Build/Test Tools: Move the PHP 7.3 Travis job in 5.0 branch after the JS tests, for consistency with other branches.

See #42387, #40407.

WordPress 5.0.8

Ensure that a user can publish_posts before making a post sticky.

Props: danielbachhuber, whyisjake, peterwilson, xknown.
Prevent  stored XSS through wp_targeted_link_rel().
Props: vortfu, whyisjake, peterwilsoncc, xknown,  SergeyBiryukov, flaviozavan.
Update wp_kses_bad_protocol() to recognize : on uri attributes,
wp_kses_bad_protocol() makes sure to validate that uri attributes don't contain invalid/or not allowed protocols. While this works fine in most cases, there's a risk that by using the colon html5 named entity, one is able to bypass this function.
Brings r46895 to the 5.3 branch.
Props: xknown, nickdaugherty, peterwilsoncc.
Prevent stored XSS in the block editor.
Brings r46896 to the 5.3 branch.
Prevent escaped unicode characters become unescaped in unsafe HTML during JSON decoding.
Props: aduth, epiqueras.

WordPress 5.0.7.

Backporting several bug fixes.

- Query: Remove the static query property.
- HTTP API: Protect against hex interpretation.
- Filesystem API: Prevent directory travelersals when creating new folders.
- Administration: Ensure that admin referer nonce is valid.
- REST API: Send a Vary: Origin header on GET requests.

Backports [46474], [46475], [46476], [46477], [46478], [46483], [46485] to the 5.0 branch.

WordPress 5.0.6

WordPress 5.0.5.

Update the block library to 2.2.17 to fix an issue with invalid shortcode blocks.

Props aduth, flaviozavan, epiqueras, jorgefilipecosta

jQuery: Backport the patch from jQuery 3.4.0.

Merges [45342] to the 5.0 branch.

Props MikeNGarrett, peterwilsoncc, azaozz.
Fixes #47020.

Fix for URL sanitization in `wp_kses_bad_protocol_once()`.

Merges [45997] to the 5.0 branch.

Props irsdl, sstoqnov, whyisjake.

Update the block library to 2.2.17 to fix an issue with invalid shortcode blocks.

Props aduth, flaviozavan, epiqueras

Improve handling the existing `rel` attribute in `wp_rel_nofollow_callback()`.

Merges [45990] to the 5.0 branch.
Props xknown, sstoqnov.

Improve URL validation in `wp_validate_redirect()`.

Merges [45971] to the 5.0 branch.
Props vortfu, whyisjake, peterwilsoncc.

Remove _convert_urlencoded_to_entities() from the get_the_content() callback.

Merges [45937] to the 5.0 branch.

Props vortfu, whyisjake, peterwilsoncc

Escape the output in `wp_ajax_upload_attachment()`.

Merges [45936] to the 5.0 branch.
Props whyisjake, sstoqnov.

Build/Test tools: Further trimming of CI jobs on the 5.0 branch.

This removes the PHP 5.6 job which runs without an object cache in place as the likelihood of a change being backported that only breaks 5.6 environments without an object cache is small.

See #42387

Build/Test tools: Switch npm dependency caching strategy on Travis CI.

This switches to caching npm's local cache instead of `node_modules` in order to prevent issues caused by modules compiled using a different version of node.

Merges [44993] into the 5.0 branch.

See #46632

Build/Test tools: Trim the test matrix on Travis in order to speed up the 5.0 branch build.

This removes the PHP 7.2, 7.1, 7.0, 5.5, 5.4, 5.3, and nightly jobs.

See #42387, #40407

WordPress 5.0.4, undoing the incorrect version bump in [44862].

WordPress 5.0.5

Comments: Improve comment content filtering.

Merges [44842] to the 5.0 branch.

Formatting: Improve `rel="nofollow"` handling in comments.

Merges [44833] to the 5.0 branch.

Post WordPress 5.0.3 version bump.

WordPress 5.0.3.

About: Add 5.0.3 details to the about page.

Fixes #45884.

Post WordPress 5.0.3-RC1 version bump.

WordPress 5.0.3-RC1.

Upload: Fix upload failures of common text file types.

This adds some special case handling in 'wp_check_filetype_and_ext()' that prevents some common file types from being blocked based on mismatched MIME checks, which were made more strict in WordPress 5.0.1.

Merges [44438], [44439], [44441], and [44442] to the 4.9 branch.

Props Kloon, birgire, tellyworth, joemcgill.
See #45615.

Block Editor: Display notice to the user when JavaScript is disabled.

Currently, when viewing the block editor with JavaScript disabled, the user sees a blank admin page with the admin menu sidebar. This adds an admin notice informing the user that JavaScript is required for the new block editor.

Props mkaz, pento, azaozz, ocean90, desrosj.

Merges [44437] to the 5.0 branch.
Fixes #45453.

Default Themes: Bump the version numbers and release dates.

Update the theme versions and release dates for the default themes, in time for WordPress 5.0.3.

The POT file for Twenty Eleven has also been updated.

Props laurelfulford.
Merges [44435] to the 5.0 branch.
Fixes #45792.

Bundled Themes: Bump script and style version numbers.

When existing scripts or styles are updated in default themes, the version numbers in the enqueues should also be bumped to make sure the old files don't cache. This update bumps version numbers for changes since version 5.0, for themes Twenty Eleven through Twenty Nineteen. 

Props laurelfulford.
Merges [44382] to the 5.0 branch.
Fixes #45679.

Twenty Twelve: Correct `padding` rule precedence for Quote block.

Props superpoincare.
Merges [44432] to the 5.0 branch.
Fixes #45794.

Bundled Themes: Make sure button blocks respect settings.

When the original block editor styles were added to the existing default themes, the button blocks were styled to match how each theme styled the `button` tag. 

However, the styles should respect the block editor's default style, "Rounded", and allow switching to the other styles, like "Outlined" and "Square".

Props laurelfulford.
Merges [44381] to the 5.0 branch.
Fixes #45541.

Twenty Nineteen: Update theme description and tags.

The original theme description in Twenty Nineteen was intended as a placeholder; this update replaces it with a proper description, and removes the unnecessary `theme-options` tag. 

Props jobthomas, kjellr.
Merges [44377] to the 5.0 branch.
Fixes #45693.

Twenty Nineteen: Push right-aligned image block outside of text column.

Update right-aligned image block styles to push them outside of the text column on the front end, to match the original design and how the block looks in the editor.

Props kjellr, joen, allancole.
Merges [44371] to the 5.0 branch.
Fixes #45716.

Twenty Nineteen: Remove transparency from submenus.

On pages and posts with featured images, the top level menu items have a slight transparency on hover, which was being inherited by their submenus. This update removes that inheritance, improving readability and consistency in the menu's appearance. 

Props kjellr.
Merges [44368] to the 5.0 branch.
Fixes #45689.

Twenty Nineteen: Improve menu semantics and keyboard navigation.

The menu's original markup included some non-semantic tags and an unnecessary tabindex attribute that made it difficult to navigate via keyboard. 

Props allancole, anevins, kjellr.
Merges [44376] to the 5.0 branch.
Fixes #45713.

Twenty Seventeen: Improve selectors for block editor custom colors.

Twenty Seventeen's original styles for the block editor custom colors had some issues: they weren't being applied to the button blocks due to lack of specificity, and when applied to paragraph blocks, there was no padding in the editor. This update makes sure the colors and related styles work as expected.

Props laurelfulford.
Merges [44402] to the 5.0 branch.
Fixes #45426.

Twenty Nineteen: Fix hover appearance for outlined button block style.

The outlined button block style was displaying white text on a white background on hover. This update makes sure the text remains legible on hover when this button style is applied. 

Props rickalee, kjellr.
Merges [44370] to the 5.0 branch.
Fixes #45726.

Twenty Fourteen: Remove text decoration from button block.

The button block in Twenty Fourteen was incorrectly inheriting a text underline from the theme's link styles.

Props bobbingwide.
Merges [44378] to the 5.0 branch.
Fixes #45732.

Twenty Nineteen: Remove underline from "Continue Reading" arrow.

The "Continue Reading" link that's generated by the More block is styled to include an arrow next to the text; that arrow shouldn't inherit the text underline style. This update removes it. 

Props littlebigthing, kjellr.
Merges [44369] to the 5.0 branch.
Fixes #45715.

Twenty Fourteen: Correct video play button position.

A change to the MediaElement.js caused Twenty Fourteen's custom video play button to display in the top corner, rather than centered. This update returns it to its correct position. 

Props mmaumio, celloexpressions.
Merges [44380] to the 5.0 branch.
Fixes #44664.

I18N: Expose JSON translation file paths in `load_script_textdomain()`.

Removes `file_exist()` checks before calling `load_script_translations()` to let the determined paths be passed to `load_script_translations()` which provides its own file check and the possibility to filter the path.

Merge of [44418] to the 5.0 branch.

Props swissspidy, johnbillion, ocean90.
Fixes #45769.

Twenty Seventeen: Use a simple counter incremented with each call instead of `uniqid()` for generating unique IDs for HTML elements.

Props westonruter, laurelfulford.

Merges [43659] and [44408] to the 5.0 branch.
Fixes #44883.

General: Introduce `wp_unique_id()`, a PHP implementation of Underscore's `uniqueId` method.

A static variable contains an integer that is incremented with each call. This number is returned with the optional prefix.
As such the returned value is not universally unique, but it is unique across the life of the PHP process.

Props westonruter, dlh.

Merges [43658] and [44406] to the 5.0 branch.
See #44883.

Accessibility: Insert Link modal: Improve keyboard interaction.

Avoids change the selected link when using the Shift + Up/Down arrow keys
to select text in the form fields.

Props afercia.

Merges [42807] to the 5.0 branch.
Fixes #43253.

I18N/Script Loader: Support text domains other than "messages".

The inline JavaScript added by `WP_Scripts::print_translations()` should check whether `locale_data.$text_domain` exists and fall back to `locale_data.messages` otherwise.

Merge of [44403] to the 5.0 branch.

Props swissspidy.
Fixes #45441.

Editor: Use explicit context instead of a trailing space for Edit string in TinyMCE.

In [42523], `trunk` was updated to use explicit context instead of a trailing space for the Edit string in TinyMCE plugins. [43472] later backported this change, but the string in `class-wp-editor.php` was missed. This fixes the `Edit` string so not display as `Edit|button` in the 5.0 branch.

Props dimadin.

See #42543, #44134.
Fixes #44919.

Editor: Allow the “Add Media” button tooltip to be translated in the Classic block.

In the Classic Editor, the “Add Media” button was outside of the TinyMCE editor. In the Block Editor, the “Add Media” button was moved into the TinyMCE toolbar in the Classic block, but the tooltip was not added to the list of translatable strings. This adds “Add Media” to that list.

The corresponding keyboard shortcut is also specified for the “Add Media” button.

Props afercia.

Merges [44398-44399] to the 5.0 branch.
Fixes #45788.

Script Loader: Load unminified package vendor scripts when `SCRIPT_DEBUG` is set.

The unminified package vendor scripts are bundled with the release package thus the value of the `SCRIPT_DEBUG` constant should be honored.

Merge of [44391] to the 5.0 branch.

Props earnjam.
Fixes #45535.

Customize: Safeguard a check on the `customize_validate_{$setting_id}` filter value to ensure it is a `WP_Error`.

While the filter is documented to only support a `WP_Error`, it has been a common practice to return true in a validation function if no errors have occurred. This was already caught when the same filter was executed in `WP_Customize_Setting`, it was however missing in `WP_Customize_Manager::validate_setting_values()`.

