Templates: render should fall back to engine layout sinatra#563

lib/sinatra/base.rb

@@ -688,7 +688,8 @@ def render(engine, data, options={}, locals={}, &block)
       views           = options.delete(:views)  || settings.views || "./views"
       layout          = options.delete(:layout)
       eat_errors      = layout.nil?
-      layout          = @default_layout if layout.nil? or layout == true
+      engine_layout   = settings.send(engine)[:layout] if settings.respond_to?(engine)
+      layout          = engine_layout || @default_layout if layout.nil? or layout == true
       content_type    = options.delete(:content_type)  || options.delete(:default_content_type)
       layout_engine   = options.delete(:layout_engine) || engine
       scope           = options.delete(:scope)         || self

test/templates_test.rb

@@ -34,6 +34,21 @@ def with_default_layout
     File.unlink(layout) rescue nil
   end
 
+  it 'falls back to engine layout' do
+    mock_app do
+      template(:layout3) { 'Layout 3!<%= yield %>' }
+      set :erb, :layout => :layout3
+
+      get('/') do
+        erb('Hello World!', { :layout => true })
+      end
+    end
+
+    get '/'
+    assert ok?
+    assert_equal "Layout 3!Hello World!", body
+  end
+
   it 'renders String templates directly' do
     render_app { render(:test, 'Hello World') }
     assert ok?