define_mounted_helper)
-
-            _route = @set.named_routes.routes[name.to_sym]
+            _route = @set.named_routes.get name
             _routes = @set
             app.routes.define_mounted_helper(name)
             app.routes.extend Module.new {
-              def mounted?; true; end
+              def optimize_routes_generation?; false; end
               define_method :find_script_name do |options|
-                super(options) || begin
-                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) }
-                _routes.url_helpers.send("#{name}_path", prefix_options)
+                if options.key? :script_name
+                  super(options)
+                else
+                  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) }
+                  _routes.url_helpers.send("#{name}_path", prefix_options)
                 end
               end
             }
@@ -771,7 +770,7 @@ module ActionDispatch
         #   end
         def scope(*args)
           options = args.extract_options!.dup
-          recover = {}
+          scope = {}
 
           options[:path] = args.flatten.join('/') if args.any?
           options[:constraints] ||= {}
@@ -791,7 +790,7 @@ module ActionDispatch
             block, options[:constraints] = options[:constraints], {}
           end
 
-          SCOPE_OPTIONS.each do |option|
+          @scope.options.each do |option|
             if option == :blocks
               value = block
             elsif option == :options
@@ -801,15 +800,15 @@ module ActionDispatch
             end
 
             if value
-              recover[option] = @scope[option]
-              @scope[option]  = send("merge_#{option}_scope", @scope[option], value)
+              scope[option] = send("merge_#{option}_scope", @scope[option], value)
             end
           end
 
+          @scope = @scope.new scope
           yield
           self
         ensure
-          @scope.merge!(recover)
+          @scope = @scope.parent
         end
 
         # Scopes routes to a specific controller
@@ -1545,13 +1544,13 @@ module ActionDispatch
             action = nil
           end
 
-          if !options.fetch(:as, true)
+          if !options.fetch(:as, true) # if it's set to nil or false
             options.delete(:as)
           else
             options[:as] = name_for_action(options[:as], action)
           end
 
-          mapping = Mapping.build(@scope, URI.parser.escape(path), options)
+          mapping = Mapping.build(@scope, @set, URI.parser.escape(path), options)
           app, conditions, requirements, defaults, as, anchor = mapping.to_route
           @set.add_route(app, conditions, requirements, defaults, as, anchor)
         end
@@ -1645,27 +1644,26 @@ module ActionDispatch
 
           def with_exclusive_scope
             begin
-              old_name_prefix, old_path = @scope[:as], @scope[:path]
-              @scope[:as], @scope[:path] = nil, nil
+              @scope = @scope.new(:as => nil, :path => nil)
 
               with_scope_level(:exclusive) do
                 yield
               end
             ensure
-              @scope[:as], @scope[:path] = old_name_prefix, old_path
+              @scope = @scope.parent
             end
           end
 
           def with_scope_level(kind)
-            old, @scope[:scope_level] = @scope[:scope_level], kind
+            @scope = @scope.new(:scope_level => kind)
             yield
           ensure
-            @scope[:scope_level] = old
+            @scope = @scope.parent
           end
 
           def resource_scope(kind, resource) #:nodoc:
             resource.shallow = @scope[:shallow]
-            old_resource, @scope[:scope_level_resource] = @scope[:scope_level_resource], resource
+            @scope = @scope.new(:scope_level_resource => resource)
             @nesting.push(resource)
 
             with_scope_level(kind) do
@@ -1673,7 +1671,7 @@ module ActionDispatch
             end
           ensure
             @nesting.pop
-            @scope[:scope_level_resource] = old_resource
+            @scope = @scope.parent
           end
 
           def nested_options #:nodoc:
@@ -1706,12 +1704,13 @@ module ActionDispatch
           end
 
           def shallow_scope(path, options = {}) #:nodoc:
-            old_name_prefix, old_path = @scope[:as], @scope[:path]
-            @scope[:as], @scope[:path] = @scope[:shallow_prefix], @scope[:shallow_path]
+            scope = { :as   => @scope[:shallow_prefix],
+                      :path => @scope[:shallow_path] }
+            @scope = @scope.new scope
 
             scope(path, options) { yield }
           ensure
-            @scope[:as], @scope[:path] = old_name_prefix, old_path
+            @scope = @scope.parent
           end
 
           def path_for_action(action, path) #:nodoc:
@@ -1768,7 +1767,7 @@ module ActionDispatch
               # and return nil in case it isn't. Otherwise, we pass the invalid name
               # forward so the underlying router engine treats it and raises an exception.
               if as.nil?
-                candidate unless @set.routes.find { |r| r.name == candidate } || candidate !~ /\A[_a-z]/i
+                candidate unless candidate !~ /\A[_a-z]/i || @set.named_routes.key?(candidate)
               else
                 candidate
               end
@@ -1893,9 +1892,38 @@ module ActionDispatch
         end
       end
 
