A better fix for "and"/"or" in strings

(now with less side effects)

lib/liquid/condition.rb

@@ -21,10 +21,6 @@ module Liquid
     def self.operators
       @@operators
     end
-    
-    def self.operator_regexp
-      Regexp.new(@@operators.keys.sort_by(&:length).reverse.map {|k| Regexp.escape(k)}.join('|'))
-    end
 
     attr_reader :attachment
     attr_accessor :left, :operator, :right

lib/liquid/tags/if.rb

@@ -13,8 +13,8 @@ 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|#{QuotedFragment}\s*(?:(?!and|or)(?:[=!<>a-z_]+)\s*#{QuotedFragment})?/
+    Syntax = /(#{QuotedFragment})\s*([=!<>a-z_]+)?\s*(#{QuotedFragment})?/
+    ExpressionsAndOperators = /(?:and|or|(?:\s*(?!\b(?:and|or)\b)(?:#{QuotedFragment}|\S+)\s*)+)/
     
     def initialize(tag_name, markup, tokens)    
     
@@ -51,9 +51,7 @@ module Liquid
         ElseCondition.new
       else        
         
-        # expressions = markup.split(/\b(and|or)\b/).reverse
-        
-        expressions = markup.scan(ExpressionsAndOperators).flatten.compact.reverse
+        expressions = markup.scan(ExpressionsAndOperators).reverse
         raise(SyntaxError, SyntaxHelp) unless expressions.shift =~ Syntax 
 
         condition = Condition.new($1, $2, $3)               

test/parsing_quirks_test.rb

@@ -38,4 +38,17 @@ class ParsingQuirksTest < Test::Unit::TestCase
     end
   end
   
+  def test_meaningless_parens
+    assigns = {'b' => 'bar', 'c' => 'baz'}
+    markup = "a == 'foo' or (b == 'bar' and c == 'baz') or false"
+    assert_template_result(' YES ',"{% if #{markup} %} YES {% endif %}", assigns)
+  end
+  
+  def test_unexpected_characters_silently_eat_logic
+    markup = "true && false"
+    assert_template_result(' YES ',"{% if #{markup} %} YES {% endif %}")
+    markup = "false || true"
+    assert_template_result('',"{% if #{markup} %} YES {% endif %}")
+  end
+  
 end

test/statements_test.rb

@@ -17,31 +17,31 @@ class StatementsTest < Test::Unit::TestCase
     assert_equal expected, Template.parse(text).render
   end
 
-  def test_zero_gt_zero
+  def test_true_lq_true
     text = %| {% if 0 > 0 %} true {% else %} false {% endif %} |
     expected = %|  false  |
     assert_equal expected, Template.parse(text).render
   end
 
-  def test_one_gt_zero
+  def test_one_lq_zero
     text = %| {% if 1 > 0 %} true {% else %} false {% endif %} |
     expected = %|  true  |
     assert_equal expected, Template.parse(text).render
   end
 
-  def test_zero_lt_one
+  def test_zero_lq_one
     text = %| {% if 0 < 1 %} true {% else %} false {% endif %} |
     expected = %|  true  |
     assert_equal expected, Template.parse(text).render
   end
 
-  def test_zero_lt_or_equal_zero
+  def test_zero_lq_or_equal_one
     text = %| {% if 0 <= 0 %} true {% else %} false {% endif %} |
     expected = %|  true  |
     assert_equal expected, Template.parse(text).render
   end
 
-  def test_zero_lt_or_equal_zero_involving_nil
+  def test_zero_lq_or_equal_one_involving_nil
     text = %| {% if null <= 0 %} true {% else %} false {% endif %} |
     expected = %|  false  |
     assert_equal expected, Template.parse(text).render
@@ -52,7 +52,7 @@ class StatementsTest < Test::Unit::TestCase
     assert_equal expected, Template.parse(text).render
   end
 
-  def test_zero_gt_or_equal_zero
+  def test_zero_lqq_or_equal_one
     text = %| {% if 0 >= 0 %} true {% else %} false {% endif %} |
     expected = %|  true  |
     assert_equal expected, Template.parse(text).render