Props flixos90.

Merges [43578] to the 5.0 branch.
Fixes #44809.

Block Editor: Upgrade `@WordPress` packages to the latest versions.

Updated packages:

- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]
- @wordpress/[email protected]

Props: youknowriad, gziolo, desrosj.

Merges [44389] to the 5.0 branch.
Fixes #45814.

Customize: Pass missing parameter to `dynamic option_{$option}` filter in `WP_Customize_Widgets::capture_filter_pre_get_option()`.

This prevents a potential fatal error from an `ArgumentCountError` exception in PHP 7.1 or greater

Props dlh.

Merges [43561] to the 5.0 branch.
Fixes #44770.

Happy New Year!

Fixes Tests_Basic::test_license

Merges [44379] to the 5.0 branch.

Props jorbin.

Twenty Nineteen: Make sure links are followed on touchend, not touchstart.

The theme's original navigation JavaScript was making it so all links on a site were immediately followed on touchstart when using a touch-enabled device. This update makes sure links are followed at touchend, to improve usability and menu behavior.

Props anevins, panchen, kjellr.
Fixes #45510.

Post WordPress 5.0.2 version bump.

WordPress 5.0.2.

Posts, Post Types: Correctly show hierarchical post type hierarchy in admin.

In [44185], a bug was introduced where hierarchical post types would not display in the correct default order (hierarchically).

This was caused by a `! isset()` check, which returned `false` after [44185], causing the correct default value to not be applied. This switches that conditional to use an `empty()` check, ignoring the new empty string assignment that was added to prevent a PHP notice when `compact()` is called.

Merges [44338] to the 5.0 branch.

Props davidbinda.
Fixes #45711.

About: Add 5.0.2 details to the about page.

Props desrosj.
Fixes #45703.

Default Themes: Bump the version numbers and release dates.

Update the theme versions and release dates for the default themes, in time for WordPress 5.0.2.

The POT files for Twenty Ten and Eleven have also been updated.

Merges [44322] into the 5.0 branch.
Fixes #45681.

Post WordPress 5.0.2 RC2 version bump.

WordPress 5.0.2 RC2

i18n: Remove the `script_loader_src` filter from `load_script_textdomain()`.

This filter is superfluous here, the `load_script_textdomain_relative_path` should be used for customising the textdomain path.

See #45528.
Props dimadin.

Block Editor: Upgrade @WordPress packages to the latest version (4.7.1)

Updated packages:

 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]

Props youknowriad, pento.

Fixes #45637.

i18n: Prevent a PHP warning when a mu-plugin loads a textdomain.

`determine_locale()` accesses the `$pagenow` global, but this is set after mu-plugins are loaded, so we need to check that it's been set.

Props swissspidy, azaozz.
See #45668.

Post WordPress 5.0.2 RC1 version bump.

WordPress 5.0.2 RC1.

Block Editor: Remove a deprecated notice being generated by the meta box compat functions.

See #45456.

Twenty Seventeen: Update `font-family` for Simplified Chinese (zh_CN).

Fix the `font-family` used for Simplified Chinese (zh_CN) in the block editor CSS.

Props vaishalipanchal, ze3kr.
Fixes #45408.

I18N: Introduce `load_script_translations()` as a wrapper for loading and filtering translation data for JavaScript files.

* Introduces `pre_load_script_translations` to short-circuit the function.
* Introduces `load_script_translation_file` to filter the file path for loading script translations.
* Introduces `load_script_translations` to filter the JSON-encoded translation data.

Props johnbillion, strategio, swissspidy, dimadin, ocean90.
See #45425.

Script Loader: Pass the suffix to package style handles to ensure correct file names for minified RTL stylesheets.

See #45547.

Bundled Themes: Replace “Gutenberg” in code comments and classes.

This update replaces the term “Gutenberg” in the themes code comments and classes with something more future-friendly.

Fixes #45452.

Bundled Themes: Update default block appender selector.

The markup for the default block appender changed from a text input to a text area in the editor; this update makes the same change in the default theme styles.

Fixes #45450.

Script Loader: Misplaced parenthesis when `wp-tinymce-lists` is added.

A closing parenthesis was misplaced in the `$scripts->add( 'wp-tinymce-lists' )` call, causing the dependencies and version to be incorrectly passed to `includes_url()` instead.

Props volodymyrkolesnykov.
Fixes: #45506.

Twenty Sixteen: Fix superscript and subscript.

When using the block-based editor in Twenty Sixteen, superscript is displaying below the baseline and subscript is displaying above the baseline. This is the opposite of what should occur. This reverses the two to display correctly.

Props greg-raven, torontodigits, JDTrower.
Fixes: #44776.

I18N: Fix JavaScript translations for subdirectory installations.

Fixes the `load_script_textdomain` function not resolving the md5 hash based on the relative path for WordPress installations in a subdirectory. Also adds a filter to allow sites using CDNs or other alternative asset locations to filter the relative path resolution.

Props akirk, fierevere, swissspidy, mypacecreator, babaevan, tmatsuur, ocean90.
Fixes #45528.

Scripts: Remove an incorrect parameter sent to `wp_get_script_polyfill()`.

`wp_get_script_polyfill()` only accepts two parameters, but this call was passing a third.

Props swissspidy.
See #45472.

REST API: Remove a duplicate `require_once()`.

In `WP_REST_Attachments_Controller::create_item()`, `wp-admin/includes/image.php` was being `require_once()`-ed... twice. The superflous `require_once()` has been quietly removed.

Props david.binda.
See #45420.

Twenty Seventeen: Remove editor style that prevents images from being resized.

Twenty Seventeen’s editor styles contained an Internet Explorer 8 specific fix that stopped images from being scalable in the editor in other browsers. Since the editor no longer supports IE8, this fix can safely be removed. 

Props audrasjb, mihaivalentin, subrataemfluence.
Fixes #39738.

Twenty Seventeen: Add focus style to cookies consent checkbox.

To improve accessibility, the cookies content checkbox in the comment form needed some visible indication when it’s in focus. 

Props pratikthink, afercia.
Fixes #44699.

Twenty Seventeen: Remove unnecessary `ol` styles from editor.

Twenty Seventeen was designed with bolded numbers for its ordered list styles. This was removed from the theme prior to launch, but it was left in the editor styles, so it needed to be removed there, too.

Props mmaumio, edpittol.
Fixes #44775.

Twenty Nineteen: Fixes and improvements.

This commit fixes the final differences between the version of Twenty Nineteen in core and the one in GitHub. The two are now identical.

See #45424.

Twenty Nineteen: Fixes and improvements.

This commit brings over several changes that occurred upstream in the theme’s GitHub repository into core.

- Fix left/right-aligned pullquote spacing. https://github.com/WordPress/twentynineteen/pull/695
- Improve `readme.txt` to follow the correct standards for themes. https://github.com/WordPress/twentynineteen/issues/689

Props kjellr, allancole.

See #45424.

Twenty Sixteen: Fix button block custom colors on front end.

Simplify some of the button block’s CSS selectors in the theme, to make sure the default colors don’t override the custom colors on the front end.

Fixes #45427.

Twenty Nineteen: Fixes and improvements.

This commit brings over several changes that occurred upstream in the theme’s GitHub repository into core.

- Fixes some minor code quality issues. https://github.com/WordPress/twentynineteen/pull/237
- Fix PHP Warning: Parameter must be an array or an object that implements Countable. https://github.com/WordPress/twentynineteen/pull/661
- Add missing text domain and escaping to comment author text. https://github.com/WordPress/twentynineteen/pull/274
- Remove hyphens rule for cover image text. https://github.com/WordPress/twentynineteen/pull/691

Props khleomix, grapplerulrich, iCaleb, kjellr, allancole.

See #45424.

Twenty Fifteen: Fix button block custom colors on front end.

Simplify some of the button block’s CSS selectors in the theme, to make sure the default colors don’t override the custom colors on the front end.

Fixes #45428.

Twenty Fourteen: Fix button block custom colors on front end.

Simplify some of the button block’s CSS selectors in the theme, to make sure the default colors don’t override the custom colors on the front end.

Fixes #45429.

Twenty Nineteen: Fixes and improvements.

This commit brings over several changes that occurred upstream in the theme’s GitHub repository into core.

- Fix the gallery caption link color. https://github.com/WordPress/twentynineteen/pull/687
- Remove left padding from pullquote blocks. https://github.com/WordPress/twentynineteen/pull/690
- Print `skip-link-focus-fix` inline instead of enqueueing as blocking script. https://github.com/WordPress/twentynineteen/pull/47
- Fix and improve some strings with placeholders. https://github.com/WordPress/twentynineteen/pull/217

Props kjellr, allancole, dimadin, westonruter.

See #45424.

Twenty Thirteen: Fix button block custom colors.

Simplify some of the button block’s CSS selectors in the theme, to make sure the default colors don’t override the custom colors on the front end.

Also make sure the button’s gradient is not applied when a custom background color is added, since it will hide it. 

Fixes #45431.

Twenty Twelve: Fix button block custom colors.

Simplify some of the button block’s CSS selectors in the theme, to make sure the default colors don’t override the custom colors on the front end.

Also make sure the button’s gradient is not applied when a custom background color is added, since it will hide it. 

Fixes #45432.

Updating Twenty Nineteen, the new default theme for 2019.

This update changes the following: 

- Add proper frontend styles for center aligned archive and category blocks. More info here: https://github.com/WordPress/twentynineteen/pull/684
- Fix image_filter theme option conditional function. More info here: https://github.com/WordPress/twentynineteen/pull/680
- Remove duplicate rule-line when a separator block is followed by H1/H2 in the editor. Props richtabor. More info here: https://github.com/WordPress/twentynineteen/pull/686

Props richtabor, kjellr.

See #45424.

Updating Twenty Nineteen, the new default theme for 2019.

This change properly sets the primary color hue theme option. 

- More info: https://github.com/WordPress/twentynineteen/pull/683

Props richtabor.

See #45424.

Twenty Eleven: Fix button block custom colors on front end.

Simplify some of the button block’s CSS selectors in the theme, to make sure the default colors don’t override the custom colors on the front end.

Fixes #45433.

Twenty Eleven: Correct block editor `font-size` issue.

Update a mistake in Twenty Eleven's block editor styles that erroneously sets the `font-size` to `300`, when it should set the `font-weight` to `300`. This was causing browsers in quirks mode to make the editor font size very large. 

Fixes #45421.

Updating Twenty Nineteen, the new default theme for 2019.

This update changes the following: 

- Reverts the customization to the toolbar for wide and full blocks to make them more usable. More info here: https://github.com/WordPress/twentynineteen/pull/668
- Add nowrap to the columns block at breakpoints above 600px. More info here: https://github.com/WordPress/twentynineteen/pull/674

Props joen, kjellr.

Fixes #45369.

See #45424.

Twenty Ten: Custom colors should override `:visited` link styles on blocks.

Make sure the block editor custom colors in the theme also override the theme's `:visited` link styles. This prevents contrast issues, like in the button block -- when the background is dark, the purple `:visited` link can be difficult to read.

Fixes #45434.

Updating Twenty Nineteen, the new default theme for 2019.

This change adds general code quality and documentation improvements. 

- More info here: https://github.com/WordPress/twentynineteen/pull/546

Props grapplerulrich, iCaleb.

PHP 7.3 Compatibility: Fix compact related notices.

In PHP 7.3, the `compact()` function has been changed to issue an `E_NOTICE` level error if a passed string refers to an unset variable. In previous versions of PHP, this notice was silently skipped. This fixes a few more instances of unset variables in the WordPress admin.

