Fix extracting `references` via `order_values` to respect quoting

Extract `build_scope` and `predicate_builder` in `Reflection`

Ensure that using correct alias tracker

Remove unnecessary `tap` call on `ActionDispatch::MiddlewareStack.new`

[ci skip] Add missing space in security.md

Add `railtie.rb` to the plugin generator

Rails 5.1.2.rc1 regression - Clear offset cache on CollectionProxy reset/reload

Pass `structure_dump_flags` / `structure_load_flags` options before any other:

Remove needless gitignore

The dummy application is created under the tmp directory. Nothing is
created in the `test/dummy` directory.
https://github.com/rails/rails/blob/40bdbce191ad90dfea43dad51fac5c4726b89392/activejob/test/support/integration/helper.rb#L9

I guess that this comment makes it unnecessary.
https://github.com/rails/rails/pull/16541#r16986711

Covering #27994 in tests.

Closes #27994.

The AliasTracker#aliased_table_for needs the type caster for the joined association, not the join root

Add an option to silence puma in system tests.

This is motivated by our usage of system test in RSpec. Puma lazily
boots the first time a system test is used, but this causes some
unfortunate output to appear in the middle of the user's green dots. An
example of this can be seen in @derekprior's comment
[here](https://github.com/rspec/rspec-rails/pull/1813#issuecomment-309252314).

There are alternatives in RSpec where we attempt to intercept the puma
boot and prevent the output from being made there, but that would
involve some monkey patching. This seems like a cleaner solution.

Don't wrap parameters if key already exists

Removed reference to unexisting methods:

Guides: Clarify partial local variable naming. [ci skip]

Clarify the partial local variable name as being the same as the name
of the partial, minus the _leading_ underscore.

We shouldn't perform parameter wrapping if it would overwrite one of the
parameters sent with the request, as that would interfere with reading
the parameter directly from the top level `params` hash.

The current implementation has logic for this case, but it doesn't
handle `nil`/`false` values, which means these parameters:

    { "user" => nil }

are transformed into this `params` hash:

    { "user" => { "user" => nil } }

and `params["user"]` no longer returns the original parameter value.

`get/post_via_redirect`, `xhr` and his alias `xml_http_request` were respectively removed in 092033d5 and eb52e5d4

Fix typo in `AC::UnfilteredParameters` message [ci skip]

Ref: https://github.com/rails/rails/blob/33b596709388cc48d90ab6d1de99d7bd6e85f916/actionpack/lib/action_controller/metal/strong_parameters.rb#L52..L56

Do not use private API in bug report templates

Fix hash conditions documentation

Remove unused variable

This fixes the following warnings:

```
activerecord/test/cases/relation_test.rb:231: warning: assigned but unused variable - authors_with_commented_posts
```

`ActiveRecord::Migrator` is private API.
https://github.com/rails/rails/blob/bb9d6eb094f29bb94ef1f26aa44f145f17b973fe/activerecord/lib/active_record/migration.rb#L977

Therefore, it is not good to use it in bug report templates.
Instead, should use the public API `ActiveRecord::Migration#migrate`.

Avoid begin/rescue in fixture quoting

Keep INNER JOIN when merging relations

- On Mysql, some command line options that affect option-file handling such as `--no-defaults` have to be passed before any other options
- Modified rails to pass them right after the `mysql` command
- Ref https://dev.mysql.com/doc/refman/5.7/en/option-file-options.html and https://bugs.mysql.com/bug.php?id=83386
- Ref #27437

Scalar values like arrays and hashes can't be inserted
directly into table. Previously, the way to determine if
the value is scalar was to try quoting it. If `quote` raised
with an error than the value has to be converted to YAML.

This flow is not very obvious. Ideally we could have
a `quotable?` method in the connection, but I think
that we can avoid begin/rescue block by simply checking
if the value is Array or Hash.

https://github.com/rails/rails/commit/aa31d21f5f4fc4d679e74a60f9df9706da7de373