From 305d2f99edc0d228e18fe67632f73efe66567ccf Mon Sep 17 00:00:00 2001
From: Thomas Reynolds <me@tdreyno.com>
Date: Wed, 1 Jan 2014 21:19:05 -0800
Subject: [PATCH] Put template rendering in a jail

---
 .travis.yml                                   |   1 +
 .../lib/middleman-core/application.rb         |  16 +--
 .../lib/middleman-core/config_context.rb      |  20 ++-
 .../core_extensions/extensions.rb             |   5 +
 .../core_extensions/external_helpers.rb       |   2 +-
 .../core_extensions/front_matter.rb           |  12 +-
 .../core_extensions/rendering.rb              | 131 +++---------------
 .../lib/middleman-core/extension.rb           |   9 +-
 .../lib/middleman-core/renderers/haml.rb      |  30 +++-
 .../lib/middleman-core/renderers/kramdown.rb  |   8 +-
 .../lib/middleman-core/renderers/markdown.rb  |   2 -
 .../lib/middleman-core/renderers/redcarpet.rb |  14 +-
 .../lib/middleman-core/renderers/sass.rb      |   2 +-
 middleman-core/lib/middleman-core/sitemap.rb  |   2 +-
 .../lib/middleman-core/template_context.rb    | 105 ++++++++++++++
 .../core_extensions/default_helpers.rb        |  35 +++--
 .../lib/middleman-more/extensions/gzip.rb     |   8 +-
 17 files changed, 233 insertions(+), 169 deletions(-)
 create mode 100644 middleman-core/lib/middleman-core/template_context.rb

diff --git a/.travis.yml b/.travis.yml
index d10d9c65..520228b1 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -10,6 +10,7 @@ matrix:
   fast_finish: true
   allow_failures:
     - rvm: ruby-head
+    - rvm: 2.1.0
     - rvm: jruby-19mode
 env: TEST=true
 before_install: git submodule update --init --recursive
diff --git a/middleman-core/lib/middleman-core/application.rb b/middleman-core/lib/middleman-core/application.rb
index 625e974e..4103c2b2 100644
--- a/middleman-core/lib/middleman-core/application.rb
+++ b/middleman-core/lib/middleman-core/application.rb
@@ -44,15 +44,6 @@ module Middleman
     # Runs after the build is finished
     define_hook :after_build
 
-    # Mix-in helper methods. Accepts either a list of Modules
-    # and/or a block to be evaluated
-    # @return [void]
-    def self.helpers(*extensions, &block)
-      class_eval(&block)   if block_given?
-      include(*extensions) if extensions.any?
-    end
-    delegate :helpers, :to => :"self.class"
-
     # Root project directory (overwritten in middleman build/server)
     # @return [String]
     def self.root
@@ -170,11 +161,16 @@ module Middleman
     # Template cache
     attr_reader :cache
 
+    attr_reader :generic_template_context
+    delegate :link_to, :image_tag, :to => :generic_template_context
+
     # Initialize the Middleman project
     def initialize(&block)
       @cache = ::Tilt::Cache.new
       @logger = ::Middleman::Logger.singleton
-      @config_context = ConfigContext.new(self)
+      @template_context_class = Class.new(Middleman::TemplateContext)
+      @generic_template_context = @template_context_class.new(self)
+      @config_context = ConfigContext.new(self, @template_context_class)
 
       # Setup the default values from calls to set before initialization
       self.class.config.load_settings(self.class.superclass.config.all_settings)
diff --git a/middleman-core/lib/middleman-core/config_context.rb b/middleman-core/lib/middleman-core/config_context.rb
index 358dc9f2..40e7ef88 100644
--- a/middleman-core/lib/middleman-core/config_context.rb
+++ b/middleman-core/lib/middleman-core/config_context.rb
@@ -6,16 +6,32 @@ module Middleman
     attr_reader :app
 
     # Whitelist methods that can reach out.
-    delegate :config, :logger, :activate, :use, :map, :mime_type, :data, :helpers, :template_extensions, :root, :to => :app
+    delegate :config, :logger, :activate, :use, :map, :mime_type, :data, :template_extensions, :root, :to => :app
 
-    def initialize(app)
+    def initialize(app, template_context_class)
       @app = app
+      @template_context_class = template_context_class
+
       @ready_callbacks = []
       @after_build_callbacks = []
       @after_configuration_callbacks = []
       @configure_callbacks = {}
     end
 
