fix if tag parsing with expressions starting with and/or

lib/liquid/tags/if.rb

@@ -14,7 +14,7 @@ module Liquid
   class If < Block
     SyntaxHelp = "Syntax Error in tag 'if' - Valid syntax: if [expression]"
     Syntax = /(#{QuotedFragment})\s*([=!<>a-z_]+)?\s*(#{QuotedFragment})?/
-    ExpressionsAndOperators = /(?:and|or|(?:\s*(?!\b(?:and|or)\b)(?:#{QuotedFragment}|\S+)\s*)+)/
+    ExpressionsAndOperators = /(?:\b(?:and|or)\b|(?:\s*(?!\b(?:and|or)\b)(?:#{QuotedFragment}|\S+)\s*)+)/
     
     def initialize(tag_name, markup, tokens)    
     

test/if_else_test.rb

@@ -44,6 +44,20 @@ class IfElseTest < Test::Unit::TestCase
     end
   end
   
+  def test_comparison_of_expressions_starting_with_and_or_or
+    assigns = {'order' => {'items_count' => 0}, 'android' => {'name' => 'Roy'}}
+    assert_nothing_raised do
+      assert_template_result( "YES",
+                              "{% if android.name == 'Roy' %}YES{% endif %}",
+                              assigns)
+    end
+    assert_nothing_raised do
+      assert_template_result( "YES",
+                              "{% if order.items_count == 0 %}YES{% endif %}",
+                              assigns)
+    end
+  end
+  
   def test_if_and
     assert_template_result(' YES ','{% if true and true %} YES {% endif %}')    
     assert_template_result('','{% if false and true %} YES {% endif %}')