diff --git a/History.md b/History.md
index 3312c0a..1dc8ad0 100644
--- a/History.md
+++ b/History.md
@@ -6,6 +6,11 @@ The following releases will only be tested against Ruby 1.9 and Ruby 2.0 and are
 ## 2.6.0 / Master branch (not yet released)
 
 * ...
+* Make sort filter work on enumerable drops, see #239 [Florian Weingarten, fw42]
+* Fix clashing method names in enumerable drops, see #238 [Florian Weingarten, fw42]
+* Make map filter work on enumerable drops, see #233 [Florian Weingarten, fw42]
+* Fix security issue with map filter, see #230, #232, #234, #237 [Florian Weingarten, fw42]
+* Improved whitespace stripping for blank blocks, related to #216 [Florian Weingarten, fw42]
 * Bugfix for #106: fix example servlet [gnowoel]
 * Bugfix for #97: strip_html filter supports multi-line tags [Jo Liss, joliss]
 * Bugfix for #114: strip_html filter supports style tags [James Allardice, jamesallardice]
diff --git a/README.md b/README.md
index 695e9bb..481f18e 100644
--- a/README.md
+++ b/README.md
@@ -4,6 +4,7 @@
 * [Version history](History.md)
 * [Liquid documentation from Shopify](http://docs.shopify.com/themes/liquid-basics)
 * [Liquid Wiki from Shopify](http://wiki.shopify.com/Liquid)
+* [Liquid Wiki at GitHub](https://github.com/Shopify/liquid/wiki)
 * [Website](http://liquidmarkup.org/)
 
 ## Introduction
diff --git a/lib/liquid/drop.rb b/lib/liquid/drop.rb
index 88adb6b..f1bf48a 100644
--- a/lib/liquid/drop.rb
+++ b/lib/liquid/drop.rb
@@ -44,6 +44,10 @@ module Liquid
       true
     end
 
+    def inspect
+      self.class.to_s
+    end
+
     def to_liquid
       self
     end
@@ -54,7 +58,16 @@ module Liquid
 
     # Check for method existence without invoking respond_to?, which creates symbols
     def self.invokable?(method_name)
-      @invokable_methods ||= Set.new((public_instance_methods - Liquid::Drop.public_instance_methods).map(&:to_s))
+      unless @invokable_methods
+        # Ruby 1.8 compatibility: call to_s on method names (which are strings in 1.8, but already symbols in 1.9)
+        blacklist = (Liquid::Drop.public_instance_methods + [:each]).map(&:to_s)
+        if include?(Enumerable)
+          blacklist += Enumerable.public_instance_methods.map(&:to_s)
+          blacklist -= [:sort, :count, :first, :min, :max, :include?].map(&:to_s)
+        end
+        whitelist = [:to_liquid] + (public_instance_methods.map(&:to_s) - blacklist.map(&:to_s))
+        @invokable_methods = Set.new(whitelist.map(&:to_s))
+      end
       @invokable_methods.include?(method_name.to_s)
     end
   end
diff --git a/lib/liquid/standardfilters.rb b/lib/liquid/standardfilters.rb
index 77bb945..b7f6418 100644
--- a/lib/liquid/standardfilters.rb
+++ b/lib/liquid/standardfilters.rb
@@ -81,7 +81,7 @@ module Liquid
     # Sort elements of the array
     # provide optional property with which to sort an array of hashes or drops
     def sort(input, property = nil)
-      ary = [input].flatten
+      ary = flatten_if_necessary(input)
       if property.nil?
         ary.sort
       elsif ary.first.respond_to?('[]') and !ary.first[property].nil?
@@ -99,11 +99,14 @@ module Liquid
 
     # map/collect on a given property
     def map(input, property)
-      ary = [input].flatten
-      if ary.first.respond_to?('[]') and !ary.first[property].nil?
-        ary.map {|e| e[property] }
-      elsif ary.first.respond_to?(property)
-        ary.map {|e| e.send(property) }
+      flatten_if_necessary(input).map do |e|
+        e = e.call if e.is_a?(Proc)
+
+        if property == "to_liquid"
+          e
+        elsif e.respond_to?(:[])
+          e[property]
+        end
       end
     end
 
