Prevent an internal error in include tag from non-string template_name

which would otherwise happen on `template_name.split('/')`

lib/liquid/tags/include.rb

@@ -52,7 +52,7 @@ module Liquid
 
     def render_to_output_buffer(context, output)
       template_name = context.evaluate(@template_name_expr)
-      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name
+      raise ArgumentError, options[:locale].t("errors.argument.include") unless template_name.is_a?(String)
 
       partial = PartialCache.load(
         template_name,

test/integration/tags/include_tag_test.rb

@@ -249,6 +249,11 @@ class IncludeTagTest < Minitest::Test
       "{% include nil %}", render_errors: true)
   end
 
+  def test_render_raise_argument_error_when_template_is_not_a_string
+    assert_template_result("Liquid error (line 1): Argument error in tag 'include' - Illegal template name",
+      "{% include 123 %}", render_errors: true)
+  end
+
   def test_including_via_variable_value
     assert_template_result("from TestFileSystem", "{% assign page = 'pick_a_source' %}{% include page %}",
       partials: { "pick_a_source" => "from TestFileSystem" })