The full RFC can be viewed here: https://wiki.php.net/rfc/compact.

See #44416.
Fixes #45483.

Block Editor: Upgrade @wordpress packages to the latest version (4.7).

Updated packages:

 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]

This also includes the updates the Core blocks.
The script loader is updated to match the Gutenberg repository too.

Props atimmer, gziolo, joen.
Fixes #45442, #45637.

Post-5.0.1 version bump for 5.0 branch.

Bump 5.0 branch to version 5.0.1.

Multisite: Validate activation links.

Merges [44048] to the 5.0 branch.

Editor: Remove unwanted fields before saving posts.

The `meta_input`, `file`, and `guid` fields are not intended to be updated through user input.

Multisite: Improve messaging for previously activated users.

Ensure activation of a site is not attempted multiple times and users are shown the correct message if they follow the link a second time.

Merges [44021] to the 5.0 branch.

KSES: Correct `@since` tags for `wp_kses_uri_attributes`.

r44014 introduced the `wp_kses_uri_attributes` function and filter, but incorrectly used `4.9.9` instead of `5.0.1`.

KSES: Make the URI attributes DRY.

This commit introduces the `wp_kses_uri_attributes` function and filter. The function centralizes the list of attributes, in order to prevent inconsistency, and the filter provides a way for plugins to customize the attributes.

KSES: Conditionally remove the `<form>` element from `$allowedposttags`.

To avoid backwards compatibility issues, `<form>` is re-added if a custom filter has added the `<input>` or `<select>` elements to `$allowedposttags`.

Media: Improve verification of MIME file types.

WordPress 5.0.1-alpha.

WordPress 5.0.

Help/About: Upload videos to CDN and remove autoplay/loop.

Props skithund, afercia, lonelyvegan.
See #45178.

About: Move images to the CDN, and use `<picture>`.

Ensures the correct assets are used for the device loading the page.

Props joemcgill.
See #45178.

About: Add ℹ️ to the classic editor link, to make it stand out a little more.

Props melchoyce.
See #45178.

Post WordPress 5.0 RC3 version bump.

WordPress 5.0 RC3.

Default Themes: Bump the version numbers and release dates.

With WordPress 5.0 just a few short days away, the default themes can have their version numbers bumped.

The POT files for Twentys Ten and Eleven have also been updated.

Props laurelfulford, maedahbatool, mrahmadawais, pento.
See #45167.

Twenty Nineteen: Update the screenshot.

The screenshot is now up to date with the theme, and reflects the visuals in the About page.

Props kjellr, allancole.
See #45424.

Twenty Nineteen: Fix classic block icons not displaying with non-latin fonts.

Props kjellr, allancole.
See #45424.

Twenty Nineteen: Fix non-breaking spaces being too wide on the front end.

This visual issue had been previously fixed in the block editor, is now fixed in the published post, too.

Props kjellr, allancole.
See #45424.

Scripts: Ensure sub-directory WordPress installs can load polyfill scripts.

`wp_get_script_polyfill()` bypasses `WP_Scripts::do_item()`, so didn't transform the script path into its fully qualified URL.

Props swissspidy, ocean90.
See #45469.

l10n: Ensure JavaScript language packages are loaded for the user locale.

`load_script_textdomain()` had a reversed check to decide if the user locale should be loaded. This check is now replaced with `determine_local()`.

Props ocean90.
See #45465.

Post WordPress 5.0 RC2 version bump.

WordPress 5.0 RC2.

Updating Twenty Nineteen, our new default theme for 2019, set for 5.0.

This changes fixes a security issue found in a dependency script used in our build tool. 

- The malicious dependency is now removed and no longer called when running `npm install` or `npm run build`. 
- More info here: https://github.com/WordPress/twentynineteen/pull/675

Props allancole, kjellr, netweb, twoabove.

Block Editor: Update @wordpress package dependencies.

Updated packages

 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]

Other changes:

 - Backport the parser changes.

Fixes #45145.

Update `sidebars_widgets` to match Twenty Nineteen's single widget area

* Also update the customizer tests to match it.

Props SergeyBiryukov, pento.

Help/About: Update "Support for the Classic Editor plugin will remain in WordPress until 2021" to "through 2021" to further clarify timeline.

Props kjellr.
See #45178.

Help/About: Fix the user's saved WordPress.org username from being changed to wordpressdotorg when they click the About page link to install the Classic Editor plugin.

Props pento.
See #45178.

Block Editor: Remove the latest "gutenberg" mention in the latest-comments.php file

Props swissspidy.
See #45145.

Block Editor: Rename the gutenberg_ functions in blocks/latest-comments.php.

This was ported manually from https://github.com/WordPress/gutenberg/pull/12326

Props pento, swissspidy.
See #45145.

Block Editor: Update @wordpress package dependencies.

Update packages:

 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]
 - @wordpress/[email protected]

Other changes:

Fix a translator comment in edit-form-blocks.php.
Rename the gutenberg_ functions in blocks/latest-comments.php.

Props pento.
Fixes #45145.

Help/About: Do not show the "Keep it Classic" section and the link to it at the top when the Classic Editor plugin is already installed.

See #45178.

Help/About: Minor updates.

- Updated the various images.
- Added new "developer happiness" images.
- Fixed the responsive figcaption styles.
- Added a link to wporg plugin favorites as a shortcode to get to the classic plugin.
- Renamed "cover image" to "cover."
- Updated CSS to account for small-screen issues.

Props desrosj, audrasjb, antpb, jjj, elrae, Otto42, afercia, karmatosed, kjellr, alexislloyd, melchoyce.
See #45178.

Block Editor: Clarify a translator comment in meta box handling.

Props ocean90.
See #45217.

Post WordPress 5.0 RC1 version bump.

WordPress 5.0 RC1.

Block Editor: Fix the WordPress packages and vendor script registration.

The version is set properly and the scripts are automatically loaded in the footer.
This patch also includes a revert for the reusable blocks enqueue script.

Props pento, swissspidy.
Fixes #45402.
See #45396.

Block Editor: Add a placeholder for meta boxes that don't work in the block editor.

If a meta box is registered with the `__block_editor_compatible_meta_box` set to `false`, it's indicating that it doesn't work in the block editor. If that's the case, we can add a place holder to inform the user that they'll need to use the classic interface to work with this meta box.

Props pento, jorgefilipecosta, peterwilsoncc, karmatosed, noisysocks, dd32.
See #45217.

Query: Remove nextpage block delimiters when setting up global post data.

`WP_Query::setup_postdata()` splits the post up by `<!--nextpage-->`, which causes invalid block data to be contained in the post content.

This change removes the `<!-- wp:nextpage -->` and `<!-- /wp:nextpage -->`, as well.

Props pento, youknowriad, azaozz, noisysocks.
See #45401.

Block Editor: Refresh nonces used by wp.apiFetch.

Adds heartbeat nonces refreshing support to wp.apiFetch requests.

Props pento, adamsilverstein, dd32, desrosj.
Fixes #45113.

About: Update Freedoms page to include illustrations.

@cathibosco has made some great illustrations of the Four Freedoms on https://wordpress.org/about/. Let's bring that over to the admin Freedoms page.

Props @melchoyce, @cathibosco, @boemedia, @karmatosed, @tobifjellner, @helen, @matveb, @mcsf.
Fixes #45386.

Help/About: Add copy for new block editor.

Adds information about the new block editor (Gutenberg) and the Classic Editor
to the about page.

Props @pixelverbieger, @ocean90, @melchoyce, @boemedia, @sami.keijonen, @TimothyBlynJacobs, @xkon, @afercia, @Otto42, @pento.
Fixes #45178.

Block Editor: Fix loading the script handling the "Manage Reusable Blocks" page.

This ensures the "import from JSON" and "export JSON" buttons are shown properly.
The script is loaded in the footer because it relies on the DOM being already there.

Props noisysocks, mukesh27.
Fixes #45396.

Block Editor: Update @wordpress package dependencies

Updates packages:

- block-library
- components
- edit-post
- editor
- format-library
- list-reusable-blocks
- nux

See #45145

WPDB: Check that `$wpdb->last_result` is countable before counting with it.

`wpdb::get_col()` iterates over `$wpdb->last_result`, which can be a non-countable value, should the preceeding query have failed.

Props spacedmonkey, desrosj.
See #45299.

Build Tools: Don't minimise CSS in the unminimised files.

See #45201.

Build Tools: Tweak the webpack config for unminified files.

[43931] unintentionally caused the unminified files to wrap the code in an `eval()` call. 

See #45201.

Build Tools: Don't include `.map` files in the build.

These files are fairly large, and while they're useful in development, they're not needed in the final build.

Props pento, mcsf.
See #45201.

Formatting: Revert pre-save filter adding `rel="noopener"`.

Removes filters adding `rel="noopener"` to links targeting `_blank`.

Previous implementation could introduce blank `rel` attributes and could corrupt JSON data when saving via the customizer.

See #43187.
Reverts [43732] and [43733] from the 5.0 branch.

Updating Twenty Nineteen, our new default theme for 2019, set for 5.0.

This update changes the following: 

- Add dynamic theme version to stylesheet enqueue.

Props grapplerulrich, kjellr.

Updating Twenty Nineteen, our new default theme for 2019, set for 5.0.

This update changes the following: 

- Fixes link colors within solid-color pullquote blocks.

Props kjellr, xkon.

Updating Twenty Nineteen, our new default theme for 2019, set for 5.0.

This update changes the following: 

- Fix social-menu and site-logo alignment.

Props kjellr, xkon.

Updating Twenty Nineteen, our new default theme for 2019, set for 5.0.

This update changes the following: 

- Add PHPCS code quality fixes for functions.php
- Update stylesheets with a fresh Sass re-compile

Props xkon, kjellr

Core Editor: Specify script versions for the WordPress packages and their vendor dependencies.

Using the package.json versions of the npm dependencies as versions when registering 
the WordPress scripts.

Props dimadin, dd32.
Fixes #45187.

Block Editor: Clarify PHP Docs of the block_version function.

Clarify the return value.

Props desrosj, mukesh27.
Fixes #45342.

Block Editor: Fix PHP warning showing up when loading editor styles while in RTL.

In RTL languages, WordPress adds style-editor-rtl.css editor styles to the global $editor_styles
This patch ignores handling these styles if the file is not preset.

Props desrosj, mostafa.s1990.
Fixes #45288.

About Page: Update images and de-italicize a11y note.

Props @matveb, @kjellr, @Alexis Lloyd, @courtney0burton, @melchoyce.
See #45178.

Warn users of Gutenberg plugin of its deactivation upon 5.0 upgrade.

Fixes #45073.

Block Editor: Show privacy help notice on Privacy Policy page.

When editing a page set to be the Privacy Policy page, display a help notice
containing a link to the Privacy Policy guide.

This changeset ports this functionality to the new Block Editor.

Props desrosj.
Fixes #45057.

Block Editor: Update @WordPress dependencies to match Gutenberg 4.5.1.

Updates packages: annotations,
api-fetch,
block-library,
blocks,
components,
core-data,
data,
dom, edit-post,
editor,
format-library,
jest-console,
jest-preset-default,
keycodes,
html-entities,
list-reusable-blocks,
notices,
nux,
rich-text,
scripts,
token-list, url,
viewport

Fixes undefined notices in some blocks. Removes incorrect `'gutenberg'` textdomain too.

See #45145

REST API: Preserve unknown, respect `null` in server-side block rendering.

