allow engine specific layout to be true, too

lib/sinatra/base.rb

@@ -679,21 +679,24 @@ module Sinatra
 
     def render(engine, data, options={}, locals={}, &block)
       # merge app-level options
-      options = settings.send(engine).merge(options) if settings.respond_to?(engine)
-      options[:outvar]           ||= '@_out_buf'
-      options[:default_encoding] ||= settings.default_encoding
+      engine_options  = settings.respond_to?(engine) ? settings.send(engine) : {}
+      options         = engine_options.merge(options)
 
       # extract generic options
       locals          = options.delete(:locals) || locals         || {}
       views           = options.delete(:views)  || settings.views || "./views"
       layout          = options.delete(:layout)
       eat_errors      = layout.nil?
-      engine_layout   = settings.send(engine)[:layout] if settings.respond_to?(engine)
-      layout          = engine_layout || @default_layout if layout.nil? or layout == true
+      layout          = engine_options[:layout] if layout.nil? or layout == true
+      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
 
+      # set some defaults
+      options[:outvar]           ||= '@_out_buf'
+      options[:default_encoding] ||= settings.default_encoding
+
       # compile and render template
       begin
         layout_was      = @default_layout

test/templates_test.rb

@@ -49,6 +49,21 @@ class TemplatesTest < Test::Unit::TestCase
     assert_equal "Layout 3!Hello World!", body
   end
 
+  it 'falls back to default layout if engine layout is true' do
+    mock_app do
+      template(:layout) { 'Layout!!! <%= yield %>' }
+      set :erb, :layout => true
+
+      get('/') do
+        erb('Hello World!', { :layout => true })
+      end
+    end
+
+    get '/'
+    assert ok?
+    assert_equal "Layout!!! Hello World!", body
+  end
+
   it 'renders String templates directly' do
     render_app { render(:test, 'Hello World') }
     assert ok?