2 files changed, 7 insertions, 4 deletions
diff --git a/railties/lib/rails/application/finisher.rb b/railties/lib/rails/application/finisher.rb
index b722679ec2..afa79cad1c 100644
--- a/railties/lib/rails/application/finisher.rb
+++ b/railties/lib/rails/application/finisher.rb
@@ -27,17 +27,19 @@ module Rails
         end
       end
 
-      initializer :build_middleware_stack do
-        app
-      end
-
       # Fires the user-supplied after_initialize block (config.after_initialize)
+      # Should run before the middleware stack is built, because building the
+      # middleware already fires to_prepare callbacks in test and production.
       initializer :after_initialize do
         config.after_initialize_blocks.each do |block|
           block.call(self)
         end
       end
 
+      initializer :build_middleware_stack do
+        app
+      end
+
       # Disable dependency loading during request cycle
       initializer :disable_dependency_loading do
         if config.cache_classes && !config.dependency_loading
diff --git a/railties/lib/rails/engine.rb b/railties/lib/rails/engine.rb
index a158bb7b70..efa11b466a 100644
--- a/railties/lib/rails/engine.rb
+++ b/railties/lib/rails/engine.rb
@@ -15,6 +15,7 @@ module Rails
       def inherited(base)
         unless abstract_railtie?(base)
           base.called_from = begin
+            # Remove the line number from backtraces making sure we don't leave anything behind
             call_stack = caller.map { |p| p.split(':')[0..-2].join(':') }
             File.dirname(call_stack.detect { |p| p !~ %r[railties[\w\-]*/lib/rails|rack[\w\-]*/lib/rack] })
           end