* Skips validation where there is no attribute definition, but keeps the attribute value. Previously, the attribute would be omitted from the attributes passed to `render_callback`. Notably, this resolves an issue where `render_callback` cannot receive a block's `align` and `customClassName` attribute values, since these are defined as a client-side filter.
* Validates `null` as a proper value in its own right. Previously, a client implementation of a block could track `{"attribute":null}` as an explicitly empty value, and the server would wrongly initiate defaulting behavior. The new behavior will now only populate a default value if the attribute is not defined at all, including when unset in its being invalid per the attribute schema.

Props aduth, noisysocks, youknowriad.
See #45145 for the patch, #45098 for the original ticket.

REST API: Always include `title.raw`/`content.raw` for Blocks in `context=view`.

Demarcations for reusable blocks are always expected to be accessible by clients.

Props noisysocks, youknowriad.
See #45145 for the patch, #45098 for the original ticket.

Block Editor: Expose value of `user_can_richedit()`.

In order for the Block Editor to know whether to allow visual editing, it needs to know the value of `user_can_richedit()`.

Props youknowriad.
Fixes #45375.

TinyMCE: Fix the keyboard shortcut (Alt+Shift+H) to not open the default Block Editor help modal and change the title of the help modal to "Classic Block Keyboard Shortcuts" in the Classic BLock. Also remove Alt+Shift+Z in the Classic Block as it conflicts with the Block Editor.

Fixes #45365.

TinyMCE: Run the "wp_editor_settings" and "disable_captions" filters for the Classic block. Fixes possible regressions in plugins that use these filters, also plugins that use them to add filters for the buttons, external plugins, etc.

Fixes #45348.

About Page: Initial About Page design and strings for 5.0.

Props @pixelverbieger, @ocean90, @karmatosed, @pento, @boemedia, @lonelyvegan, @sami.keijonen, @TimothyBlynJacobs, @xkon, @afercia, @laurelfulford, @joostdevalk, @ipstenu, @matveb, @joen, @tinkerbelly, @chanthaboune, @kjellr, @alexislloyd, @melchoyce.
See #45178.

Upgrade/Install: Split `Sample Page`, `Hello World`, and `Privacy Policy` content.

[43820] converted the content to blocks, but included block markers in the translateable strings, which made translations difficult to do accurately.

Props desrosj, dd32, ocean90.
See #45151.

Twenty Sixteen: Update theme’s wide image styles to include Image Blocks

Twenty Sixteen includes functionality and styles that make full-size images extend wider than the content when they are added to posts, and appear below the post meta. This update adds the same behavior to image blocks and their captions.

Fixes: #45380.

i18n: Remove the `wp_get_jed_locale_data()` function.

This function was used as a translation workaround in the Gutenberg plugin, it has been replaced in core with the `wp_set_script_translations()` functionality, instead.

See #45111.

Updating Twenty Nineteen, our new default theme for 2019, set for 5.0.

This update changes the following: 

- Fix JS errors in customizer caused by menu scripts
- Fix footer menu spacing
- Fix pullquote block borders to follow Gutenberg’s described style
- Fix editor-only styles so they don't appear on the frontend when not needed
- Fix search field widget width on mobile
- Fix :visited .button link colors
- Fix Block toolbar position in the editor
- Fix off-canvas mobile menu to prevent text from overflowing
- Improve column block formatting for the editor and frontend
- Improve CSS optimization for selectors that add `dashes` to multi-level lists
- Improve editor font sizes to use pixels over ems
- Improve styles for galleries in the Classic Editor block
- Improve priority+ more-menu threshold to allow more space for menu-items
- Improve logo size on mobile devices
- Improve customizer color options to present a single, unified color option
- Improve print stylesheet for better spacing and colors
- Add more color options to Gutenberg editor 

Initial development occurred on GitHub. See: https://github.com/WordPress/twentynineteen

Props allancole, karmatosed, kjellr, yingling017, mrasharirfan, milana_cap, fabiankaegy, westonruter, jorbin, netweb, b-07, khleomix, audrasjb, nielslange, mmaumio, richsalvucci, littlebigthing, dimadin, joyously, anevins, peterwilsoncc, dannycooper, iCaleb, siriokun, technosiren, travel_girl, azchughtai, ianbelanger, nadim1992, ismailelkorchi, nativeinside, chetan200891, grapplerulrich, ocean90, joshfeck, frankew, AbdulWahab610, mendezcode, eliorivero, melchoyce, joen, laurelfulford, mdawaffe, kraftbj, dsmart, nao, mayukojpn, enodekciw, ketuchetan, atanasangelovdev, poena, sharaz, artisticasad, mukesh27, burhandodhy, crunnells, aprakasa, themeroots, imonly_ik, tlxo, youthkee, brentswisher, smyoon315, mrahmadawais, desideveloper, Kau-Boy, mor10, mikeyarce, dingo_bastard

REST API: Include fields with null schema in `get_fields_for_response()`.

In [43736], we prevented rendering fields when not present in `?_fields=`. However, because `get_fields_for_response()` is dependent on `get_item_schema()`, any custom fields registered with a null schema would be incorrectly excluded from the response. Because the REST API permits a null schema for `register_rest_field()`, those fields should be included in the available fields for a response.

Fixes #45220.

Post WordPress 5.0 Beta 5 version bump.

WordPress 5.0 Beta 5.

Build Tools: Minify the package CSS when building.

CSS coming from the `@wordpress` packages wasn't being minified in the build. This had the noteable side effect of causing RTL CSS to not be loaded when `SCRIPT_DEBUG` was set to `false`.

Props websupporter.
See #45330.

Updating Twenty Nineteen, our new default theme for 2019, set for 5.0.

This update changes the following: 

- Improve menu UI to support keyboard navigation in both directions
- Improve more-menu-link visibility when no menu items are hidden
- Improve text-selection custom colors for better contrast and legibility
- Improve support for sticky toolbars in the editor
- Improve table element fonts
- Add .button class support 
- Remove translation escaping
- Fix menu JS to prevent unused touched event listeners
- Fix duplicate more-menu-link issue on selective refresh in the customizer
- Fix editor font-weights for headings
- Fix search form input style
- Fix nested blockquote styles
- Fix download block button style when download text stretches more than one line
- Fix audio block centering issue
- Fix align-full blocks in the editor so they don’t create horizontal scrollbars
- Fix editor to prevent Gutenberg's meta boxes area from overlapping the content

Initial development occurred on GitHub. See: https://github.com/WordPress/twentynineteen

Props allancole, karmatosed, kjellr, yingling017, mrasharirfan, milana_cap, fabiankaegy, westonruter, aaronjorbin, ntwb, b-07, khleomix, audrasjb, nielslange, mmaumio, richsalvucci, littlebigthing, dimadin, joyously, anevins12, peterwilsoncc, DannyCooper, WPprodigy, siriokun, briannaorg, 00travelgirl00, shahjehanali1, ianbelanger79, nadim1992, Ismail-elkorchi, nativeinside, iamchetanp, grappler, ocean90, joshfeck, frankew, abdulwahab610, mendezcode, eliorivero, melchoyce, jasmussen, laurelfulford, mdawaffe, kraftbj, dereksmart, naokomc, mayukojpn, enodekciw, chetansatasiya, ketuchetan, atanas-angelov-dev, carolinan, sharazghouri, artisan-asad, mukeshpanchal27, mukesh27, burhandodhy, @crunnells, aryaprakasa, tlxo, themeroots, whizbangik, yingles, tlxo, youthkee, brentswisher, smy315, ahmadawais, desi-developer, 2ndkauboy, mor10.

Block Editor: Update @wordpress dependencies to match Gutenberg 4.4.0

Updates packages: annotations, api-fetch, block-library, blocks, components, compose, core-data, data, date, edit-post, editor, element, format-library, i18n, list-reusable-blocks, notices, nux, plugins, rich-text, viewport

Updates changed dependencies in script-loader.php

Upgrades React from 16.5.2 to 16.6.3

See #45145

Tests: Update a test that relied on the Hello Dolly plugin version.

[43900] changed the plugin version, causing a unit test failure.

See #45345.

Block Editor: Load TinyMCE inline scripts later.

Previously, the TinyMCE inline scripts were added on the `init` action in the block editor. In the classic editor, however, these scripts are loaded when the TinyMCE window is printed, and some plugins rely on them being loaded later, so they can attach to the appropriate filters.

See #45338.

Hello Dolly: Hide the lyrics in the block editor.

I'm sorry, Hello Dolly. You're my favourite plugin, but the way you output your lyrics doesn't play nicely with the block editor, particuarly on mobile devices.

This isn't Farewell Dolly, you're still on every other admin page, and I know you'll come back better and stronger.

Props joen.
See #45345.

Nav Menus: Fix a PHP 7.3 error when switching themes.

When switching themes, `wp_map_nav_menu_locations()` is used to ensure nav menus are placed in the relevant menu location. Occasionally, menus are registered to locations with numeric slugs, rather than strings. `wp_map_nav_menu_locations()` assumed it would be the latter, and ran `stripos()` on those numeric slugs. This behaviour is deprecated in PHP 7.3.

As this is the last known PHP 7.3 incompatibility, this commit also removes PHP 7.3 from Travis' `allowed_failures` list.

Props desrosj, jorbin.
See #45018.

I18N: Fix warnings in JavaScript translations.

Fixes an undefined index PHP warning in the load_script_textdomain function and a non-interrupting JS error when registering a domain which has no translations.

Props omarreiss, ocean90, georgestephanis.
Fixes #45256.

REST API: Avoid using 'parent' as path argument name for autosaves.

When 'parent' is set as the path argument name, it gets passed down through to the `create_item()` method and can erroneously reset the 'parent' value on the post itself. Instead, we rename the argument to 'id' and replicate the revision controller's `get_items_permissions_check()` to instead reference 'id'.

Also ensures revision query params (of which there are many) aren't exposed as the query params for autosaves (of which there are two).

Props TimothyBlynJacobs.
See #43316.

Post WordPress 5.0 Beta 4 version bump.

WordPress 5.0 Beta 4.

Script Loader: Fix an error introduced in [43893].

`wp_common_block_scripts_and_styles()` should only exit early if we're in the admin and the current screen isn't the block editor.

See #45302.

Scripts: Fix a PHP error in admin-ajax calls.

When making an ajax request, `wp_enqueue_registered_block_scripts_and_styles()` checked if `is_admin()` was true before accessing `$current_screen`, rather than checking if `$current_screen` was defined. This is usually fine, execept for in ajax requests.

Props ocean90, foreverpinetree, pento.
See #45203.

Updating Twenty Nineteen, our new default theme for 2019, set for 5.0.

