allow 'all' for :domain option in addition to :all
Don't remove mailer layouts files
Remove custom errors page section from the guides

This pattern is too problematic and introduces a lot of edge cases:

  * On 4.2, the issue https://github.com/rails/rails/issues/15124 is
    back again.
  * needs to define each action for each http status otherwise the
    router raises ActionController::RoutingError (No route matches).
  * If the router has `match "/*username",...` and some action is
    missing, Rails will pick up the "match" and try to do its job.
  * encourages people to copy & paste programming. Not DRY.

[ci skip]
Fix Sidekiq ActiveJob integration setup

* .connect on a Redis connection wasn't valid
* Reset logger after we're done testing for redis connection to avoid
  "closed stream" error when starting server for real from a fork
Hide potentially sensitive ActiveJob params from logs

* Show GlobalID instead of full object .inspect output
Only filter GIDable objects; remove cosmetic changes
Require missing association in test
Fix "nonexistent" typo in tests
remove useless methods
Removed use of mocha in the info_controller tests
[ci skip] remove references to `Numeric#from_now`
skip test to get `sqlite3_mem` suite passing.
fixing mailer previews for apps with globbing route
document that `.delete` does work on `#readonly?` records. Closes #11860

[ci skip]

This is due to the fact that `.delete` is directly translated to SQL.
It tries to follow the same rules as `.delete_all` which is not able
to verify that records are `#readonly?`.
Failure to rollback t.timestamps when within a change_table migration

When running the following migration:

    change_table(:table_name) { |t| t/timestamps }

The following error was produced:

    wrong number of arguments (2 for 1) .... /connection_adapters/abstract/schema_statements.rb:851:in `remove_timestamps'

This is due to `arguments` containing an empty hash as its second
argument.
Move PredicateBuilder instantiation to constructor

In order to maintain thread safety and prevent race condition from memoization.
docs, add new changelog entries at the top :sweat: [ci skip] #17651
Active Record changelog needs to keep pointing at 4-2-stable. #17651

[ci skp]
Clarify that batching methods can be used with any orderable type primary key, not just integer ones, as per @a58cafeb3a86be46849de57481b6644094fb8165
Prevent Symbol GC