+    def helpers(*helper_modules, &block)
+      helper_modules ||= []
+
+      if block_given?
+        block_module = Module.new
+        block_module.module_eval(&block)
+        helper_modules << block_module
+      end
+
+      helper_modules.each do |mod|
+        @template_context_class.send :include, mod
+      end
+    end
+
     def ready(&block)
       @ready_callbacks << block
     end
diff --git a/middleman-core/lib/middleman-core/core_extensions/extensions.rb b/middleman-core/lib/middleman-core/core_extensions/extensions.rb
index 4b1354b8..9dfea24c 100644
--- a/middleman-core/lib/middleman-core/core_extensions/extensions.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/extensions.rb
@@ -182,6 +182,11 @@ module Middleman
             end
 
             if klass.is_a?(::Middleman::Extension)
+              # Forward Extension helpers to TemplateContext
+              (klass.class.defined_helpers || []).each do |m|
+                @template_context_class.send(:include, m)
+              end
+
               ::Middleman::Extension.activated_extension(klass)
             end
           end
diff --git a/middleman-core/lib/middleman-core/core_extensions/external_helpers.rb b/middleman-core/lib/middleman-core/core_extensions/external_helpers.rb
index f30c0d3a..8cc5022e 100644
--- a/middleman-core/lib/middleman-core/core_extensions/external_helpers.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/external_helpers.rb
@@ -24,7 +24,7 @@ module Middleman
             require filename
             next unless Object.const_defined?(module_name.to_sym)
 
-            helpers Object.const_get(module_name.to_sym)
+            @template_context_class.send :include, Object.const_get(module_name.to_sym)
           end
         end
       end
diff --git a/middleman-core/lib/middleman-core/core_extensions/front_matter.rb b/middleman-core/lib/middleman-core/core_extensions/front_matter.rb
index 87f0f9cb..d967e204 100644
--- a/middleman-core/lib/middleman-core/core_extensions/front_matter.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/front_matter.rb
@@ -81,13 +81,11 @@ module Middleman::CoreExtensions
       end
     end
 
-    helpers do
-      # Get the template data from a path
-      # @param [String] path
-      # @return [String]
-      def template_data_for_file(path)
-        extensions[:frontmatter].data(path).last
-      end
+    # Get the template data from a path
+    # @param [String] path
+    # @return [String]
+    def template_data_for_file(path)
+      data(path).last
     end
 
     def data(path)
diff --git a/middleman-core/lib/middleman-core/core_extensions/rendering.rb b/middleman-core/lib/middleman-core/core_extensions/rendering.rb
index 0bde0104..734b9195 100644
--- a/middleman-core/lib/middleman-core/core_extensions/rendering.rb
+++ b/middleman-core/lib/middleman-core/core_extensions/rendering.rb
@@ -1,13 +1,8 @@
-# Shutup Tilt Warnings
-# @private
-class Tilt::Template
-  def warn(*args)
-    # Kernel.warn(*args)
-  end
-end
+require 'middleman-core/template_context'
 
 # Rendering extension
 module Middleman
+
   module CoreExtensions
     module Rendering
 
@@ -136,16 +131,17 @@ module Middleman
             ::I18n.locale = opts[:lang] if opts[:lang]
           end
 
-          # Use a dup of self as a context so that instance variables set within
-          # the template don't persist for other templates.
-          context = self.dup
+          # Sandboxed class for template eval
+          context = @template_context_class.new(self, locs, opts)
+
+          if context.respond_to?(:init_haml_helpers)
+            context.init_haml_helpers
+          end
+
           blocks.each do |block|
             context.instance_eval(&block)
           end
 