This update applies the following changes:

- Improve menu UI to support keyboard, click and touch interactions
- Improve variable scoping and js performance in menu interaction javascript
- Improve custom-colors for selected text, buttons and menu hover styles
- Improve margins structure for more consistency between editor and frontend
- Improve discussion avatars for simpler wording and better performance
- Improve fonts in list widgets and list blocks 
- Improve comment responsive spacing and avatar display
- Improve various block styles to make them consistent between the editor and frontend
- Add tabbed browsing support for ie11
- Add backwards compatibility support for older versions of WordPress
- Add fallback styles for older versions of WP where Gutenberg is activated and then deactivated (backwards compatibility)
- Add `sizes` attribute for featured images to improve responsive performance
- Add focus-within polyfill
- Add a footer menu for secondary page links
- Fix editor styles to prevent conflicts with plugins that add meta boxes to the editor
- Fix columns block issues on small screens
- Fix empty-space font text cursor issue in Gutenberg editor
- Fix RTL floating styles so that left/right floats are honored
- Fix cover image block margins/padding
- Fix invalid rgba style
- Fix php warning when returning attributes
- Fix gallery widget margins to improve gallery grids
- Fix .entry-content selectors to prevent shortcodes, plugins and other unknown content from breaking the layout
- Remove translation escaping to follow code standards in previous default themes
- Remove custom color output in the fronten header when default color is selected
- Remove fly-out sub-sub-sub-menu behavior on desktop to prevent sub-menus from falling off the screen
- General code clean up and coding standards improvements

Initial development occurred on GitHub. See: https://github.com/WordPress/twentynineteen

Props allancole, karmatosed, kjellr, yingling017, mrasharirfan, milana_cap, fabiankaegy, westonruter, aaronjorbin, netweb, b-07, khleomix, blowery, dereksmart, jasmussen, audrasjb, nielslange, mmaumio, dimadin, joyously, anevins12, peterwilsoncc, dannycooper, icaleb, siriokun, technosiren, travel_girl, azchughtai, ianbelanger, nadim1992, ismailelkorchi, nativeinside, chetan200891, icaleb, grapplerulrich, ocean90, joshfeck, frankew, abdulwahab610, mendezcode, eliorivero, melchoyce, joen, laurelfulford, mdawaffe, kraftbj, dsmart, mukeshpanchal27, burhandodhy, crunnells, Ismail-elkorchi, aryaprakasa, @tlxo, @themeroots, @whizbangik, @yingles, @youthkee, @brentswisher, @smy315, @ahmadawais, @desi-developer.

Block Editor: Update @wordpress dependencies to the latest version matching Gutenberg 4.3.0

- Update the editor,edit-post,components,block-library,nux and list-reusable blocks packages
 - Also add a missing wp-date dependency to the editor script

Props atimmer
See #45145.

Fix linting after [43889].

See #45264.

Block Editor: Fix the TinyMCE `wordpress` plugin to handle hiding/showing of toolbars in the classic block. Change the classic block toolbar to use the (now fixed) `wp_adv` button.

Fixes #45264.

Block Editor: A little cleanup to `render_block()`. Always normalize `$block['attrs']` to array in `'render_block'` filter.

See #45145.

Docs: Future-proof comments referencing 5.0 TODOs.

Some Customizer-related files contain inline comments referencing work to do for #42364 for 5.0. Those comments are now outdated as #42364 was moved to the 5.1 milestone.

Props dlh.
See #45115.

Build Tools: Add non-minified `@wordpress` scripts to the build output.

Props atimmer.
See #45156.

Block Editor: Hide the Custom Fields meta box option if that meta box has been removed.

Some plugins remove the Custom Fields meta box, particularly when they provide functionality that replaces it. The block editor would correctly not display this meta box in these circumstances, but it still showed the option to display or hide it.

Props pento, noisysocks.
See #45282.

Block Editor: Update `@wordpress` dependencies to the latest version.

Changes of note:
- Includes the new Annotations API package.
- `wp-polyfill-ecmascript.js` is renamed to `wp-polyfill.js`.
- `strip_dynamic_blocks()` has been removed in favour of `excerpt_remove_blocks()`.
- The PHP block parser is now syncing from the `block-serialization-default-parser` package.
- `do_blocks()` uses the new parser.
- The `do_block` filter has been removed from `do_blocks()`, in favour of a `render_block` filter in `render_block()`.

See #45145, #45190, #45264, #45282.

Tests: Fix tests broken in PHP 5.x after [43879].

See #45290.

Meta Boxes: Add the `block_editor_meta_box_hidden_fields` action.

Lacking an appropriate action in the classic editor, plugins that add meta boxes have historically hooked into various actions in order to add hidden input fields.

This change also adds backwards compatibility for two of the most common: `edit_form_after_title`, and `edit_form_advanced`.

Props pento, danielbachhuber.
See #45283.

Tests: Fix a failing test after [43879].

See #45290.

Block Editor: Prevent the meta box form from being accidentally submitted.

Meta boxes are loaded inside a wrapper form, that the block editor submits as part of the saving process. It shouldn't be submitted manually.

See #45284.

Formatting: Ensure `wpautop()` isn't run on content generated from blocks.

As `do_blocks()` is run before `wpautop()` in `the_content` filter, we can remove in a Just In Time fashion, before that filter is run.

After `wpautop()`s original priority has passed, we can re-add it in a Just Too Late fashion, to ensure it's available if `the_content` filter is run multiple times on a page load.

Props pento, nerrad.
Fixes #45290.

I18N: Set translations for all WordPress packages scripts.

Calls `wp_set_script_translations` for all packages scripts that have translations. Also correctly sets the domain on the translations.

Props omarreiss, pento, ocean90.
Fixes #45161.

Script Loader: Ensure default packages are registered when loaded via load-scripts.php.

Props CantoThemes, ocean90.
See #45271.

Twenty Seventeen: Fix issues with theme's Gutenberg support.

A handful of issues were missed in Twenty Seventeen's Gutenberg support, added in #45045. This commit includes the following fixes:

* Update editor placeholder text to use the correct font family.
* Center text and bullets in list-based widget blocks, when block itself is centered.
* Include non "image" variations of the Cover block classes `.wp-block-cover` and `.wp-block-cover-text` in the styles.
* Add spacing underneath the Media & Text block, but make sure the final paragraph in the block doesn't add too much space.
* Simplify selectors used to set editor width to just `.wp-block`.
* Prevent margin from theme's editor-style.css from interfering with editor alignment. 
 
Props pento, davidakennedy.
Fixes #45246.

Twenty Sixteen: Fix issues with theme's Gutenberg support.

A handful of issues were missed in Twenty Sixteen's Gutenberg support, added in #45044. This commit includes the following fixes:

* Center text and bullets in list-based widget blocks, when block itself is centered.
* Correct styles for the editor placeholder text, so it's not inheriting a darker gray from the theme's CSS. 
* Include non "image" variations of the Cover block classes `.wp-block-cover` and `.wp-block-cover-text` in the styles.
* Reset Cover blocks as `display: flex` when they are centered, to maintain their original appearance.
* Add spacing underneath the Media & Text block, but make sure the final paragraph in the block doesn't add too much space.
* Simplify selectors used to set editor width to just `.wp-block`.
* Prevent margin from theme's editor-style.css from interfering with editor alignment. 
 
Props pento, davidakennedy.
Fixes #45245.

Twenty Fifteen: Fix issues with theme's Gutenberg support.

A handful of issues were missed in Twenty Fifteen's Gutenberg support, added in #45043. This commit includes the following fixes:

* Center text and bullets in list-based widget blocks, when block itself is centered.
* Add a margin to blocks that are aligned to the left or to the right, to create space.
* Include non "image" variations of the Cover block classes `.wp-block-cover` and `.wp-block-cover-text` in the styles.
* Add spacing underneath the Media & Text block, but make sure the final paragraph in the block doesn't add too much space.
* Simplify selectors used to set editor width to just `.wp-block`.
* Prevent margin from theme's editor-style.css from interfering with editor alignment. 

Props pento, davidakennedy.
Fixes #45244.

Twenty Fourteen: Fix issues with theme's Gutenberg support.

A handful of issues were missed in Twenty Fourteen's Gutenberg support, added in #45042. This commit includes the following fixes:

* Update editor placeholder text to use the correct font family.
* Center text and bullets in list-based widget blocks, when block itself is centered.
* Remove unnecessary spacing from the Columns block.
* Add spacing underneath the Media & Text block, but make sure the final paragraph in the block doesn't add too much space.
* Include non "image" variations of the Cover block classes `.wp-block-cover` and `.wp-block-cover-text` in the styles.
* Simplify selectors used to set editor width to just `.wp-block`.

Props pento, davidakennedy.
Fixes #45243.

Twenty Thirteen: Fix issues with theme's Gutenberg support.

A handful of issues were missed in Twenty Thirteen's Gutenberg support, added in #45041. This commit includes the following fixes:

* Center text and bullets in list-based widget blocks, when block itself is centered.
* Prevent full and wide aligned blocks from getting wider than Twenty Thirteen's design.
* Prevent wide aligned blocks from getting too wide, as they can seem out of proportion with the full aligned blocks.
* Make sure full and wide blocks display at the correct width in the editor.
* Include non "image" variations of the Cover block classes `.wp-block-cover` and `.wp-block-cover-text` in the styles.
* Make sure wide and full aligned Table blocks span the available width on the front end.
* Add spacing underneath the Media & Text block, but make sure the final paragraph in the block doesn't add too much space.
* Simplify selectors used to set editor width to just `.wp-block`.


Props pento, davidakennedy.
Fixes #45242.

Twenty Twelve: Fix issues with theme's Gutenberg support.

A handful of issues were missed in Twenty Twelve's Gutenberg support, added in #45040. This commit includes the following fixes:

* Update editor placeholder text to use the correct font family.
* Center text and bullets in list-based widget blocks, when block itself is centered.
* Include non "image" variations of the Cover block classes `.wp-block-cover` and `.wp-block-cover-text` in the styles.
* Add spacing underneath the Media & Text block, but make sure final paragraph in the block doesn't add too much space.
* Simplify selectors used to set editor width to just `.wp-block`.


Props pento, davidakennedy.
Fixes #45240.

Twenty Eleven: Fix issues with theme's Gutenberg support.

A handful of issues were missed in Twenty Eleven's Gutenberg support, added in #45039. This commit includes the following fixes:

* Center text and bullets in list-based widget blocks when block itself is centered.
* Include non "image" variations of the Cover block classes `.wp-block-cover` and `.wp-block-cover-text` in the styles.
* Add spacing underneath the Media & Text block, but make sure final paragraph in the block doesn't add too much space.
* Simplify selectors used to set editor width to just `.wp-block`.
* Prevent margin from theme's editor-style.css from interfering with editor alignment. 

Props pento, davidakennedy.
Fixes #45239.

Twenty Ten: Fix issues with theme's Gutenberg support.

A handful of issues were missed in Twenty Ten's Gutenberg support, added in #45038. This commit includes the following fixes:

* Update editor placeholder text to use the correct font family and size.
* Remove unnecessary spacing from the Columns block.
* Include non "image" variations of the Cover block classes `.wp-block-cover` and `.wp-block-cover-text` in the styles.
* Add spacing underneath the Media & Text block.
* Simplify selectors used to set editor width to just `.wp-block`.

Fixes #45238.

Bundled Themes: Add theme support for responsive embeds

Add `add_theme_support( 'responsive-embeds' );` to all of the responsive default themes as part of their Gutenberg support. This makes sure any embeds coming from the new block-based editor maintain their aspect ratios at different screen sizes.

Fixes #45274.

TinyMCE:

- Fix parsing of the init array in script-loader.
- Do not JSON encode the options object when outputting it from PHP.
- Remove JSON decoding of TinyMCE's `style_formats` option.

Fixes #45221.

Tests: Skip symlinked theme file tests if the links could not be created, or if `symlink()` is not available

Merges [42812,42819] to the 5.0 branch.

Props SergeyBiryukov.
Fixes #43508.

Post WordPress 5.0 Beta 3 version bump.

WordPress 5.0 Beta 3.

Meta Boxes: Add curly brackets missed in [43861].

This was causing the custom meta box to be incorrectly added to post types that don't support it.

Props ocean90, epointal.
Fixes #45257,

REST API: Prevent duplicate firing of `rest(_after)?_insert_attachment` actions.

Props danielbachhuber, peterwilsoncc.
Fixes #45269.
See #42864.

