We can use `relation.last(index)[-index]` instead of loading all records
when using reversible order because `last` will call `reverse_order`.

Currently `last` with `offset` behaves incorrectly because `offset` can
not be reversed like `limit`. Therefore, `offset` should also be handled
like `limit`.

Commit 4ec5b0d6 was for fixing the regression #18787, but #28379 fixes
#18787 as well. So 4ec5b0d6 is no longer necessary.

Force :attachment as content disposition for some content types

In this way we avoid HTML, XML, SVG and other files that can be rendered
by the browser to be served inline by default. Depending on the origin
from where these files are served, this might lead to XSS
vulnerabilities, and in the best case, to more realistic phishing
attacks and open redirects.

We force it rather than falling back to it when other disposition is not
provided. Otherwise it would be possible for someone to force inline
just by passing `disposition=inline` in the URL.

The list of content types to be served as attachments is configurable.

Since #25037, `queue_adapter=` simply delegates to `interpret_adapter`
only.

Add missing require for `strip_heredoc`

Follow up of 09cac8c6.

- And move the Active Job related section down. Otherwise it was
  appearing as if the options are available for the `delivery_job`
  setting.

This is a partial revert of #26182. There is no reason to change the
default value.

Add support for multiple encodings in String.blank?

`assert_changes` should always assert some change

Currently reflections keeps the order when first added even if when
redefining association. As a result of the order, redefining through
association which use newly added association will raise
`HasManyThroughOrderError`. We need to redefine reflection order as well
when redefining association.

Fixes #31068.

Refactor tests for request parameters to use more realistic setup

This method which is used only in the internal was introduced in
ac384820 and was renamed in #17579. It does not need to be exposed.

An empty string is an invalid value in Ruby's range class.
So need to handle `Float::INFINITY` as it is and cast it in
`encode_range`.

Fixes #31612

Move `config.action_view.cache_template_loading` to proper section in configuring.md [ci skip]

Add bulk alter support for PostgreSQL

Remove dormant check

Use `count(:all)` in HasManyAssociation#count_records

fix the dirty tracking code's save hook overwriting missing attribute…

Seems some tests not work with Minitest 5.11.0.

* https://travis-ci.org/rails/rails/jobs/323997512#L1053
* https://travis-ci.org/rails/rails/jobs/323997486#L1055

Ref: https://github.com/seattlerb/minitest/issues/729

Improves 049a3374:

* Attempt native `preventDefault()` before stepping in
* Fix that calling `preventDefault()` more than once would throw an error
* Fix that non-cancelable events could be canceled

Follow up of #31606.

This is a regression test for #27864.

This method was introduced in #26718, which is internally used only in
`CollectionAssociation`. There is no need to be in the reflection
classes.

Refactor delegating `join_primary_key` instead of `join_keys` and `association_primary_key` in `TableMetadata`

Because `join_primary_key` is called by `join_keys` and it is to
abstract calling `association_primary_key`.

Bump license years for 2018

Clarify that it's public API and may be used in third-party analyzers.

Clarify that it's public API intended for use by third-party previewers. It shouldn't be removed without deprecation even though it isn't used by the built-in previewers.