@@ -244,6 +247,17 @@ module Liquid
 
     private
 
+    def flatten_if_necessary(input)
+      ary = if input.is_a?(Array)
+        input.flatten
+      elsif input.kind_of?(Enumerable)
+        input
+      else
+        [input].flatten
+      end
+      ary.map{ |e| e.respond_to?(:to_liquid) ? e.to_liquid : e }
+    end
+
     def to_number(obj)
       case obj
       when Float
diff --git a/liquid.gemspec b/liquid.gemspec
index 0e909ca..e4b401e 100644
--- a/liquid.gemspec
+++ b/liquid.gemspec
@@ -12,6 +12,7 @@ Gem::Specification.new do |s|
   s.authors     = ["Tobias Luetke"]
   s.email       = ["tobi@leetsoft.com"]
   s.homepage    = "http://www.liquidmarkup.org"
+  s.license     = "MIT"
   #s.description = "A secure, non-evaling end user template engine with aesthetic markup."
 
   s.required_rubygems_version = ">= 1.3.7"
diff --git a/test/liquid/drop_test.rb b/test/liquid/drop_test.rb
index 7819f64..d8d02d9 100644
--- a/test/liquid/drop_test.rb
+++ b/test/liquid/drop_test.rb
@@ -55,11 +55,44 @@ class ProductDrop < Liquid::Drop
 end
 
 class EnumerableDrop < Liquid::Drop
+  def before_method(method)
+    method
+  end
 
   def size
     3
   end
 
+  def first
+    1
+  end
+
+  def count
+    3
+  end
+
+  def min
+    1
+  end
+
+  def max
+    3
+  end
+
+  def each
+    yield 1
+    yield 2
+    yield 3
+  end
+end
+
+class RealEnumerableDrop < Liquid::Drop
+  include Enumerable
+
+  def before_method(method)
+    method
+  end
+
   def each
     yield 1
     yield 2
@@ -71,23 +104,34 @@ class DropsTest < Test::Unit::TestCase
   include Liquid
 
   def test_product_drop
-
     assert_nothing_raised do
       tpl = Liquid::Template.parse( '  '  )
       tpl.render('product' => ProductDrop.new)
     end
   end
 
+  def test_drop_does_only_respond_to_whitelisted_methods
+    assert_equal "", Liquid::Template.parse("{{ product.inspect }}").render('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse("{{ product.pretty_inspect }}").render('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse("{{ product.whatever }}").render('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse('{{ product | map: "inspect" }}').render('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse('{{ product | map: "pretty_inspect" }}').render('product' => ProductDrop.new)
+    assert_equal "", Liquid::Template.parse('{{ product | map: "whatever" }}').render('product' => ProductDrop.new)
+  end
+
+  def test_drops_respond_to_to_liquid
+    assert_equal "text1", Liquid::Template.parse("{{ product.to_liquid.texts.text }}").render('product' => ProductDrop.new)
+    assert_equal "text1", Liquid::Template.parse('{{ product | map: "to_liquid" | map: "texts" | map: "text" }}').render('product' => ProductDrop.new)
+  end
+
   def test_text_drop
     output = Liquid::Template.parse( ' {{ product.texts.text }} '  ).render('product' => ProductDrop.new)
     assert_equal ' text1 ', output
-
   end
 
   def test_unknown_method
     output = Liquid::Template.parse( ' {{ product.catchall.unknown }} '  ).render('product' => ProductDrop.new)
     assert_equal ' method: unknown ', output
-
   end
 
   def test_integer_argument_drop
@@ -159,6 +203,33 @@ class DropsTest < Test::Unit::TestCase
     assert_equal '3', Liquid::Template.parse( '{{collection.size}}').render('collection' => EnumerableDrop.new)
   end
 