Build Tools: Update the `@wordpress` packages.

This brings support for the custom fields meta box to the block editor.

The `webpack` and `copy-webpack-plugin` packages have also been updated.

See #45145.
Fixes #45257.

Importing Twenty Nineteen, our new default theme for 2019, set for 5.0.

Let Gutenberg shine with this simple, fast, and powerful theme. Initial development occurred on GitHub. See: https://github.com/WordPress/twentynineteen

Props allancole, karmatosed, kjellr, yingling017, mrasharirfan, milana_cap, fabiankaegy, westonruter, aaronjorbin, netweb, b-07, khleomix, blowery, dereksmart, jasmussen, audrasjb, nielslange, mmaumio, dimadin, joyously, anevins12, peterwilsoncc, dannycooper, icaleb, siriokun, technosiren, travel_girl, azchughtai, ianbelanger, nadim1992, ismailelkorchi, nativeinside, chetan200891, icaleb, grapplerulrich, ocean90, joshfeck, frankew, abdulwahab610, mendezcode, eliorivero, melchoyce, joen, laurelfulford, mdawaffe, kraftbj, dsmart, mukeshpanchal27, burhandodhy, crunnells, Ismail-elkorchi, aryaprakasa.

I18N: Improve JavaScript translation support.

Improves upon [43825] by adding unit tests to cover additional use-cases and changes loading translations to only occur when outputting the script to allow setting translations on dependencies.

Props atimmer, omarreiss, nerrad, swissspidy, ocean90.
Fixes #45103.

Editor: Cast the result of the `default_content`, `default_title`, and `default_excerpt` filters.

If a plugin returns a non-string value (or returns `null`) on these filters, it can cause errors in the block editor. Casting them as a string prevents these errors.

Props dd32.
See #45236.

Block Editor: Remove CodeMirror settings.

CodeMirror is no longer used in the block editor, so we don't need to load the settings.

Props noisysocks.
Fixes #45248.

Block Editor: Don't show back compat or incompatible meta boxes in Options.

Meta boxes that exist for back compat, or that are incompatible with the block editor aren't displayed, so they don't need an option to display or hide them in the Options dialog.

Props noisysocks.
Fixes #45249.

Posts: Remove the slug from Quick Edit for posts that are not `is_post_type_viewable()`.

This is a followup to [43728], which added the same check, but using the `publicly_queryable` option. This behaviour is incorrect for `_builtin` post types, which go by the logic in `is_post_type_viewable()`, instead.

See #43278.

Blocks: Add "Export as JSON" action to the `wp_block` post list screen.

Remove the "Quick Edit" for `wp_block`s, too, as they don't need any of that functionality.

Props noisysocks.
Fixes #45247.

Build Tools: Switch to Node 10.13.0.

Now that Node 10 is the LTS branch, with 10.13.0 as the first LTS release, let's use that for building WordPress.

See #45241.

REST API: Fix array syntax after [43851].

I thought I was writing JavaScript. Alas.

See #45196.

REST API: Regenerate fixure schema after introduction of new endpoints.

This fixture schema ensures `wp-api-generated.js` doesn't change when running tests in local dev environments.

Fixes #45196.

REST API: Restore access to audio/video metadata functions.

Ensures `wp_read_video_metadata()`/`wp_read_audio_metadata()` functions are available when uploading video and audio. Fixes error introduced in [43589].

Props ocean90.
See #43757.

Blocks: Include necessary labels for the 'wp_block' post type.

See #45098

FTP/PemFTP Library: Fix some PHP notices.

- `ftp_base::glob()` used `each()`, which is deprecated as of PHP 7.2.
- `ftp_base::fget()` was missing the decleration of its third parameter, `$rest`.

Props itowhid06.
See #44489.

Build Tools: Update the `@wordpress` packages.

Trunk now matches Gutenberg 4.2 RC1.

See #45145.

l10n: Avoid calling `is_user_logged_in()` in `determine_locale()`.

`is_user_logged_in()` is a pluggable function, and loaded after plugins are loaded. If a plugin calls `__()` too early, `is_user_logged_in()` is missing and WordPress will fatal. `get_user_locale()` already handles this scenario for us, so it's safe to rely on exclusively.

See #44758.
Fixes #45235.

Posts WordPress 5.0 Beta 2 version bump.

WordPress 5.0 Beta 2.

Build Tools: Update `@wordpress` packages.

See #45145.

Importing Twenty Nineteen, our new default theme for 2019, set for 5.0.

Let Gutenberg shine with this simple, fast, and powerful theme. Initial development occurred on GitHub. See: https://github.com/WordPress/twentynineteen

Props allancole, karmatosed, kjellr, yingling017, mrasharirfan, milana_cap, fabiankaegy, westonruter, aaronjorbin, netweb, b-07, khleomix, blowery, dereksmart, jasmussen, audrasjb, nielslange, mmaumio, dimadin, joyously, anevins12, peterwilsoncc, dannycooper, icaleb, siriokun, technosiren, travel_girl, azchughtai, ianbelanger, nadim1992, ismailelkorchi, nativeinside, chetan200891, icaleb, grapplerulrich, ocean90, joshfeck, frankew, abdulwahab610, mendezcode, eliorivero, melchoyce, joen, laurelfulford, mdawaffe, kraftbj, dsmart.

Tests: Fix failing unit tests caused by [43840].

See #45145.

Build Tools: Upgrade `@wordpress` packages to the latest version.

This also includes the new `@wordpress/format-library` and `@wordpress/notices` packages.

`package-lock.json` has been completely regenerated in this commit.

See #45145.

Meta boxes: Don't show the block editor incompatiblity message when it doesn't apply.

We should only be showing this message in the classic editor interface, for meta boxes that are marked as being incompatible with the block editor.

Fixes #45207.

Meta boxes: Don't assume that callback args are an array.

While the documentation for `add_meta_box()` specifices that `$callback_args` should be an array, this has never been enforced, and we have workarounds in place for when it's passed as something other than an array.

Rather than break sites that are passing unexpected data, we can quietly just allow for it, instead.

Props johnjamesjacoby, birgire.
Fixes #45206.

Block Editor: Fix meta boxes not showing.

The block editor needs to duplicate the classic meta box behaviour, so it can extract the registered meta boxes, and import them into the block editor.

To match the classic editor behaviour as closely as possible, this moves the relevant code from the classic editor, into a new function, so it can be called by both.

Props pento, peterwilsoncc.
Fixes #45172.

Build Tools: Add an npm script shortcut to run grunt.

Rather than needing to install grunt globally, this allows running grunt from `node_modules`, instead.

`npm run grunt ...` is effectively the equivalent of running `grunt ...`.

Props andrew.taylor.
See #45214.

Build Tools: Revert [43826] and [43824].

Grabbing the packages directly from the Gutenberg repo was an interesting experiment, but it causes significant workflow issues, particular for folks using Windows.

See #45145.

REST API: Improve performance by avoiding `call_user_func()`.

The `get_compact_response_links()` method was introduced in WP 4.5, and this conditional is no longer necessary.

Props schlessera, timothyblynjacobs.
Fixes #45189.

Block Editor: Preload `wp/v2/media` with OPTIONS for caps check.

Also introduces a `block_editor_preload_paths` filter for plugins and themes to preload additional data.

Props imath, mattheu.
Fixes #45194.

php7.3 compatibility: Fix compact throwing notices for multisite

In PHP 7.3, the compact() function has been changed to issue an E_NOTICE level error if a passed string refers to an unset variable. In previous versions of PHP, this notice was silently skipped. The full RFC can be viewed here: https://wiki.php.net/rfc/compact

By initializing these variables, they can be compacted.

Previously [43819].
See #44416.
Props desrosj.

Script Loader: Add translator comments and remove textdomains.

The inline script for `wp-date` incorrectly included a textdomain, and lacked translator comments.

Props mukesh27.
Fixes #45191, #45162.

Meta Boxes: Fix error when a meta box is rendered with a static method callback.

When `WP_DEBUG` is set, ensure that a static method callback is passed to `ReflectionMethod`, instead of `ReflectionFunction`.

Props DrewAPicture.
Fixes #45192.

Accessibility: Media: Improve the usage of a few label elements in the media templates.

Label elements should only be used for labelable elements.
- `Uploaded By` and `Uploaded To` aren't form controls and shouldn't be associated with labels
- changes the labels for media source, alternate sources, poster image, and tracks to solve a layout issue and explicitly associate the labels to their form fields (previously, the labels were wrapping also the Remove buttons)

Merges [42444] to the 5.0 branch.

Props Presskopp, afercia.
Fixes #38759, #40468.

Tests: Use `DIR_TESTDATA` in `test_wp_set_script_translation()`.

`__DIR__` is not available in PHP 5.2.x.

See #45103.

Docs: Link to the "Conditional Tags" article in the Theme Developer Handbook from the descriptions for a variety of core conditional tag functions.

These notations largely serve to direct consumers (of both the source and the parsed code reference) to extended information on individual and related conditional tags throughout WordPress. The changeset also standardizes corresponding DocBlock summaries to use third-person singular verbs.

Notations have been added for the following functions:

* comments_open()
* email exists()
* has_excerpt()
* has_post_thumbnail()
* has_tag()
* in_category()
* in_the_loop()
* is_404()
* is_active_sidebar()
* is_active_widget()
* is_admin()
* is_admin_bar_showing()
* is_archive()
* is_attachment()
* is_author()
* is_blog_installed()
* is_category()
* is_comments_popup()
* is_date()
* is_day()
* is_dynamic_sidebar()
* is_feed()
* is_front_page()
* is_home()
* is_local_attachment()
* is_main_query
* is_month()
* is_multi_author
* is_new_day()
* is_page()
* is_page_template()
* is_paged()
* is_plugin_active()
* is_plugin_active_for_network()
* is_plugin_inactive()
* is_plugin_page()
* is_post_type_archive()
* is_preview()
* is_rtl()
* is_search()
* is_single()
* is_singular()
* is_sticky()
* is_tag()
* is_tax()
* is_taxonomy_hierarchical()
* is_time()
* is_trackback()
* is_user_logged_in()
* is_year()
* pings_open()
* post_type_exists()
* taxonomy_exists()
* term_exists()
* username exists()
* wp_attachment_is_image()
* wp_script_is() 

Merges [42710] to the 5.0 branch.

Props janalwin.
Fixes #43254.

Build tools: Fix build after [43824].

Props omarreiss.
See #45145.

I18N: Add JavaScript translation support.

Adds the `wp_set_script_translations` function which registers translations for a JavaScript file. This function takes a handle, domain and optionally a path and ensures JavaScript translation files are loaded if they exist.

Props atimmer, omarreiss, nerrad, swissspidy, ocean90.
Fixes #45103.

Build tools: Clone and build from packages repo.

Instead of requiring the packages individually this commit changes it so the packages are used from the packages repository (gutenberg). This is a solution that makes updating the packages easier, as long as we don't have a monorepo to manage both WordPress & the JavaScript packages together.

Props youknowriad, gziolo, omarreiss, herregroen.
See #45145.

Post WordPress 5.0 Beta 1 version bump.

WordPress 5.0 Beta 1.

Bundled Themes: Remove languages folder with POT file from Twenty Nineteen.

POT files are no longer required.

Upgrade/Install: Convert `Sample Page`, `Hello World`, and `Privacy Policy` to block content.