+      class Scope # :nodoc:
+        OPTIONS = [:path, :shallow_path, :as, :shallow_prefix, :module,
+                   :controller, :action, :path_names, :constraints,
+                   :shallow, :blocks, :defaults, :options]
+
+        attr_reader :parent
+
+        def initialize(hash, parent = {})
+          @hash = hash
+          @parent = parent
+        end
+
+        def options
+          OPTIONS
+        end
+
+        def new(hash)
+          self.class.new hash, self
+        end
+
+        def [](key)
+          @hash.fetch(key) { @parent[key] }
+        end
+
+        def []=(k,v)
+          @hash[k] = v
+        end
+      end
+
       def initialize(set) #:nodoc:
         @set = set
-        @scope = { :path_names => @set.resources_path_names }
+        @scope = Scope.new({ :path_names => @set.resources_path_names })
         @concerns = {}
         @nesting = []
       end
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index 69535faabd..5b3651aaee 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -86,36 +86,64 @@ module ActionDispatch
       # named routes.
       class NamedRouteCollection #:nodoc:
         include Enumerable
-        attr_reader :routes, :helpers, :module
+        attr_reader :routes, :url_helpers_module
 
         def initialize
           @routes  = {}
-          @helpers = []
-          @module  = Module.new
+          @path_helpers = Set.new
+          @url_helpers = Set.new
+          @url_helpers_module  = Module.new
+          @path_helpers_module = Module.new
+        end
+
+        def route_defined?(name)
+          key = name.to_sym
+          @path_helpers.include?(key) || @url_helpers.include?(key)
         end
 
         def helper_names
-          @helpers.map(&:to_s)
+          @path_helpers.map(&:to_s) + @url_helpers.map(&:to_s)
         end
 
         def clear!
-          @helpers.each do |helper|
-            @module.remove_possible_method helper
+          @path_helpers.each do |helper|
+            @path_helpers_module.send :undef_method, helper
+          end
+
+          @url_helpers.each do |helper|
+            @url_helpers_module.send  :undef_method, helper
           end
 
           @routes.clear
-          @helpers.clear
+          @path_helpers.clear
+          @url_helpers.clear
         end
 
         def add(name, route)
-          routes[name.to_sym] = route
-          define_named_route_methods(name, route)
+          key       = name.to_sym
+          path_name = :"#{name}_path"
+          url_name  = :"#{name}_url"
+
+          if routes.key? key
+            @path_helpers_module.send :undef_method, path_name
+            @url_helpers_module.send  :undef_method, url_name
+          end
+          routes[key] = route
+          define_url_helper @path_helpers_module, route, path_name, route.defaults, name, PATH
+          define_url_helper @url_helpers_module,  route, url_name,  route.defaults, name, FULL
+
+          @path_helpers << path_name
+          @url_helpers << url_name
         end
 
         def get(name)
           routes[name.to_sym]
         end
 
+        def key?(name)
+          routes.key? name.to_sym
+        end
+
         alias []=   add
         alias []    get
         alias clear clear!
@@ -133,12 +161,31 @@ module ActionDispatch
           routes.length
         end
 
+        def path_helpers_module(warn = false)
+          if warn
+            mod = @path_helpers_module
+            helpers = @path_helpers
+            Module.new do
+              include mod
+
+              helpers.each do |meth|
+                define_method(meth) do |*args, &block|
+                  ActiveSupport::Deprecation.warn("The method `#{meth}` cannot be used here as a full URL is required. Use `#{meth.to_s.sub(/_path$/, '_url')}` instead")
+                  super(*args, &block)
+                end
+              end
+            end
+          else
+            @path_helpers_module
+          end
+        end
+
         class UrlHelper # :nodoc:
-          def self.create(route, options)
+          def self.create(route, options, route_name, url_strategy)
             if optimize_helper?(route)
-              OptimizedUrlHelper.new(route, options)
+              OptimizedUrlHelper.new(route, options, route_name, url_strategy)
             else
-              new route, options
+              new route, options, route_name, url_strategy
             end
           end
 
@@ -146,20 +193,22 @@ module ActionDispatch
             !route.glob? && route.path.requirements.empty?
           end
 