-          # Store current locs/opts for later
-          @current_locs = locs, @current_opts = opts
-
           # Keep rendering template until we've used up all extensions. This
           # handles cases like `style.css.sass.erb`
           content = nil
@@ -170,60 +166,6 @@ module Middleman
           # Pop all the saved variables from earlier as we may be returning to a
           # previous render (layouts, partials, nested layouts).
           ::I18n.locale = old_locale if defined?(::I18n)
-          @content_blocks = nil
-          @current_locs = nil
-          @current_opts = nil
-        end
-
-        # Sinatra/Padrino compatible render method signature referenced by some view
-        # helpers. Especially partials.
-        #
-        # @param [String, Symbol] engine
-        # @param [String, Symbol] data
-        # @param [Hash] options
-        # @return [String]
-        def render(engine, data, options={}, &block)
-          data = data.to_s
-
-          locals = options[:locals]
-
-          found_partial = false
-          engine        = nil
-
-          # If the path is known to the sitemap
-          if resource = sitemap.find_resource_by_path(current_path)
-            current_dir = File.dirname(resource.source_file)
-            engine = File.extname(resource.source_file)[1..-1].to_sym
-
-            # Look for partials relative to the current path
-            relative_dir = File.join(current_dir.sub(%r{^#{Regexp.escape(self.source_dir)}/?}, ''), data)
-
-            # Try to use the current engine first
-            found_partial, found_engine = resolve_template(relative_dir, :preferred_engine => engine, :try_without_underscore => true)
-
-            # Fall back to any engine available
-            if !found_partial
-              found_partial, found_engine = resolve_template(relative_dir, :try_without_underscore => true)
-            end
-          end
-
-          # Look in the partials_dir for the partial with the current engine
-          partials_path = File.join(config[:partials_dir], data)
-          if !found_partial && !engine.nil?
-            found_partial, found_engine = resolve_template(partials_path, :preferred_engine => engine, :try_without_underscore => true)
-          end
-
-          # Look in the root with any engine
-          if !found_partial
-            found_partial, found_engine = resolve_template(partials_path, :try_without_underscore => true)
-          end
-
-          # Render the partial if found, otherwide throw exception
-          if found_partial
-            render_individual_file(found_partial, locals, options, self, &block)
-          else
-            raise ::Middleman::CoreExtensions::Rendering::TemplateNotFound, "Could not locate partial: #{data}"
-          end
         end
 
         # Render an on-disk file. Used for everything, including layouts.
@@ -233,7 +175,7 @@ module Middleman
         # @param [Hash] opts
         # @param [Class] context
         # @return [String]
-        def render_individual_file(path, locs = {}, opts = {}, context = self, &block)
+        def render_individual_file(path, locs = {}, opts = {}, context, &block)
           path = path.to_s
 
           # Detect the remdering engine from the extension
@@ -244,7 +186,7 @@ module Middleman
           context.current_engine, engine_was = engine, context.current_engine
 
           # Save current buffer for later
-          @_out_buf, _buf_was = '', @_out_buf
+          _buf_was = context.save_buffer
 
           # Read from disk or cache the contents of the file
           body = if opts[:template_body]
@@ -287,7 +229,7 @@ module Middleman
           output
         ensure
           # Reset stored buffer
-          @_out_buf = _buf_was
+          context.restore_buffer(_buf_was)
           context.current_engine = engine_was
         end
 
@@ -295,7 +237,11 @@ module Middleman
         # @param [String] path
         # @return [String]
         def template_data_for_file(path)
-          File.read(File.expand_path(path, source_dir))
+          if extensions[:frontmatter]
+            extensions[:frontmatter].template_data_for_file(path)
+          else
+            File.read(File.expand_path(path, source_dir))
+          end
         end
 
         # Get a hash of configuration options for a given file extension, from
@@ -393,49 +339,6 @@ module Middleman
           layout_path
         end
 
-        # Allow layouts to be wrapped in the contents of other layouts
-        # @param [String, Symbol] layout_name
-        # @return [void]
-        def wrap_layout(layout_name, &block)
-          # Save current buffer for later
-          @_out_buf, _buf_was = '', @_out_buf
-
-          layout_path = locate_layout(layout_name, self.current_engine)
-
-          extension = File.extname(layout_path)
-          engine = extension[1..-1].to_sym
-
-          # Store last engine for later (could be inside nested renders)
-          self.current_engine, engine_was = engine, self.current_engine
-
-          begin
-            content = if block_given?
-              capture_html(&block)
-            else
-              ''
-            end
-          ensure
-            # Reset stored buffer
-            @_out_buf = _buf_was
-          end
-
-          concat_safe_content render_individual_file(layout_path, @current_locs || {}, @current_opts || {}, self) { content }
-        ensure
-          self.current_engine = engine_was
-        end
-
-        # The currently rendering engine
-        # @return [Symbol, nil]
-        def current_engine
-          @_current_engine ||= nil
-        end
-
-        # The currently rendering engine
-        # @return [Symbol, nil]
-        def current_engine=(v)
-          @_current_engine = v
-        end
-
         # Find a template on disk given a output path
         # @param [String] request_path
         # @param [Hash] options
diff --git a/middleman-core/lib/middleman-core/extension.rb b/middleman-core/lib/middleman-core/extension.rb
index ec02bb8f..78179afe 100644
--- a/middleman-core/lib/middleman-core/extension.rb
+++ b/middleman-core/lib/middleman-core/extension.rb
@@ -20,7 +20,7 @@ module Middleman
       def helpers(*m, &block)
         self.defined_helpers ||= []
 