Props desrosj, garrett-eclipse, danielbachhuber.
Fixes #45151.

php7.3 compatibility: Fix compact throwing notices

In PHP 7.3, the compact() function has been changed to issue an E_NOTICE level error if a passed string refers to an unset variable. In previous versions of PHP, this notice was silently skipped. The full RFC can be viewed here: https://wiki.php.net/rfc/compact

This fixes all unit tested code that uses compact.

Props desrosj.
Fixes #44416.

Scripts: Add a missing date format to the `wp-date` config.

`wp-date` recently added the `datetimeAbbreviated` format, but the config wasn't sending it on page load.

Fixes #45158.

Build tools: Build webpack dev in `grunt build`.

For the WordPress zip we need both the minified and non-minified files. This is because of `SCRIPT_DEBUG`. So in `grunt build` we need to do both `grunt webpack:prod` and `grunt webpack:dev`.

Props bordoni.
Fixes #45156.

Block Editor: Remove some errant debugging included in [43815].

Props bordoni.
See #45037.

Editor: Minor bug fixes.

Change the default layout slightly, and tweak the HTML stored in `post_content`.

Props matveb, karmatosed, joen, youknowriad, aduth, iseulde, pento, EphoxJames, mkaz, jnylen0, notnownikki, lonelyvegan, chopinbach, njpanderson, mimo84, intronic, westonruter, mcsf, dmsnell, afercia, paulwilde, mitogh, codebykat, mrahmadawais, kopepasah, circlecube, adamsilverstein, timmydcrawford, ephox-mogran, nbachiyski, JDGrimes, laurelfulford, Soean, mapk, sirjonathan, j-falk, ryelle, helen, netweb, lamosty, willybahuaud, maurobringolf, jorbin, spocke, androb, annaharrison, Afraithe, georgeh, matt, melchoyce, nitrajka, sirreal, babbardel, arush, martinlugton, iandunn, oyously, rileybrook, azaozz, folletto, ianstewart, johnpixle, clorith, joedolson, ipstenu, mrwweb, diegoliv, jeffpaul, lukecavanagh, shaunandrews, hugobaeta, jjj, mizejewski, buzztone, jdembowski, webdevmattcrom, GaryJones, jasonagnew, dd32, ieatwebsites, gma992, swissspidy, dixitadusara, ameeker, stagger-lee, jblz, nicbertino, rahmohn, vladanost, gziolo, lancewillett, lynneux, betsela, fuyuko, msdesign21, thrijith, chanthaboune, Cloud887, hblackett, vishalkakadiya, c-shultz, nfmohit, noisysocks, omarreiss, hedgefield, hideokamoto, mirucon, nosolosw, DannyCooper, burhandodhy, zebulan, benjamin_zekavica, danielbachhuber, jorgefilipecosta, ajitbohra, bph, ChrisVanPatten, dixitadusara, antpb, mikehaydon, jahvi, floriansimeth, Mathiu, amedina, diegoreymendez, etoledom, caxco93, yoavf, welcher, bobbingwide, jonsurrell, notlaura, ocean90, eliorivero, wpscholar, Shelob9, travislopes, earnjam, designsimply, johnwatkins0, dfangstrom, igorsch, jaswrks, daniloercoli, rianrietveld, dimadin, SergioEstevao, dlocc, tinkerbelly, schlessera, sumobi, kjellr, ireneyoast, hypest, tfrommen, intronic, johnny5, samikeijonen, bpayton, atimmer, Rahmon, tg-ephox, nerrad, talldan, Xyfi.

See #45037.

Themes: Document the new theme features being added.

The `add_theme_support()` inline docs now includes the features that the block editor adds.

Props desrosj.
See #45134.

KSES: Allow the `download` attribute on `<a>` tags.

To avoid this being a vector for bypassing the filetypes that are allowed to be uploaded, this attribute is only allowed to be added without a value.

Props kalpshit, arshidkv12, welcher, peterwilsoncc, marina_wp, pento.
See #44724.

Styles: Add helper functions for loading block styles.

Blocks are able to register styles that used in the editor and the frontend, or only in the editor. These functions ensure the correct styles are loaded in the correct place.

See #45065.

Meta: Allow empty strings to be set by Custom Fields meta box.

Because the REST API allows meta keys to have empty values, the Custom Fields meta box should permit the same behavior.

Props charlestonsw, soulseekah.
Fixes #43559.

Embeds: Filter HTML response in oEmbed proxy controller.

Adapts the response from `WP_oEmbed_Controller::get_proxy_item()` so that the response is correctly filtered and embeds work properly in JavaSccript editors. Introduces new `get_oembed_response_data_for_url()` function for preparing internal oEmbed responses.

Props danielbachhuber, imath, swissspidy.
Fixes #45142.

Bundled Theme: Make twentynineteen the default theme.

After [43808], we can now make twentynineteen the default theme. Twentyseventeen has been a great default, but 5.0 and twentynineteen is guten.

Fixes #45152.

Importing Twenty Nineteen, our new default theme for 2019, set for 5.0.

Let Gutenberg shine with this simple, fast, and powerful theme. Initial development occurred on GitHub. See: https://github.com/WordPress/twentynineteen

Props allancole, karmatosed, kjellr, yingling017, mrasharirfan, milana_cap, fabiankaegy, westonruter, aaronjorbin, netweb, b-07, khleomix, blowery, dereksmart, jasmussen, audrasjb, nielslange, mmaumio, dimadin, joyously, anevins12.

Dashboard: Remove the Try Gutenberg callout.

Block or block not. There is no try.

Props mukesh27.
See #45063.

Blocks: Fix coding standards introduced in [43804].

Props Presskopp, swissspidy.
See #45098

REST API: Add endpoints for blocks.

`WP_REST_Block_Renderer_Controller` allows rendering of server-side rendered blocks, whilst `WP_REST_Blocks_Controller` allows retrieving of reusable blocks.

Props desrosj, danielbachhuber, pento.
See #45065.

Blocks: Add the reusable block post type, `wp_block`.

See #45098.

Scripts: `wp-url` is a dependency of `wp-api-fetch`.

See #45065.

Script Loader: Fix metadata being registered as an inline script.

[43723] included script metadata for the `wp-polyfill` script that was being registered as an inline script.

See #45065.

Build: Update the `@wordpress/editor` package.

The `@wordpress/editor` wasn't upgraded to the correct version in [43789].

This commit includes changes from the `@wordpress/block-library` upgrade in [43789], that weren't copied to the correct location in core.

This also regenerates the `package-lock.json` in Linux, which the build server requires.

See #45145.

Twenty Seventeen: Add styles and support for the new block-based editor.

This update adds styles and theme support related to the new block-based editor to enhance the experience of using it with Twenty Seventeen. 

These are the specific changes made to this theme:

* Add blocks.css, to style blocks on the front end, to make sure they match the theme’s existing HTML element styles.
* Add editor-blocks.css to style blocks in the editor, to make sure they match the theme’s existing HTML element styles.
* Add theme support for `editor-styles`, to pull the existing editor stylesheet into the new editor.
* Add theme support for `wp-block-styles`, to load the default block styles on the front end.

Props laurelfulford, ianbelanger, crunnells.
Fixes #45045.

Twenty Sixteen: Add styles and support for the new block-based editor.

This update adds styles and theme support related to the new block-based editor to enhance the experience of using it with Twenty Sixteen. 

These are the specific changes made to this theme:

* Add blocks.css, to style blocks on the front end, to make sure they match the theme’s existing HTML element styles.
* Add editor-blocks.css to style blocks in the editor, to make sure they match the theme’s existing HTML element styles.
* Add theme support for `editor-styles`, to pull the existing editor stylesheet into the new editor.
* Add theme support for `wp-block-styles`, to load the default block styles on the front end.
* Add theme support for `editor-color-palette`, to load a color palette based on the theme’s color scheme into the block-based editor.

Props laurelfulford.
Fixes #45044.

Twenty Fifteen: Add styles and support for the new block-based editor.

This update adds styles and theme support related to the new block-based editor to enhance the experience of using it with Twenty Fifteen. 

These are the specific changes made to this theme:

* Add blocks.css, to style blocks on the front end, to make sure they match the theme’s existing HTML element styles.
* Add editor-blocks.css to style blocks in the editor, to make sure they match the theme’s existing HTML element styles.
* Add theme support for `editor-styles`, to pull the existing editor stylesheet into the new editor.
* Add theme support for `wp-block-styles`, to load the default block styles on the front end.
* Add theme support for `editor-color-palette`, to load a color palette based on the theme’s color scheme into the block-based editor.

Props laurelfulford.
Fixes #45043.

Twenty Fourteen: Add styles and support for the new block-based editor.

This update adds styles and theme support related to the new block-based editor to enhance the experience of using it with Twenty Fourteen. 

These are the specific changes made to this theme:

* Add blocks.css, to style blocks on the front end, to make sure they match the theme’s existing HTML element styles.
* Add editor-blocks.css to style blocks in the editor, to make sure they match the theme’s existing HTML element styles.
* Add theme support for `editor-styles`, to pull the existing editor stylesheet into the new editor.
* Add theme support for `wp-block-styles`, to load the default block styles on the front end.
* Add theme support for `editor-color-palette`, to load a color palette based on the theme’s color scheme into the block-based editor.

Props laurelfulford, crunnells, ianbelanger.
Fixes #45042.

Twenty Thirteen: Add styles and support for the new block-based editor.

This update adds styles and theme support related to the new block-based editor to enhance the experience of using it with Twenty Thirteen. 

These are the specific changes made to this theme:

* Add blocks.css, to style blocks on the front end, to make sure they match the theme’s existing HTML element styles.
* Add editor-blocks.css to style blocks in the editor, to make sure they match the theme’s existing HTML element styles.
* Add theme support for `editor-styles`, to pull the existing editor stylesheet into the new editor.
* Add theme support for `wp-block-styles`, to load the default block styles on the front end.
* Add theme support for `editor-color-palette`, to load a color palette based on the theme’s color scheme into the block-based editor.
* Add theme support and styles for `align-wide`, to allow wide and full alignment styles on the blocks.

Props laurelfulford, ianbelanger.
Fixes #45041.

Twenty Twelve: Add styles and support for the new block-based editor.

This update adds styles and theme support related to the new block-based editor to enhance the experience of using it with Twenty Twelve. 

These are the specific changes made to this theme:

* Add blocks.css, to style blocks on the front end, to make sure they match the theme’s existing HTML element styles.
* Add editor-blocks.css to style blocks in the editor, to make sure they match the theme’s existing HTML element styles.
* Add theme support for `editor-styles`, to pull the existing editor stylesheet into the new editor.
* Add theme support for `wp-block-styles`, to load the default block styles on the front end.
* Add theme support for `editor-color-palette`, to load a color palette based on the theme’s color scheme into the block-based editor.

Props ianbelanger, crunnells, laurelfulford.
Fixes #45040.

Twenty Eleven: Add styles and support for the new block-based editor.

This update adds styles and theme support related to the new block-based editor to enhance the experience of using it with Twenty Eleven. 

These are the specific changes made to this theme:

* Add blocks.css, to style blocks on the front end, to make sure they match the theme’s existing HTML element styles.
* Add editor-blocks.css to style blocks in the editor, to make sure they match the theme’s existing HTML element styles.
* Add theme support for `editor-styles`, to pull the existing editor stylesheet into the new editor.
* Add theme support for `wp-block-styles`, to load the default block styles on the front end.
* Add theme support for `editor-color-palette`, to load a color palette based on the theme’s color scheme into the block-based editor.

Props ianbelanger, laurelfulford.
Fixes #45039.

Twenty Ten: Add styles and support for the new block-based editor.

