Don't use this:

    scope :red, where(color: 'red')
    default_scope where(color: 'red')

Use this:

    scope :red, -> { where(color: 'red') }
    default_scope { where(color: 'red') }

The former has numerous issues. It is a common newbie gotcha to do
the following:

    scope :recent, where(published_at: Time.now - 2.weeks)

Or a more subtle variant:

    scope :recent, -> { where(published_at: Time.now - 2.weeks) }
    scope :recent_red, recent.where(color: 'red')

Eager scopes are also very complex to implement within Active
Record, and there are still bugs. For example, the following does
not do what you expect:

    scope :remove_conditions, except(:where)
    where(...).remove_conditions # => still has conditions

scope is syntactic sugar for defining a class method. Ruby allows
redefining methods but emits a warning when run with -w. So let's
not implement our own logic for this. Users should run with -w if they
want to be warned about redefined methods.

Remove blank line from generated migration

Fix adding/removing field's index when generating migration

When generating a migration that removes a field with an index, the down
will add both the field and its index.

We dont need to merge in the parameters as thats all being reset by the rack headers (and its causing problems for Strong Parameters attempt of wrapping request.parameters because it will change in testing)

Add missing require

Remove exclude option from ActionDispatch::SSL and fix secure cookies

keyword

Fixes issue #5222: DateTimeSelector builds invalid dates on leap days

changed all.map to pluck

Provide access to logger instance within TaggedLogging blocks

this improves encapsulation, simplifying occurrences like the following:

    Rails.logger.tagged("DEBUG") { Rails.logger.debug(msg) }

... by removing the need to rely on (i.e. repeat) outer variables:

    Rails.logger.tagged("DEBUG") { |logger| logger.debug(msg) }

Fixes issue #5222: DateTimeSelector builds invalid dates on leap day when discarding both day and month.

  Second security vulnerability found in mail file delivery method
  patched in version 2.4.4.

Build fix for app_generator_test.rb

Autosave association doesn't save all records on a new record for a collection association if there are records marked for destruction

time_tag support for blocks

Fix bug with autosave collection association on new record with a marked for destroy record in autosave collection.

Fix GH #5435. db:structure:dump should be re-enable.