-        if block
+        if block_given?
           mod = Module.new
           mod.module_eval(&block)
           m = [mod]
@@ -81,8 +81,11 @@ module Middleman
     def app=(app)
       @app = app
 
-      (self.class.defined_helpers || []).each do |m|
-        app.class.send(:include, m)
+      ext = self
+      if ext.respond_to?(:instance_available)
+        @klass.instance_available do
+          ext.instance_available
+        end
       end
     end
 
diff --git a/middleman-core/lib/middleman-core/renderers/haml.rb b/middleman-core/lib/middleman-core/renderers/haml.rb
index 5d68d568..e26ba812 100644
--- a/middleman-core/lib/middleman-core/renderers/haml.rb
+++ b/middleman-core/lib/middleman-core/renderers/haml.rb
@@ -4,24 +4,42 @@ require 'haml'
 module Middleman
   module Renderers
 
+    # Haml precompiles filters before the scope is even available,
+    # thus making it impossible to pass our Middleman instance
+    # in. So we have to resort to heavy hackery :(
+    class HamlTemplate < ::Tilt::HamlTemplate
+      def prepare
+      end
+
+      def evaluate(scope, locals, &block)
+        ::Middleman::Renderers::Haml.last_haml_scope = scope
+
+        options = @options.merge(:filename => eval_file, :line => line)
+        @engine = ::Haml::Engine.new(data, options)
+        output = @engine.render(scope, locals, &block)
+
+        ::Middleman::Renderers::Haml.last_haml_scope = nil
+
+        output
+      end
+    end
+
     # Haml Renderer
     module Haml
+      mattr_accessor :last_haml_scope
 
       # Setup extension
       class << self
         # Once registered
         def registered(app)
+          ::Tilt.prefer(::Middleman::Renderers::HamlTemplate, 'haml')
+
           app.before_configuration do
             template_extensions :haml => :html
           end
 
           # Add haml helpers to context
-          app.send :include, ::Haml::Helpers
-
-          # Setup haml helper paths
-          app.ready do
-            init_haml_helpers
-          end
+          ::Middleman::TemplateContext.send :include, ::Haml::Helpers
         end
         alias :included :registered
       end
diff --git a/middleman-core/lib/middleman-core/renderers/kramdown.rb b/middleman-core/lib/middleman-core/renderers/kramdown.rb
index bccfea76..d5e5757c 100644
--- a/middleman-core/lib/middleman-core/renderers/kramdown.rb
+++ b/middleman-core/lib/middleman-core/renderers/kramdown.rb
@@ -7,6 +7,8 @@ module Middleman
     class KramdownTemplate < ::Tilt::KramdownTemplate
       def evaluate(scope, locals, &block)
         @output ||= begin
+          MiddlemanKramdownHTML.scope = ::Middleman::Renderers::Haml.last_haml_scope || scope
+
           output, warnings = MiddlemanKramdownHTML.convert(@engine.root, @engine.options)
           @engine.warnings.concat(warnings)
           output
@@ -16,13 +18,13 @@ module Middleman
 
     # Custom Kramdown renderer that uses our helpers for images and links
     class MiddlemanKramdownHTML < ::Kramdown::Converter::Html
-      cattr_accessor :middleman_app
+      cattr_accessor :scope
 
       def convert_img(el, indent)
         attrs = el.attr.dup
 
         link = attrs.delete('src')
-        middleman_app.image_tag(link, attrs)
+        scope.image_tag(link, attrs)
       end
 
