From 6ce4ec1011c35dd29ba68bf94dd2686e19e95604 Mon Sep 17 00:00:00 2001
From: Dylan Thacker-Smith <dylan.smith@shopify.com>
Date: Tue, 25 Oct 2022 10:21:03 -0400
Subject: [PATCH] tablerow: Avoid accidental special case for constant nil cols
 (#1644)

It should behave the same as an expression that evaluates to nil
---
 lib/liquid/tags/table_row.rb            |  2 +-
 test/integration/tags/table_row_test.rb | 14 ++++++++++++++
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/lib/liquid/tags/table_row.rb b/lib/liquid/tags/table_row.rb
index 5371f70a..87f3e096 100644
--- a/lib/liquid/tags/table_row.rb
+++ b/lib/liquid/tags/table_row.rb
@@ -51,7 +51,7 @@ module Liquid
       collection = Utils.slice_collection(collection, from, to)
       length     = collection.length
 
-      cols = @attributes['cols'].nil? ? length : context.evaluate(@attributes['cols']).to_i
+      cols = @attributes.key?('cols') ? context.evaluate(@attributes['cols']).to_i : length
 
       output << "<tr class=\"row1\">\n"
       context.stack do
diff --git a/test/integration/tags/table_row_test.rb b/test/integration/tags/table_row_test.rb
index 1f6edda4..8556ed2d 100644
--- a/test/integration/tags/table_row_test.rb
+++ b/test/integration/tags/table_row_test.rb
@@ -66,6 +66,20 @@ class TableRowTest < Minitest::Test
       { 'characters' => '' })
   end
 
+  def test_cols_nil_constant_same_as_evaluated_nil_expression
+    expect = "<tr class=\"row1\">\n" \
+      "<td class=\"col1\">false</td>" \
+      "<td class=\"col2\">false</td>" \
+      "</tr>\n"
+
+    assert_template_result(expect,
+      "{% tablerow i in (1..2) cols:nil %}{{ tablerowloop.col_last }}{% endtablerow %}")
+
+    assert_template_result(expect,
+      "{% tablerow i in (1..2) cols:var %}{{ tablerowloop.col_last }}{% endtablerow %}",
+      { "var" => nil })
+  end
+
   def test_tablerow_loop_drop_attributes
     template = <<~LIQUID.chomp
       {% tablerow i in (1...2) %}