and defaults to `Digest::MD5`.

Replaced calls to `::Digest::MD5.hexdigest` with calls to `ActiveSupport::Digest.hexdigest`.

In #30510, `StatementPool` in `AbstractMysqlAdapter` was hidden in the
doc. But that class is also had in sqlite3 and postgresql adapters and
the base class is :nodoc: class.

Fixes #31282.

Not everyone uses iTerm2 and whereas Terminal.app on a mac just ignores
that and outputs the path, other terminals like those on Ubuntu do not.
A friendlier default is one that works by default.

Closes #31159
Closes #30957

Inverse instance should not be reloaded during autosave if called in validation

Use `credentials` instead of `keyfile` in GCS sevice

https://www.ruby-lang.org/en/news/2016/09/08/ruby-2-4-0-preview2-released/

See discussion in #31251

[ci skip] Correct output for Upcase

Add preload_link_tag helper.

The `keyfile` was renamed to `credentials` in `google-cloud-storage` 1.8.0.
https://github.com/GoogleCloudPlatform/google-cloud-ruby/blob/master/google-cloud-storage/CHANGELOG.md#180--2017-11-14

Although `keyfile` can still be used, but it looks like deprecate.
https://github.com/GoogleCloudPlatform/google-cloud-ruby/blob/ddf7b2a856d676316525eb581c1a4cc83ca6097b/google-cloud-storage/lib/google/cloud/storage.rb#L589...L590

Therefore, I think that should use `credentials` in newly generated
applications.

Ref: https://github.com/GoogleCloudPlatform/google-cloud-ruby/issues/1802

Refactor Date/Time next_occurring and prev_occurring

This helper creates a link tag with preload keyword that allows to
browser to initiate early fetch of resources. Additionally this send
Early Hints if supported.

See https://github.com/rails/rails/pull/30744/commits/59a02fb7bcbe68f26e1e7fdcec45c00c66e4a065
for more details about Early Hints.

Preload spec: https://w3c.github.io/preload/

Formatting fix for example code

Just cleaning up the formatting of the example code here to format an inline bit of commentary as a comment.

Before:

![](https://monosnap.com/file/Clso8IQGOWHU3o6cStbY5NaMPx3ysP.png)

After:

![](https://monosnap.com/file/QdbKKvLAeiQ0RucppVYETvaWEstnOI.png)




[ci skip]

These methods were originally added in https://github.com/rails/rails/pull/26600

This includes a couple of refactors to make these methods behave more similarly to other Date/Time extensions added by Active Support:

1. Use `advance` instead of `since` and `ago` to time-travel — this is particularly important to keep the returned instance’s class matching `self`.  Before this change:

    today = Date.today                     # => Tue, 28 Nov 2017
    today.class                            # => Date
    today.next_occurring(:wednesday)       # => Wed, 29 Nov 2017 00:00:00 UTC +00:00
    today.next_occurring(:wednesday).class # => ActiveSupport::TimeWithZone

  After this change, a Date (or Time, or DateTime) instance is properly returned (just like is shown in the new docs).  This is generally how everything else in DateAndTime::Calculations works.

2. Move the tests from the DateTime tests to the DateAndTimeBehavior tests.  The latter location is mixed in to the core_ext tests for _all_ of Date, Time, and DateTime to test the behavior across all of the classes.  The previous location is for testing core_ext functionality added specifically just to DateTime.

3. Better docs!

Scoping reserved names

[ci skip]Update docs `ActiveRecord::FinderMethods#find`

Action Mailer context for example responds to request but don't have a
a request object.

Fixes #31265

Fix typos and add a few suggestions

Fix optimized url helpers when using relative url root

Fixes #31220.

Due to inconsistent behavior when chaining scopes and one scope named after a Relation method

Validation code added in 2 places:

- scope, to prevent problematic scope names.
- enum, cause it tries to auto define scope.

[ci skip] Update MVC wiki link

ref https://github.com/rails/rails/pull/22653

Follow up of 924a368f

Include migration files in gem

Fixes #31245

There are two concerns which are both being combined into one here, but
both have the same goal. There are certain attributes which we want to
always consider initialized. Previously, they were handled separately.
The primary key (which is assumed to be backed by a database column)
needs to be initialized, because there is a ton of code in Active Record
that assumes `foo.id` will never raise. Additionally, we want attributes
which aren't backed by a database column to always be initialized, since
we would never receive a database value for them.

Ultimately these two concerns can be combined into one. The old
implementation hid a lot of inherent complexity, and is hard to optimize
from the outside. We can simplify things significantly by just passing
in a hash.

This has slightly different semantics from the old behavior, in that
`Foo.select(:bar).first.id` will return the default value for the
primary key, rather than `nil` unconditionally -- however, the default
value is always `nil` in practice.

Since #31173, mysql2 adapter depends on `automatic_close` which is
introduced since mysql2 0.4.3. So the adapter with the mysql2 version
before doesn't work with fork now.

```
% ARCONN=mysql2 be ruby -w -Itest test/cases/connection_adapters/connection_handler_test.rb -n test_forked_child_doesnt_mangle_parent_connection
Using mysql2
Run options: -n test_forked_child_doesnt_mangle_parent_connection --seed 19988

/Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/mysql2_adapter.rb:108:in `discard!': undefined method `automatic_close=' for #<Mysql2::Client:0x00007fedaa91dfd0> (NoMethodError)
```

This drops mysql2 version less than 0.4.3 to guarantee fork safety.

[ci skip] Fix documentation for deprecation method_wrappers