       def convert_a(el, indent)
@@ -37,7 +39,7 @@ module Middleman
 
         attr = el.attr.dup
         link = attr.delete('href')
-        middleman_app.link_to(content, link, attr)
+        scope.link_to(content, link, attr)
       end
     end
   end
diff --git a/middleman-core/lib/middleman-core/renderers/markdown.rb b/middleman-core/lib/middleman-core/renderers/markdown.rb
index 61e22b17..00fdd8bb 100644
--- a/middleman-core/lib/middleman-core/renderers/markdown.rb
+++ b/middleman-core/lib/middleman-core/renderers/markdown.rb
@@ -30,11 +30,9 @@ module Middleman
               if config[:markdown_engine] == :redcarpet
                 require 'middleman-core/renderers/redcarpet'
                 ::Tilt.prefer(::Middleman::Renderers::RedcarpetTemplate, *markdown_exts)
-                MiddlemanRedcarpetHTML.middleman_app = self
               elsif config[:markdown_engine] == :kramdown
                 require 'middleman-core/renderers/kramdown'
                 ::Tilt.prefer(::Middleman::Renderers::KramdownTemplate, *markdown_exts)
-                MiddlemanKramdownHTML.middleman_app = self
               elsif !config[:markdown_engine].nil?
                 # Map symbols to classes
                 markdown_engine_klass = if config[:markdown_engine].is_a? Symbol
diff --git a/middleman-core/lib/middleman-core/renderers/redcarpet.rb b/middleman-core/lib/middleman-core/renderers/redcarpet.rb
index 79b4f37e..e5ead89e 100644
--- a/middleman-core/lib/middleman-core/renderers/redcarpet.rb
+++ b/middleman-core/lib/middleman-core/renderers/redcarpet.rb
@@ -40,6 +40,14 @@ module Middleman
         renderer.new(render_options)
       end
 
+      def evaluate(scope, locals, &block)
+        @output ||= begin
+          MiddlemanRedcarpetHTML.scope = ::Middleman::Renderers::Haml.last_haml_scope || scope
+
+          @engine.render(data)
+        end
+      end
+
       private
 
         def covert_options_to_aliases!
@@ -51,7 +59,7 @@ module Middleman
 
     # Custom Redcarpet renderer that uses our helpers for images and links
     class MiddlemanRedcarpetHTML < ::Redcarpet::Render::HTML
-      cattr_accessor :middleman_app
+      cattr_accessor :scope
 
       def initialize(options={})
         @local_options = options.dup
@@ -61,7 +69,7 @@ module Middleman
 
       def image(link, title, alt_text)
         if !@local_options[:no_images]
-          middleman_app.image_tag(link, :title => title, :alt => alt_text)
+          scope.image_tag(link, :title => title, :alt => alt_text)
         else
           link_string = link.dup
           link_string << %Q{"#{title}"} if title && title.length > 0 && title != alt_text
@@ -74,7 +82,7 @@ module Middleman
           attributes = { :title => title }
           attributes.merge!( @local_options[:link_attributes] ) if @local_options[:link_attributes]
 
-          middleman_app.link_to(content, link, attributes )
+          scope.link_to(content, link, attributes )
         else
           link_string = link.dup
           link_string << %Q{"#{title}"} if title && title.length > 0 && title != alt_text
diff --git a/middleman-core/lib/middleman-core/renderers/sass.rb b/middleman-core/lib/middleman-core/renderers/sass.rb
index d8c33fd8..f3022696 100644
--- a/middleman-core/lib/middleman-core/renderers/sass.rb
+++ b/middleman-core/lib/middleman-core/renderers/sass.rb
@@ -74,7 +74,7 @@ module Middleman
         def sass_options
           more_opts = { :filename => eval_file, :line => line, :syntax => syntax }
 
-          if @context.is_a?(::Middleman::Application) && file
+          if @context.is_a?(::Middleman::TemplateContext) && file
             location_of_sass_file = @context.source_dir
 
             parts = basename.split('.')
diff --git a/middleman-core/lib/middleman-core/sitemap.rb b/middleman-core/lib/middleman-core/sitemap.rb
index 9bceb950..6d7b6518 100644
--- a/middleman-core/lib/middleman-core/sitemap.rb
+++ b/middleman-core/lib/middleman-core/sitemap.rb
@@ -31,7 +31,7 @@ module Middleman
         }, 'Callbacks that can exclude paths from the sitemap'
 