+          attr_reader :url_strategy, :route_name
+
           class OptimizedUrlHelper < UrlHelper # :nodoc:
             attr_reader :arg_size
 
-            def initialize(route, options)
+            def initialize(route, options, route_name, url_strategy)
               super
               @required_parts = @route.required_parts
               @arg_size       = @required_parts.size
             end
 
-            def call(t, args)
-              if args.size == arg_size && !args.last.is_a?(Hash) && optimize_routes_generation?(t)
+            def call(t, args, inner_options)
+              if args.size == arg_size && !inner_options && optimize_routes_generation?(t)
                 options = t.url_options.merge @options
                 options[:path] = optimized_helper(args)
-                ActionDispatch::Http::URL.url_for(options)
+                url_strategy.call options
               else
                 super
               end
@@ -201,21 +250,27 @@ module ActionDispatch
             end
           end
 
-          def initialize(route, options)
+          def initialize(route, options, route_name, url_strategy)
             @options      = options
             @segment_keys = route.segment_keys.uniq
             @route        = route
+            @url_strategy = url_strategy
+            @route_name   = route_name
           end
 
-          def call(t, args)
+          def call(t, args, inner_options)
             controller_options = t.url_options
             options = controller_options.merge @options
-            hash = handle_positional_args(controller_options, args, options, @segment_keys)
-            t._routes.url_for(hash)
+            hash = handle_positional_args(controller_options,
+                                          inner_options || {},
+                                          args,
+                                          options,
+                                          @segment_keys)
+
+            t._routes.url_for(hash, route_name, url_strategy)
           end
 
-          def handle_positional_args(controller_options, args, result, path_params)
-            inner_options = args.extract_options!
+          def handle_positional_args(controller_options, inner_options, args, result, path_params)
 
             if args.size > 0
               if args.size < path_params.size - 1 # take format into account
@@ -245,27 +300,25 @@ module ActionDispatch
         #
         #   foo_url(bar, baz, bang, sort_by: 'baz')
         #
-        def define_url_helper(route, name, options)
-          helper = UrlHelper.create(route, options.dup)
-
-          @module.remove_possible_method name
-          @module.module_eval do
+        def define_url_helper(mod, route, name, opts, route_key, url_strategy)
+          helper = UrlHelper.create(route, opts, route_key, url_strategy)
+          mod.module_eval do
             define_method(name) do |*args|
-              helper.call self, args
+              options = nil
+              options = args.pop if args.last.is_a? Hash
+              helper.call self, args, options
             end
           end
-
-          helpers << name
-        end
-
-        def define_named_route_methods(name, route)
-          define_url_helper route, :"#{name}_path",
-            route.defaults.merge(:use_route => name, :only_path => true)
-          define_url_helper route, :"#{name}_url",
-            route.defaults.merge(:use_route => name, :only_path => false)
         end
       end
 
+      # :stopdoc:
+      # strategy for building urls to send to the client
+      PATH    = ->(options) { ActionDispatch::Http::URL.path_for(options) }
+      FULL    = ->(options) { ActionDispatch::Http::URL.full_url_for(options) }
+      UNKNOWN = ->(options) { ActionDispatch::Http::URL.url_for(options) }
+      # :startdoc:
+
       attr_accessor :formatter, :set, :named_routes, :default_scope, :router
       attr_accessor :disable_clear_and_finalize, :resources_path_names
       attr_accessor :default_url_options, :request_class
@@ -278,7 +331,7 @@ module ActionDispatch
 
       def initialize(request_class = ActionDispatch::Request)
         self.named_routes = NamedRouteCollection.new
-        self.resources_path_names = self.class.default_resources_path_names.dup
+        self.resources_path_names = self.class.default_resources_path_names
         self.default_url_options = {}
         self.request_class = request_class
 
@@ -319,6 +372,7 @@ module ActionDispatch
           mapper.instance_exec(&block)
         end
       end
+      private :eval_block
 
       def finalize!
         return if @finalized
@@ -334,6 +388,10 @@ module ActionDispatch
         @prepend.each { |blk| eval_block(blk) }
       end
 
+      def dispatcher(defaults)
+        Routing::RouteSet::Dispatcher.new(defaults)
+      end
+
       module MountedHelpers #:nodoc:
         extend ActiveSupport::Concern
         include UrlFor
@@ -364,42 +422,51 @@ module ActionDispatch
         RUBY
       end
 
