Allow liquid tag inside liquid tag

lib/liquid/block_body.rb

@@ -45,6 +45,9 @@ module Liquid
           end
           tag_name = Regexp.last_match(1)
           markup   = Regexp.last_match(2)
+          if tag_name == "liquid"
+            next
+          end
           unless (tag = registered_tags[tag_name])
             # end parsing if we reach an unknown tag and let the caller decide
             # determine how to proceed

test/integration/tags/liquid_tag_test.rb

@@ -113,4 +113,15 @@ class LiquidTagTest < Minitest::Test
       {% raw %}{% liquid echo 'test' %}{% endraw %}
     LIQUID
   end
+
+  def test_nested_liquid_tags
+    assert_template_result('good', <<~LIQUID)
+      {%- liquid
+        liquid
+          if true
+            echo "good"
+          endif
+      -%}
+    LIQUID
+  end
 end