Ruby already does this freeze for us.

CacheHelper is mixed in to Helpers, Helpers is mixed in to AV::Base.
This means we can count on instances of AV::Base to have the "cache hit"
method on them, and we can stop setting an ivar for cache logging and
just ask the view if it was a cache hit.

Freeze string literals and use String instead of
Regex inside gsub call. This should improve performance from 20% up to
50% on most cases.

Style/SpaceBeforeBlockBraces
Style/SpaceInsideBlockBraces
Style/SpaceInsideHashLiteralBraces

Fix all violations in the repository.

Many helpers mark content as HTML-safe without escaping double quotes -- including `sanitize`. Regardless of whether or not the attribute values are HTML-escaped, we want to be sure they don't include double quotes, as that can cause XSS issues. For example: `content_tag(:div, "foo", title: sanitize('" onmouseover="alert(1);//'))`

CVE-2016-6316

Caused by #26092.

A few have been left for aesthetic reasons, but have made a pass
and removed most of them.

Note that if the method `foo` returns an array, `foo << 1`
is a regular push, nothing to do with assignments, so
no self required.

Implement naive partial caching mechanism.

Add test for LogSubscriber

Use ActionView::Base#log_payload to store log_subscriber's payload, so we can pass cache result into it.

Fixed tests

Remove useless settings

Check if #log_payload exists before calling it. Because other classes also includes CacheHelper but don't have is attribute

Use @log_payload_for_partial_reder instead of #log_payload to carry ActionView's payload.

Update test's hash syntax

Add configuration to enable/disable fragment caching logging

Remove unless test and add new test to ensure cache info won't effect next rendering's log

Move :enable_fragment_cache_logging config from ActionView to ActionPack

Apply new config to tests

Update actionview's changelog

Update configuration guide

Improve actionview's changelog

Refactor PartialRenderer#render and log tests

Mute subscriber's log instead of disabling instrumentation.

Fix typo, remove useless comment and use new hash syntax

Improve actionpack's log_subscriber test

Fix rebase mistake

Apply new config to all caching intstrument actions

The current code base is not uniform. After some discussion,
we have chosen to go with double quotes by default.

We can safely assume we're not dealing with an infinite collection as
we're about to call `each` on it and collect the results until it
terminates on its own. Given that, `to_a` is implemented by the normal
Array-like objects, and less Array-like objects like `Enumerator` and
`Enumerator::Lazy`.

This will ensure we attempt to render an empty collection, meaning we
don't actually render anything at all. Allowing `nil` or a falsey value
through results in calling `render_partial` rather than
`render_collection`, which isn't what we want.

An optimization was introduced in
https://github.com/rails/rails/commit/27f4ffd11a91b534fde9b484cb7c4e515ec0fe77
which tried to `#to_ary` the collection to prevent unnecessary queries
for ActiveRecord scopes/relations. If the given collection did not
respond to `#to_ary`, and empty collection was returned. That meant you
couldn't use collections built from `Enumerator` nor `Enumerable`.

With this change, `#collection_from_options` will attempt the
optimization, but fall back to passing along the given collection,
as-is.

Where appropriate, prefer the more concise Regexp#match?,
String#include?, String#start_with?, or String#end_with?

Code like `render(topics) => render("topics/topic")` adds confusion
for the readers. On first impression, that code feels like hash kind
of data, but it's not. So make it more clear and meaningful.

[ci skip] Just some english and `<tt>` tags.

Also document return values for Proc/Symbol arguments

Fix a link to use RDoc syntax and make sure that the titles' level
match the section we are in since we are both documenting the new
and the legacy syntax.

- `partial` option is not used anymore, this was removed in https://github.com/rails/rails/pull/23724

- Remove repetative docs
- Fix grammar on sentences
- Add escaping for literals
[ci skip]

Removes littering `freeze` calls with Ruby 2.3's magic comment.

This is based on https://github.com/kangax/html-minifier/blob/6b2d4536d82819143b468b41a89c700b6c61631f/src/htmlminifier.js#L197 and
spec from https://www.w3.org/TR/html51/single-page.html.

Couple of other changes to tests due to support update:
- autobuffer has been dropped in favour of preload attribute, ref: https://msdn.microsoft.com/en-us/library/ff974743(v=vs.85).aspx
- pubdate attribute has been dropped from spec, ref:  https://www.w3.org/html/wg/tracker/issues/185

Freeze string for default content for tag_strings, which later goes on to create new content. This should also be inline with content being passed should not be mutable

Expand list of void elements to match spec from https://html.spec.whatwg.org/multipage/syntax.html#void-elements

`simple_format` handles `\r\n` and `\r` but previously did not document
this behavior. The handling is done with a `gsub` in `split_paragraphs`.

[ci skip]

A change was made in the helper that renders the `datetime`,
being now by default `datetime-local` and creating
an alias of `datetime-local` for `datetime`, `datetime` tag and
it passes to be an abstract class for all other tags that inherit from him.

As a new specification of the HTML 5 the text field type `datetime`
will no longer exist and will pass a `datetime-local`.
Ref: https://html.spec.whatwg.org/multipage/forms.html#local-date-and-time-state-(type=datetime-local)

The reason we are reverting this commit is because it created breaking
changes for file upload gems. For more information see discussion here:
https://github.com/rails/rails/issues/17947#issuecomment-225154294

This reverts commit c4558178, reversing
changes made to 8b3cd74b.

Conflicts:
	actionview/CHANGELOG.md
	actionview/lib/action_view/helpers/form_helper.rb

In PR #24929 the changelog was updated to make note that while the new
template handler was changed to raw this changed the behavior when
outputting plain html or js files. Previously ERB would output the files
unescaped. Changing the default handler to RAW meant that these same
files would be rendered as escaped rather than as js or html.

Because of this change in behavior and after the discussion #24949 in we
decided to change the behavior of the Raw handler to output html_safe
strings by default.

Now files rendered with the default handler (raw) render the file
unescaped.