Hey, everyone! Welcome to the latest edition of This Week in Rails - your one stop shop for all the goings-on in the Rails universe. My name is Todd and I'll be your guide. Let's get this party started!
This patch conditionally skips an expensive method call unless it's explicitly required when calling preload on an ActiveRecord::Relation. The net benefit is an overall reduction in allocated objects and ~40% increase in speed.
A regression in 4.2.3 would cause the relative_url_root and script_name to each be included in routes for mounted Engines (the expected behavior is for one, not both to be used). This patch resolves that issue on master and 4-2-stable.
pk_and_sequence_for is not used by MySQL adapters and is being removed. There won't be a deprecation cycle for this change, so note that your implementation may break if you're overriding this method anywhere.
That's all for This week in Rails. As always, there are many more changes than we have room to cover here, but feel free to check them out yourself.