Fix default rendered format problem when calling render method withou…

…t :content_type option. Closes #11393.

actionview/CHANGELOG.md

@@ -1,3 +1,8 @@
+*   Fix default rendered format problem when calling `render` without :content_type option.
+    It should return :html. Fix #11393.
+
+    *Gleb Mazovetskiy* *Oleg* *kennyj*
+
 *   Fix `link_to` with block and url hashes.
 
     Before:

actionview/lib/action_view/renderer/template_renderer.rb

@@ -11,7 +11,7 @@ def render(context, options)
       prepend_formats(template.formats)
 
       unless context.rendered_format
-        context.rendered_format = template.formats.first || formats.last
+        context.rendered_format = template.formats.first || formats.first
       end
 
       render_template(template, options[:layout], options[:locals])

actionview/test/template/render_test.rb

@@ -41,6 +41,11 @@ def test_render_template_with_format
     assert_match "<error>No Comment</error>", @view.render(:template => "comments/empty", :formats => [:xml])
   end
 
+  def test_rendered_format_without_format
+    @view.render(:inline => "test")
+    assert_equal :html, @view.lookup_context.rendered_format
+  end
+
   def test_render_partial_implicitly_use_format_of_the_rendered_template
     @view.lookup_context.formats = [:json]
     assert_equal "Hello world", @view.render(:template => "test/one", :formats => [:html])