Fix tablerow block to work with collection names in quoted syntax.

* Allows e.g. {% tablerow product in collections['frontpage'] %} instead of only collections.frontpage

lib/liquid/htmltags.rb

@@ -1,6 +1,6 @@
 module Liquid
   class TableRow < Block
-    Syntax = /(\w+)\s+in\s+(#{VariableSignature}+)/
+    Syntax = /(\w+)\s+in\s+(#{QuotedFragment}+)/
 
     def initialize(tag_name, markup, tokens)
       if markup =~ Syntax

test/liquid/tags/html_tag_test.rb

@@ -26,4 +26,11 @@ class HtmlTagTest < Test::Unit::TestCase
                            '{% tablerow n in numbers cols:2%}{{tablerowloop.col}}{% endtablerow %}',
                            'numbers' => [1,2,3,4,5,6])
   end
+
+  def test_quoted_fragment
+    assert_template_result("<tr class=\"row1\">\n<td class=\"col1\"> 1 </td><td class=\"col2\"> 2 </td><td class=\"col3\"> 3 </td></tr>\n<tr class=\"row2\"><td class=\"col1\"> 4 </td><td class=\"col2\"> 5 </td><td class=\"col3\"> 6 </td></tr>\n",
+                           "{% tablerow n in collections['frontpage'] cols:3%} {{n}} {% endtablerow %}",
+                           'collections' => {'frontpage' => [1,2,3,4,5,6]})
+    
+  end
 end # HtmlTagTest