+  def test_enumerable_drop_will_invoke_before_method_for_clashing_method_names
+    ["select", "each", "map", "cycle"].each do |method|
+      assert_equal method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render('collection' => EnumerableDrop.new)
+      assert_equal method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render('collection' => EnumerableDrop.new)
+      assert_equal method.to_s, Liquid::Template.parse("{{collection.#{method}}}").render('collection' => RealEnumerableDrop.new)
+      assert_equal method.to_s, Liquid::Template.parse("{{collection[\"#{method}\"]}}").render('collection' => RealEnumerableDrop.new)
+    end
+  end
+
+  def test_some_enumerable_methods_still_get_invoked
+    [ :count, :max ].each do |method|
+      assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render('collection' => RealEnumerableDrop.new)
+      assert_equal "3", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render('collection' => RealEnumerableDrop.new)
+      assert_equal "3", Liquid::Template.parse("{{collection.#{method}}}").render('collection' => EnumerableDrop.new)
+      assert_equal "3", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render('collection' => EnumerableDrop.new)
+    end
+
+    assert_equal "yes", Liquid::Template.parse("{% if collection contains 3 %}yes{% endif %}").render('collection' => RealEnumerableDrop.new)
+
+    [ :min, :first ].each do |method|
+      assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render('collection' => RealEnumerableDrop.new)
+      assert_equal "1", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render('collection' => RealEnumerableDrop.new)
+      assert_equal "1", Liquid::Template.parse("{{collection.#{method}}}").render('collection' => EnumerableDrop.new)
+      assert_equal "1", Liquid::Template.parse("{{collection[\"#{method}\"]}}").render('collection' => EnumerableDrop.new)
+    end
+  end
+
   def test_empty_string_value_access
     assert_equal '', Liquid::Template.parse('{{ product[value] }}').render('product' => ProductDrop.new, 'value' => '')
   end
diff --git a/test/liquid/standard_filter_test.rb b/test/liquid/standard_filter_test.rb
index f971e72..b317b68 100644
--- a/test/liquid/standard_filter_test.rb
+++ b/test/liquid/standard_filter_test.rb
@@ -6,6 +6,39 @@ class Filters
   include Liquid::StandardFilters
 end
 
+class TestThing
+  def initialize
+    @foo = 0
+  end
+
+  def to_s
+    "woot: #{@foo}"
+  end
+
+  def [](whatever)
+    to_s
+  end
+
+  def to_liquid
+    @foo += 1
+    self
+  end
+end
+
+class TestDrop < Liquid::Drop
+  def test
+    "testfoo"
+  end
+end
+
+class TestEnumerable < Liquid::Drop
+  include Enumerable
+
+  def each(&block)
+    [ { "foo" => 1, "bar" => 2 }, { "foo" => 2, "bar" => 1 }, { "foo" => 3, "bar" => 3 } ].each(&block)
+  end
+end
+
 class StandardFiltersTest < Test::Unit::TestCase
   include Liquid
 
@@ -97,6 +130,36 @@ class StandardFiltersTest < Test::Unit::TestCase
       'ary' => [{'foo' => {'bar' => 'a'}}, {'foo' => {'bar' => 'b'}}, {'foo' => {'bar' => 'c'}}]
   end
 
+  def test_map_doesnt_call_arbitrary_stuff
+    assert_equal "", Liquid::Template.parse('{{ "foo" | map: "__id__" }}').render
+    assert_equal "", Liquid::Template.parse('{{ "foo" | map: "inspect" }}').render
+  end
+
+  def test_map_calls_to_liquid
+    t = TestThing.new
+    assert_equal "woot: 1", Liquid::Template.parse('{{ foo | map: "whatever" }}').render("foo" => [t])
+  end
+
+  def test_sort_calls_to_liquid
+    t = TestThing.new
+    assert_equal "woot: 1", Liquid::Template.parse('{{ foo | sort: "whatever" }}').render("foo" => [t])
+  end
+
+  def test_map_over_proc
+    drop = TestDrop.new
+    p = Proc.new{ drop }
+    templ = '{{ procs | map: "test" }}'
+    assert_equal "testfoo", Liquid::Template.parse(templ).render("procs" => [p])
+  end
+
+  def test_map_works_on_enumerables
+    assert_equal "123", Liquid::Template.parse('{{ foo | map: "foo" }}').render!("foo" => TestEnumerable.new)
+  end
+
+  def test_sort_works_on_enumerables
+    assert_equal "213", Liquid::Template.parse('{{ foo | sort: "bar" | map: "foo" }}').render!("foo" => TestEnumerable.new)
+  end
+
   def test_date
     assert_equal 'May', @filters.date(Time.parse("2006-05-05 10:00:00"), "%B")
     assert_equal 'June', @filters.date(Time.parse("2006-06-05 10:00:00"), "%B")