         # Include instance methods
-        app.send :include, InstanceMethods
+        ::Middleman::TemplateContext.send :include, InstanceMethods
       end
 
     end
diff --git a/middleman-core/lib/middleman-core/template_context.rb b/middleman-core/lib/middleman-core/template_context.rb
new file mode 100644
index 00000000..c2d666d8
--- /dev/null
+++ b/middleman-core/lib/middleman-core/template_context.rb
@@ -0,0 +1,105 @@
+module Middleman
+  class TemplateContext
+    attr_reader :app
+    attr_accessor :current_engine, :current_path
+
+    delegate :config, :logger, :sitemap, :build?, :development?, :data, :extensions, :source_dir, :root, :to => :app
+
+    def initialize(app, locs={}, opts={})
+      @app = app
+      @current_locs = locs
+      @current_opts = opts
+    end
+
+    def save_buffer
+      @_out_buf, _buf_was = '', @_out_buf
+      _buf_was
+    end
+
+    def restore_buffer(_buf_was)
+      @_out_buf = _buf_was
+    end
+
+    # Allow layouts to be wrapped in the contents of other layouts
+    # @param [String, Symbol] layout_name
+    # @return [void]
+    def wrap_layout(layout_name, &block)
+      # Save current buffer for later
+      _buf_was = save_buffer
+
+      layout_path = @app.locate_layout(layout_name, self.current_engine)
+
+      extension = File.extname(layout_path)
+      engine = extension[1..-1].to_sym
+
+      # Store last engine for later (could be inside nested renders)
+      self.current_engine, engine_was = engine, self.current_engine
+
+      begin
+        content = if block_given?
+          capture_html(&block)
+        else
+          ''
+        end
+      ensure
+        # Reset stored buffer
+        restore_buffer(_buf_was)
+      end
+
+      concat_safe_content @app.render_individual_file(layout_path, @current_locs || {}, @current_opts || {}, self) { content }
+    ensure
+      self.current_engine = engine_was
+    end
+
+    # Sinatra/Padrino compatible render method signature referenced by some view
+    # helpers. Especially partials.
+    #
+    # @param [String, Symbol] engine
+    # @param [String, Symbol] data
+    # @param [Hash] options
+    # @return [String]
+    def render(engine, data, options={}, &block)
+      data = data.to_s
+
+      locals = options[:locals]
+
+      found_partial = false
+      engine        = nil
+
+      # If the path is known to the sitemap
+      if resource = sitemap.find_resource_by_path(current_path)
+        current_dir = File.dirname(resource.source_file)
+        engine = File.extname(resource.source_file)[1..-1].to_sym
+
+        # Look for partials relative to the current path
+        relative_dir = File.join(current_dir.sub(%r{^#{Regexp.escape(self.source_dir)}/?}, ''), data)
+
+        # Try to use the current engine first
+        found_partial, found_engine = @app.resolve_template(relative_dir, :preferred_engine => engine, :try_without_underscore => true)
+
+        # Fall back to any engine available
+        if !found_partial
+          found_partial, found_engine = @app.resolve_template(relative_dir, :try_without_underscore => true)
+        end
+      end
+
+      # Look in the partials_dir for the partial with the current engine
+      partials_path = File.join(config[:partials_dir], data)
+      if !found_partial && !engine.nil?
+        found_partial, found_engine = @app.resolve_template(partials_path, :preferred_engine => engine, :try_without_underscore => true)
+      end
+
+      # Look in the root with any engine
+      if !found_partial
+        found_partial, found_engine = @app.resolve_template(partials_path, :try_without_underscore => true)
+      end
+
+      # Render the partial if found, otherwide throw exception
+      if found_partial
+        @app.render_individual_file(found_partial, locals, options, self, &block)
+      else
+        raise ::Middleman::CoreExtensions::Rendering::TemplateNotFound, "Could not locate partial: #{data}"
+      end
+    end
+  end
+end
diff --git a/middleman-core/lib/middleman-more/core_extensions/default_helpers.rb b/middleman-core/lib/middleman-more/core_extensions/default_helpers.rb
index 64b11911..d9c70aa5 100644
--- a/middleman-core/lib/middleman-more/core_extensions/default_helpers.rb
+++ b/middleman-core/lib/middleman-more/core_extensions/default_helpers.rb
@@ -21,15 +21,15 @@ class Middleman::CoreExtensions::DefaultHelpers < ::Middleman::Extension
 
     require 'active_support/core_ext/object/to_query'
 
