Merge branch 'master' into liquid-utf8

Conflicts:
	lib/liquid/variable.rb

lib/liquid/context.rb

@@ -39,6 +39,7 @@ module Liquid
 
       filters.each do |f|
         raise ArgumentError, "Expected module but got: #{f.class}" unless f.is_a?(Module)
+        Strainer.add_known_filter(f)
         strainer.extend(f)
       end
     end
@@ -71,11 +72,7 @@ module Liquid
     end
 
     def invoke(method, *args)
-      if strainer.respond_to?(method)
-        strainer.__send__(method, *args)
-      else
-        args.first
-      end
+      strainer.invoke(method, *args)
     end
 
     # Push new local scope on the stack. use <tt>Context#stack</tt> instead

lib/liquid/drop.rb

@@ -1,3 +1,5 @@
+require 'set'
+
 module Liquid
 
   # A drop in liquid is a class which allows you to export DOM like things to liquid.
@@ -31,8 +33,8 @@ module Liquid
 
     # called by liquid to invoke a drop
     def invoke_drop(method_or_key)
-      if method_or_key && method_or_key != EMPTY_STRING && self.class.public_method_defined?(method_or_key.to_s.to_sym)
-        send(method_or_key.to_s.to_sym)
+      if method_or_key && method_or_key != EMPTY_STRING && self.class.invokable?(method_or_key)
+        send(method_or_key)
       else
         before_method(method_or_key)
       end
@@ -47,5 +49,13 @@ module Liquid
     end
 
     alias :[] :invoke_drop
+
+    private
+
+    # 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))
+      @invokable_methods.include?(method_name.to_s)
+    end
   end
 end

lib/liquid/strainer.rb

@@ -2,24 +2,15 @@ require 'set'
 
 module Liquid
 
-  parent_object = if defined? BlankObject
-    BlankObject
-  else
-    Object
-  end
-
   # Strainer is the parent class for the filters system.
-  # New filters are mixed into the strainer class which is then instanciated for each liquid template render run.
+  # New filters are mixed into the strainer class which is then instantiated for each liquid template render run.
   #
-  # One of the strainer's responsibilities is to keep malicious method calls out
-  class Strainer < parent_object #:nodoc:
-    INTERNAL_METHOD = /^__/
-    @@required_methods = Set.new([:__id__, :__send__, :respond_to?, :kind_of?, :extend, :methods, :singleton_methods, :class, :object_id])
-
-    # Ruby 1.9.2 introduces Object#respond_to_missing?, which is invoked by Object#respond_to?
-    @@required_methods << :respond_to_missing? if Object.respond_to? :respond_to_missing?
-
+  # The Strainer only allows method calls defined in filters given to it via Strainer.global_filter,
+  # Context#add_filters or Template.register_filter
+  class Strainer #:nodoc:
     @@filters = {}
+    @@known_filters = Set.new
+    @@known_methods = Set.new
 
     def initialize(context)
       @context = context
@@ -27,28 +18,36 @@ module Liquid
 
     def self.global_filter(filter)
       raise ArgumentError, "Passed filter is not a module" unless filter.is_a?(Module)
+      add_known_filter(filter)
       @@filters[filter.name] = filter
     end
 
+    def self.add_known_filter(filter)
+      unless @@known_filters.include?(filter)
+        @@method_blacklist ||= Set.new(Strainer.instance_methods.map(&:to_s))
+        new_methods = filter.instance_methods.map(&:to_s)
+        new_methods.reject!{ |m| @@method_blacklist.include?(m) }
+        @@known_methods.merge(new_methods)
+        @@known_filters.add(filter)
+      end
+    end
+
     def self.create(context)
       strainer = Strainer.new(context)
       @@filters.each { |k,m| strainer.extend(m) }
       strainer
     end
 
-    def respond_to?(method, include_private = false)
-      method_name = method.to_s
-      return false if method_name =~ INTERNAL_METHOD
-      return false if @@required_methods.include?(method_name)
-      super
+    def invoke(method, *args)
+      if invokable?(method)
+        send(method, *args)
+      else
+        args.first
+      end
     end
 
-    # remove all standard methods from the bucket so circumvent security
-    # problems
-    instance_methods.each do |m|
-      unless @@required_methods.include?(m.to_sym)
-        undef_method m
-      end
+    def invokable?(method)
+      @@known_methods.include?(method.to_s) && respond_to?(method)
     end
   end
 end

lib/liquid/variable.rb

@@ -23,10 +23,10 @@ module Liquid
         if match[2].match(/#{FilterSeparator}\s*(.*)/o)
           filters = Regexp.last_match(1).scan(FilterParser)
           filters.each do |f|
-            if matches = f.match(/\s*(#{WordRegex}+)/o)
+            if matches = f.match(/\s*(#{WordRegex}+)(?:\s*#{FilterArgumentSeparator}(.*))?/)
               filtername = matches[1]
-              filterargs = f.scan(/(?:#{FilterArgumentSeparator}|#{ArgumentSeparator})\s*(#{QuotedFragment})/o).flatten
-              @filters << [filtername.to_sym, filterargs]
+              filterargs = matches[2].to_s.scan(/(?:\A|#{ArgumentSeparator})\s*((?:\w+\s*\:\s*)?#{QuotedFragment})/o).flatten
+              @filters << [filtername, filterargs]
             end
           end
         end
@@ -36,9 +36,16 @@ module Liquid
     def render(context)
       return '' if @name.nil?
       @filters.inject(context[@name]) do |output, filter|
-        filterargs = filter[1].to_a.collect do |a|
-          context[a]
+        filterargs = []
+        keyword_args = {}
+        filter[1].to_a.each do |a|
+          if matches = a.match(/\A#{TagAttributes}\z/o)
+            keyword_args[matches[1]] = context[matches[2]]
+          else
+            filterargs << context[a]
+          end
         end
+        filterargs << keyword_args unless keyword_args.empty?
         begin
           output = context.invoke(filter[0], output, *filterargs)
         rescue FilterNotFound