This will silence deprecation warnings.

Most of the test can be changed from `render :text` to render `:plain`
or `render :body` right away. However, there are some tests that needed
to be fixed by hand as they actually assert the default Content-Type
returned from `render :body`.

`head` method works similar to `render` method with `:nothing` option

It was returning false in normal circumstances.
This broke the `head :ok and return if` construct.
Add appropriate test.

Add http_cache_forever to ActionController, so we can cache results
forever.
Things like static pages are a good candidate for this type of caching.

This cache only controls caching headers, so it is up to the browser to
cache those requests.

The methods `fresh_when` and `stale?` from ActionController::ConditionalGet
accept a single record as a short form for a hash. For instance

```ruby
  def show
    @article = Article.find(params[:id])
    fresh_when(@article)
  end
```

is just a short form for:

```ruby
  def show
    @article = Article.find(params[:id])
    fresh_when(etag: @article, last_modified: @article.created_at)
  end
```

This commit extends `fresh_when` and `stale?` to also accept a collection
of records, so that a short form similar to the one above can be used in
an `index` action. After this commit, the following code:

```ruby
def index
  @article = Article.all
  fresh_when(etag: @articles, last_modified: @articles.maximum(:created_at))
end
```

can be simply written as:

```ruby
def index
  @article = Article.all
  fresh_when(@articles)
end
```

PR #18772 changed the parameters of `stale?` to use `kwargs`.
[As for this comment](https://github.com/rails/rails/pull/18872/files#r24456288)
the default value for the `etag` parameter should be `record`, not `nil`.

This commit fixes the code and introduces a test that:

- passed before #18872
- fails on the current master (after #18772)
- passes again after setting the default value of `etag` to `record`.

Non-kwargs requests are deprecated now.
Guides are updated as well.

`post url, nil, nil, { a: 'b' }` doesn't make sense.
`post url, params: { y: x }, session: { a: 'b' }` would be an explicit way to do the same

When `render` was moved from ActionPack to ActionView in acc8e259,
some fixtures required by the tests were duplicated, but they are
actually only required by ActionView tests.

To give one example, `double_render` is already defined [in the AV tests](https://github.com/rails/rails/blob/72139d8d310d896db78eaec98582c7a638135102/actionview/test/actionpack/controller/render_test.rb#L407)
and is never used in the ActionPack tests.

Commit 20fece14 introduced the `_status_code` method to fix calls to
`head :ok`. This method has been added on both ActionController::Metal
and ActionDispatch::Response.

As for the latter, this method is just equivalent to the `response_code`
one so commit aefec3c6 removed it from the `Reponse` object so call to
the `_status_code` method on an ActionController::Base instance would be
handled by the `Metal` class (which `Base` inherits from) but the status
code is not updated according to the response at this level.

The fix is to actually rely on `response_code` for ActionController::Base
instances but this method doesn't exist for bare Metal controllers so we
need to define it.

New default: the template digest is automatically included in your ETags.
When you call `fresh_when @post`, the digest for `posts/show.html.erb`
is mixed in so future changes to the HTML will blow HTTP caches for you.
This makes it easy to HTTP-cache many more of your actions.

If you render a different template, you can now pass the `:template`
option to include its digest instead:

  fresh_when @post, template: 'widgets/show'

Pass `template: false` to skip the lookup. To turn this off entirely, set:

  config.action_controller.etag_with_template_digest = false

This interface should be use when implementing renderers.

This reverts commit 70d6e16f, reversing
changes made to ea4db3bc.

Seems to be a code merge done by mistake.

Reset ActionView::Base.logger after tests

https://github.com/rails/etagger/pull/3

They don't add any benefits over `assert object.blank?`
and `assert object.present?`

      1) Failure:
    test_head_created_with_image_png_content_type(RenderTest) [test/controller/render_test.rb:1238]:
    Expected: "image/png"
      Actual: "image/png; charset=utf-8"

This resolves issues when rendering nested partials.
Previously the `PartialRenderer` was reused which led to
situations where the state of the renderer was reset.

Closes #8197

the documentation on #assert_template states that the :locals option is
only available in view test cases:

    # In a view test case, you can also assert that specific locals are passed
    # to partials:

I added a warning when it's passed in an inapropriate context to prevent
a NoMethodError.

Added controller-level etag additions that will be part of the action etag computation *Jeremy Kemper/DHH*

https://www.owasp.org/index.php/XSS_%28Cross_Site_Scripting%29_Prevention_Cheat_Sheet#RULE_.231_-_HTML_Escape_Before_Inserting_Untrusted_Data_into_HTML_Element_Content
Closes #7215

1. Change in test name as already defined.
2. ambiguous first argument; put parentheses or 
even spaces

Added test for case when view doesn't have logger method when using ActionController::Metal controller.

There are several aspects to this commit, that don't well fit into broken down
commits, so they are detailed here:

 * When a user uses response.headers['Cache-Control'] = some_value, then the
   documented convention in ConditionalGet is not adhered to, in this case,
   response.cache_control is ignored due to `return if
   self[CACHE_CONTROL].present?`
 * When a middleware sets cache-control headers that would clobber, they're
   converted to symbols directly, without underscores. This would lead to bugs.
 * Items that would live in :extras if set through expires_in, are placed
   directly in the @cache_control hash, and not respected in many cases
   (somewhat adhering to the aforementioned documentation).
 * Although quite useless, any directive named 'extras' would be ignored.

The general convention applied is that expires_* take precedence, but no longer
overwrite everything and expires_* are ALWAYS applied, even if the header is
set.

I am still unhappy about the contents of this commit, and the code in general.
Ideally it should be refactored to no longer use :extras. I'd likely recommend
expanding @cache_control into a class, and giving it the power to handle the
merge in a more efficient fashion. Such a commit would be a larger change that
could have additional semantic changes for other libraries unless they utilize
expires_in in very standard ways.

Add failing test re #3436 which demonstrates content_type is not respected when using the :head method/shortcut

In the current router DSL, using the +match+ DSL
method will match all verbs for the path to the
specified endpoint.

In the vast majority of cases, people are
currently using +match+ when they actually mean
+get+. This introduces security implications.

This commit disallows calling +match+ without
an HTTP verb constraint by default. To explicitly
match all verbs, this commit also adds a
:via => :all option to +match+.

Closes #5964

Closes #5632

Previously `rendered_format` was set only based on mime types
passed in Accept header, which was wrong if first type from
Accept was different than rendered partial. The fix is to simply
move setting rendered_format to the place where template
is available and grab format from the template. If it fails
we can fallback to formats passed by Accept header.

Fix for #5440

Removed max-stale from the tests since it's a request cache-control directive, just for clarity sake.