-    app.helpers ::Padrino::Helpers::OutputHelpers
-    app.helpers ::Padrino::Helpers::TagHelpers
-    app.helpers ::Padrino::Helpers::AssetTagHelpers
-    app.helpers ::Padrino::Helpers::FormHelpers
-    app.helpers ::Padrino::Helpers::FormatHelpers
-    app.helpers ::Padrino::Helpers::RenderHelpers
-    app.helpers ::Padrino::Helpers::NumberHelpers
-    # app.helpers ::Padrino::Helpers::TranslationHelpers
-    app.helpers ::Padrino::Helpers::Breadcrumbs
+    ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::OutputHelpers
+    ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::TagHelpers
+    ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::AssetTagHelpers
+    ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::FormHelpers
+    ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::FormatHelpers
+    ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::RenderHelpers
+    ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::NumberHelpers
+    # ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::TranslationHelpers
+    ::Middleman::TemplateContext.send :include, ::Padrino::Helpers::Breadcrumbs
 
     app.config.define_setting :relative_links, false, 'Whether to generate relative links instead of absolute ones'
   end
@@ -39,6 +39,7 @@ class Middleman::CoreExtensions::DefaultHelpers < ::Middleman::Extension
 
     # Make all block content html_safe
     def content_tag(name, content = nil, options = nil, &block)
+      # safe_content_tag(name, content, options, &block)
       if block_given?
         options = content if content.is_a?(Hash)
         content = capture_html(&block)
@@ -61,17 +62,23 @@ class Middleman::CoreExtensions::DefaultHelpers < ::Middleman::Extension
     def capture_html(*args, &block)
       handler = auto_find_proper_handler(&block)
       captured_block, captured_html = nil, ''
-      if handler && handler.is_type? && handler.block_is_type?(block)
+
+      if handler && handler.block_is_type?(block)
         captured_html, captured_block = handler.capture_from_template(*args, &block)
       end
+
       # invoking the block directly if there was no template
-      captured_html = block_given? && ( captured_block || block.call(*args) )  if captured_html.blank?
+      captured_html = block_given? && ( captured_block || block.call(*args) ) if captured_html.blank?
       captured_html
     end
 
     def auto_find_proper_handler(&block)
-      engine = block_given? ? File.extname(block.source_location[0])[1..-1].to_sym : current_engine
-      ::Padrino::Helpers::OutputHelpers.handlers.map { |h| h.new(self) }.find { |h| h.engines.include?(engine) && h.is_type? }
+      if block_given?
+        engine = File.extname(block.source_location[0])[1..-1].to_sym
+        ::Padrino::Helpers::OutputHelpers.handlers.map { |h| h.new(self) }.find { |h| h.engines.include?(engine) && h.block_is_type?(block) }
+      else
+        find_proper_handler
+      end
     end
 
     # Disable Padrino cache buster
@@ -197,7 +204,7 @@ class Middleman::CoreExtensions::DefaultHelpers < ::Middleman::Extension
       options_with_resource = options.dup
       options_with_resource[:current_resource] ||= current_resource
 
-      ::Middleman::Util.url_for(self, path_or_resource, options_with_resource)
+      ::Middleman::Util.url_for(app, path_or_resource, options_with_resource)
     end
 
     # Overload the regular link_to to be sitemap-aware - if you
diff --git a/middleman-core/lib/middleman-more/extensions/gzip.rb b/middleman-core/lib/middleman-more/extensions/gzip.rb
index 6ca5e6d1..89ea38ed 100644
--- a/middleman-core/lib/middleman-more/extensions/gzip.rb
+++ b/middleman-core/lib/middleman-more/extensions/gzip.rb
@@ -12,6 +12,10 @@
 class Middleman::Extensions::Gzip < ::Middleman::Extension
   option :exts, %w(.js .css .html .htm), 'File extensions to Gzip when building.'
 
+  class NumberHelpers
+    include ::Padrino::Helpers::NumberHelpers
+  end
+
   def initialize(app, options_hash={})
     super
 
@@ -57,11 +61,11 @@ class Middleman::Extensions::Gzip < ::Middleman::Extension
       if output_filename
         total_savings += (old_size - new_size)
         size_change_word = (old_size - new_size) > 0 ? 'smaller' : 'larger'
-        builder.say_status :gzip, "#{output_filename} (#{app.number_to_human_size((old_size - new_size).abs)} #{size_change_word})"
+        builder.say_status :gzip, "#{output_filename} (#{NumberHelpers.new.number_to_human_size((old_size - new_size).abs)} #{size_change_word})"
       end
     end
 
-    builder.say_status :gzip, "Total gzip savings: #{app.number_to_human_size(total_savings)}", :blue
+    builder.say_status :gzip, "Total gzip savings: #{NumberHelpers.new.number_to_human_size(total_savings)}", :blue
     I18n.locale = old_locale
   end