-      def url_helpers
-        @url_helpers ||= begin
-          routes = self
-
-          Module.new do
-            extend ActiveSupport::Concern
-            include UrlFor
-
-            # Define url_for in the singleton level so one can do:
-            # Rails.application.routes.url_helpers.url_for(args)
-            @_routes = routes
-            class << self
-              delegate :url_for, :optimize_routes_generation?, :to => '@_routes'
-              attr_reader :_routes
-              def url_options; {}; end
-            end
+      def url_helpers(include_path_helpers = true)
+        routes = self
 
-            # Make named_routes available in the module singleton
-            # as well, so one can do:
-            # Rails.application.routes.url_helpers.posts_path
-            extend routes.named_routes.module
+        Module.new do
+          extend ActiveSupport::Concern
+          include UrlFor
+
+          # Define url_for in the singleton level so one can do:
+          # Rails.application.routes.url_helpers.url_for(args)
+          @_routes = routes
+          class << self
+            delegate :url_for, :optimize_routes_generation?, to: '@_routes'
+            attr_reader :_routes
+            def url_options; {}; end
+          end
 
-            # Any class that includes this module will get all
-            # named routes...
-            include routes.named_routes.module
+          url_helpers = routes.named_routes.url_helpers_module
 
-            # plus a singleton class method called _routes ...
-            included do
-              singleton_class.send(:redefine_method, :_routes) { routes }
-            end
+          # Make named_routes available in the module singleton
+          # as well, so one can do:
+          # Rails.application.routes.url_helpers.posts_path
+          extend url_helpers
 
-            # And an instance method _routes. Note that
-            # UrlFor (included in this module) add extra
-            # conveniences for working with @_routes.
-            define_method(:_routes) { @_routes || routes }
+          # Any class that includes this module will get all
+          # named routes...
+          include url_helpers
+
+          if include_path_helpers
+            path_helpers = routes.named_routes.path_helpers_module
+          else
+            path_helpers = routes.named_routes.path_helpers_module(true)
           end
+
+          include path_helpers
+          extend path_helpers
+
+          # plus a singleton class method called _routes ...
+          included do
+            singleton_class.send(:redefine_method, :_routes) { routes }
+          end
+
+          # And an instance method _routes. Note that
+          # UrlFor (included in this module) add extra
+          # conveniences for working with @_routes.
+          define_method(:_routes) { @_routes || routes }
         end
       end
 
@@ -491,8 +558,8 @@ module ActionDispatch
 
         attr_reader :options, :recall, :set, :named_route
 
-        def initialize(options, recall, set)
-          @named_route = options.delete(:use_route)
+        def initialize(named_route, options, recall, set)
+          @named_route = named_route
           @options     = options.dup
           @recall      = recall.dup
           @set         = set
@@ -608,32 +675,34 @@ module ActionDispatch
       end
 
       def generate_extras(options, recall={})
-        path, params = generate(options, recall)
+        route_key = options.delete :use_route
+        path, params = generate(route_key, options, recall)
         return path, params.keys
       end
 
-      def generate(options, recall = {})
-        Generator.new(options, recall, self).generate
+      def generate(route_key, options, recall = {})
+        Generator.new(route_key, options, recall, self).generate
       end
+      private :generate
 
       RESERVED_OPTIONS = [:host, :protocol, :port, :subdomain, :domain, :tld_length,
                           :trailing_slash, :anchor, :params, :only_path, :script_name,
                           :original_script_name]
 
-      def mounted?
-        false
-      end
-
       def optimize_routes_generation?
-        !mounted? && default_url_options.empty?
+        default_url_options.empty?
       end
 
       def find_script_name(options)
-        options.delete :script_name
+        options.delete(:script_name) { '' }
+      end
+
+      def path_for(options, route_name = nil) # :nodoc:
+        url_for(options, route_name, PATH)
       end
 
       # The +options+ argument must be a hash whose keys are *symbols*.
-      def url_for(options)
+      def url_for(options, route_name = nil, url_strategy = UNKNOWN)
         options = default_url_options.merge options
 
         user = password = nil
@@ -648,14 +717,14 @@ module ActionDispatch
         original_script_name = options.delete(:original_script_name)
         script_name = find_script_name options
 
-        if script_name && original_script_name
+        if original_script_name
           script_name = original_script_name + script_name
         end
 
         path_options = options.dup
         RESERVED_OPTIONS.each { |ro| path_options.delete ro }
 
-        path, params = generate(path_options, recall)
+        path, params = generate(route_name, path_options, recall)
 
         if options.key? :params
           params.merge! options[:params]
@@ -667,7 +736,7 @@ module ActionDispatch
         options[:user]        = user
         options[:password]    = password
 
-        ActionDispatch::Http::URL.url_for(options)
+        url_strategy.call options
       end
 
       def call(env)
diff --git a/actionpack/lib/action_dispatch/routing/url_for.rb b/actionpack/lib/action_dispatch/routing/url_for.rb
index e624fe3c4a..eb554ec383 100644
--- a/actionpack/lib/action_dispatch/routing/url_for.rb
+++ b/actionpack/lib/action_dispatch/routing/url_for.rb
@@ -152,7 +152,9 @@ module ActionDispatch
         when nil
           _routes.url_for(url_options.symbolize_keys)
         when Hash
-          _routes.url_for(options.symbolize_keys.reverse_merge!(url_options))
+          route_name = options.delete :use_route
+          _routes.url_for(options.symbolize_keys.reverse_merge!(url_options),
+                         route_name)
         when String
           options
         when Symbol
@@ -169,8 +171,7 @@ module ActionDispatch
       protected
 
       def optimize_routes_generation?
-        return @_optimized_routes if defined?(@_optimized_routes)
-        @_optimized_routes = _routes.optimize_routes_generation? && default_url_options.empty?
+        _routes.optimize_routes_generation? && default_url_options.empty?
       end
 
       def _with_routes(routes)
diff --git a/actionpack/lib/action_dispatch/testing/assertions/response.rb b/actionpack/lib/action_dispatch/testing/assertions/response.rb
index 0adc6c84ff..13a72220b3 100644
--- a/actionpack/lib/action_dispatch/testing/assertions/response.rb
+++ b/actionpack/lib/action_dispatch/testing/assertions/response.rb
@@ -73,13 +73,8 @@ module ActionDispatch
           if Regexp === fragment
             fragment
           else
-            handle = @controller || Class.new(ActionController::Metal) do
-              include ActionController::Redirecting
-              def initialize(request)
-                @_request = request
-              end
-            end.new(@request)
-            handle._compute_redirect_to_location(fragment)
+            handle = @controller || ActionController::Redirecting
+            handle._compute_redirect_to_location(@request, fragment)
           end
         end
     end
diff --git a/actionpack/lib/action_dispatch/testing/assertions/routing.rb b/actionpack/lib/action_dispatch/testing/assertions/routing.rb
index f1f998d932..2cf38a9c2d 100644
--- a/actionpack/lib/action_dispatch/testing/assertions/routing.rb
+++ b/actionpack/lib/action_dispatch/testing/assertions/routing.rb
@@ -165,7 +165,7 @@ module ActionDispatch
 
       # ROUTES TODO: These assertions should really work in an integration context
       def method_missing(selector, *args, &block)
-        if defined?(@controller) && @controller && @routes && @routes.named_routes.helpers.include?(selector)
+        if defined?(@controller) && @controller && @routes && @routes.named_routes.route_defined?(selector)
           @controller.send(selector, *args, &block)
         else
           super
diff --git a/actionpack/lib/action_dispatch/testing/integration.rb b/actionpack/lib/action_dispatch/testing/integration.rb
index e326776bbc..2d1c3ac5c7 100644
--- a/actionpack/lib/action_dispatch/testing/integration.rb
+++ b/actionpack/lib/action_dispatch/testing/integration.rb
@@ -3,6 +3,7 @@ require 'uri'
 require 'active_support/core_ext/kernel/singleton_class'
 require 'active_support/core_ext/object/try'
 require 'rack/test'
+require 'minitest'
 
 module ActionDispatch
   module Integration #:nodoc:
@@ -200,7 +201,7 @@ module ActionDispatch
         @url_options ||= default_url_options.dup.tap do |url_options|
           url_options.reverse_merge!(controller.url_options) if controller
 
-          if @app.respond_to?(:routes) && @app.routes.respond_to?(:default_url_options)
+          if @app.respond_to?(:routes)
             url_options.reverse_merge!(@app.routes.default_url_options)
           end
 
@@ -329,6 +330,7 @@ module ActionDispatch
          xml_http_request xhr get_via_redirect post_via_redirect).each do |method|
         define_method(method) do |*args|
           reset! unless integration_session
+          reset_template_assertion
           # reset the html_document variable, but only for new get/post calls
           @html_document = nil unless method == 'cookies' || method == 'assigns'
           integration_session.__send__(method, *args).tap do