This update adds styles and theme support related to the new block-based editor to enhance the experience of using it with Twenty Ten. 

These are the specific changes made to this theme:

* Add blocks.css, to style blocks on the front end, to make sure they match the theme’s existing HTML element styles.
* Add editor-blocks.css to style blocks in the editor, to make sure they match the theme’s existing HTML element styles.
* Add theme support for `editor-styles`, to pull the existing editor stylesheet into the new editor.
* Add theme support for `wp-block-styles`, to load the default block styles on the front end.
* Add theme support for `editor-color-palette`, to load a color palette based on the theme’s color scheme into the block-based editor.

Props nielslange, crunnells, laurelfulford.
Fixes #45038.

Meta Boxes: Sync checks for valid meta boxes from `do_meta_boxes()` to `the_block_editor_meta_boxes()`.

See #45112.

Themes: Remove a stray slash and `gutenberg` text domain.

See #45125.

Themes: Introduce responsive embeds support.

Responsive embeds is a way for a theme to opt in to WordPress dynamically scaling the width/height of an embed. When a theme supports responsive embeds, a `wp-embed-responsive` class is added to the `<body>` tag. This information is also presented through the REST API for clients to respect.

Props desrosj.
Fixes #45125.

Build tools: Upgrade @wordpress packages.

Generated using `npm update @wordpress/api-fetch @wordpress/blob @wordpress/block-library @wordpress/blocks @wordpress/components @wordpress/compose @wordpress/core-data @wordpress/data @wordpress/date @wordpress/dom @wordpress/edit-post @wordpress/editor @wordpress/element @wordpress/escape-html @wordpress/list-reusable-blocks @wordpress/nux @wordpress/plugins @wordpress/redux-routine @wordpress/rich-text @wordpress/url @wordpress/viewport`.

See #45145.

Script/Style Dependencies: Make sure that inline scripts for handles without a source are printed.

See [36550] for `WP_Styles`.

Merges [43565] to the 5.0 branch.

Props bpayton.
Fixes #44551.

TinyMCE: remove stray CSS map reference from `skin.min.css`.

Merges [43581] to the 5.0 branch.

Props pross.
Fixes #44785.

Build/Tools: Add PHPCS to the 5.0 branch.

This allows us to apply WordPress Coding Standards rules to new files in the 5.0 branch.

Props netweb.
Fixes #44366.

Build: Update images following [43684].

`grunt-contrib-imagemin` was updated, which included some changes to image minification. Those changes are now applies.

Props netweb.
See #45080.

Build: Updated CSS vendor prefixes following [43684].

`autoprefixer` was updated, which included some vendor prefix changes. Those changes are now applied.

Props netweb.
See #45080.

Build: Ignore the vendor directory during the `jsvalidate:build` task.

Props netweb.
Fixes #45119.

Build: Switch package.json to using tabs for indents.

Merges [42460] to the 5.0 branch.

Props netweb.
Fixes #43075.

KSES: Allow `url()` to be used in inline CSS.

The cover image block uses the `url()` function in its inline CSS, to show the cover image. KSES didn't allow this, causing the block to not save correctly for Author and Contributor users. As KSES does already check each attribute name against an allowed list, we're able to add an extra check for certain attributes to be able to use the `url()` function, too.

Props peterwilsoncc, azaozz, pento, dd32.
See #45067.

Block Editor: Add extra body classes when the block editor is loaded.

See #45037.

Meta Boxes: Add `__back_compat_meta_box` and `__block_editor_compatible_meta_box` flags to meta boxes.

When meta boxes are registered, they can use the `__back_compat_meta_box` and `__block_editor_compatible_meta_box` flags, to show whether this registration just exists for if the classic editor is loaded, and whether this meta box is compatible with the block editor.

When a meta box marks itself as incompatible with the block editor, and `WP_DEBUG` is enabled, a warning will show inside that meta box in the classic editor.

As all core meta boxes have been recreated in the block editor, they can be marked with the `__back_compat_meta_box` flag.

See #45112.

Block Editor: Add helper functions to collect meta box information.

To allow the block editor to render meta boxes, it needs to collect information about how those meta boxes are registered, and format it for the block editor to make use of.

See #45112.

Block Editor: Add an `is_block_editor()` method to `WP_Screen`.

This method allows checking (or setting) whether the block editor is loading on the current screen.

See #45037.

REST API: Render response in user locale with `?_locale=user`.

Introduces new `determine_locale()` function for deciding the proper locale to use for a response. Default value is `get_user_locale()` in the admin, and `get_locale()` on the frontend. Because REST API requests are considered frontend requests, `?_locale=user` can be used to render the response in the user's locale.

Also updates `wp-login.php?wp_lang` implementation to benefit from this abstraction.

Props flixos90, mnelson4, swissspidy, TimothyBlynJacobs.
Fixes #44758.

Revisions: Improve performance of `WP_Text_Diff_Renderer_Table`.

`WP_Text_Diff_Renderer_Table` is used to generate the diff view in revisions, but there were some cases that could cause it to take excessive amounts of time to run.

Some noteable cases include:
- When a large number of new lines were inserted in the middle of the post from one revision to the next.
- When both revisions contain >100 lines.
- When either revision contains a lot of long lines.

In one extreme test case, the diff view took over a minute to generate. With this change, it now takes less than a second.

See #35667.

REST API: Restore Autosaves controller test for multisite.

PHPUnit 3.6.x requires `exclude` and `file` paths to be relative to the checkout root.

PHPUnit 4.0.0+ requires the paths to be relative to the configuration file.

See #45131.

REST API: Limit the scope of wp-admin files required in WP_REST_Attachments_Controller methods.

Narrow the scope of the included wp-admin files loaded for `wp_generate_attachment_metadata()`, `wp_handle_upload()`, `wp_tempnam()`, and `wp_handle_sideload()`. Requires only `wp-admin/includes/file.php` and `wp-admin/includes/image.php` instead of `wp-admin/includes/admin.php`.

Props ocean90, lonelyvegan, soulseekah, pratikthink.
Merges [43589], [43604] to the 5.0 branch.
Fixes #43757.

Help/About: Ensure the space after the period for the 4.9.8 changelog entry is preserved.

Props chetan200891, burhandodhy, swissspidy.
Merges [43622] to the 5.0 branch.
See #44717.

REST API: Handle api-request query parameters with plain permalinks.

When constructing the request URL, ensure that `?` is replaced with `&` when the API root already contains a `?`. Fixes an issue where requests were broken when sites had permalinks set to plain.

Props aduth.
Merges [42965] to the 5.0 branch.
Fixes #42382.

REST API: Include `block_version` on Post `content` object.

The `block_version` denotes which version of Blocks the `post_content` contains. Introduces new `block_version()` function for versioning Blocks.

Props danielbachhuber, birgire.
Fixes #43887.

REST API: Skip Autosaves controller test for multisite.

There's some PHP 5.2 (cough, cough) edge case where paths calculated differently, possibly caused by differing version of PHPUnit.

See #45132, #45131, #43316.

REST API: Introduce Autosaves controller and endpoint.

* Adds `WP_REST_Autosaves_Controller` which extends `WP_REST_Revisions_Controller`.
* Autosaves endpoint is registered for all post types except `attachment` because even post types without revisions enabled are expected to autosave.
* Because setting the `DOING_AUTOSAVE` constant pollutes the test suite, autosaves tests are run last. We may want to improve upon this later.

Props adamsilverstein, aduth, azaozz, danielbachhuber, rmccue.
Fixes #43316.

REST API: Use a truly impossibly high number in User Controller tests.

The `100` number could be valid in certain test run configurations. The `REST_TESTS_IMPOSSIBLY_HIGH_NUMBER` constant is impossibly high for this very reason.

Fixes #45128.

REST API: Ensure rest_url() consistently has leading slash.

`rest_url()` inconsistent addes slashes to the passed path depending on whether the site has pretty permalinks enabled. Apart from being inconsistent, this also caused the unit tests to fail when pretty permalinks are enabled.

Props frank-klein.
Merges [42250] to the 5.0 branch.
Partially reverts [43720].
Fixes #42452. See #41451, #45017.

Deactivate Gutenberg plugin on update to 5.0.

Fixes #45123.

i18n: Remove some translation domains accidentally included in [43762].

See #45110.

REST API: Introduce the `rest_preload_api_request()` function.

This function helps perform multiple REST API requests, for the purpose of preloading data into a page.

See #45110.

Block Editor: Add helper functions for displaying the editor.

`use_block_editor_for_post()` and `use_block_editor_for_post_type()` determine if the block editor should be loaded.

`get_block_categories()` and `get_block_editor_server_block_settings()` provide data be included while the block editor is loading.

See #45110.

General: Extract the code editor settings from `wp_enqueue_code_editor()`.

They're now returned by a new function, `wp_get_code_editor_settings()`, so they can be reused by the block editor.

See #45127.

Build Tools: Copy package JavaScript and CSS into `wp-includes`.

- `grunt webpack:dev` now copies packages JS into `/src/wp-includes/js/dist`, and CSS into `/src/wp-includes/css/dist`.
- `grunt webpack:prod` does the same, but into `/build` instead of `/src`.
- `grunt build` now runs the `webpack:prod` task.

Props atimmer, pento.
Fixes #45119.

i18n: Add the `wp_get_jed_locale_data()` function.

This function formats locale information to be used by Jed.

Props desrosj.
See #45111.

Classic Editor: Disable the wpautop TinyMCE plugin on block posts.

As the block editor adds its own `<p>` tags, disabling the wpautop stops the classic editor from removing them.

See #45113.

REST API: generate a valid fallback URI in wp.api.utils.getRootURL.

When window.location.origin isn't set, correctly insert two slashes between the protocol and host when constructing the fallback URL.

Props abdullahramzan.
Merges [43566] into the 5.0 branch.
Fixes #44764.

REST API: Correct HTTP status code in error for requests to create a duplicate term.

The 409 error code is intended for situations where it is expected that the user will resolve the conflict and resubmit the same request. We use 400 error codes for other routes when a duplicate request is made. The 400 status code tells the user they need to modify their request for it to be successful.

Props shooper.
Merges [42354] to the 5.0 branch.
Fixes #42781. See #41370.

REST API: Fix permissions error message in post statuses controller.

The permissions error message when a request tries to fetch post statuses unauthenticated is incorrect. It was a copy/paste from elsewhere, as indicated by the use of "in this post type" where this is no post type referenced.

Props schlessera.
Merges [42356] to the 5.0 branch.
Fixes #42303.

Script loading: Fix a PHP error introduced in [43753].

See #45065.
Props swissspidy.

Script loading: Fix regression after [43738].

After [43738], TinyMCE would be loaded earlier than before, which
makes filters run at a different time relative to the loading of
TinyMCE. Fix this by calling `wp_print_scripts` at the location where
TinyMCE would previously be inserted as a `<script>` tag in the page.

Props azaozz, omarreiss.
Fixes #45065.

Blocks: Parse blocks when displaying posts.

Posts containing blocks are now correctly handled when displaying on the front end, including dynamic blocks and nested blocks.

See #45109.

Blocks: Introduce the block parser.

The `WP_Block_Parser` class, and the accompanying `parse_blocks()` helper function, can be used to parse an array of blocks out of a content string.

`WP_Block_Parser` is copied from the `@wordpress/block-serialization-default-parser` package. To ensure it stays in sync with the JavaScript parser, changes should be implemented in the package first, then the package version should be upgraded to include the changes.

See #45109.

Media: Pass EXIF data to the `wp_read_image_metadata` filter.

Props desrosj.
Merges [42879] to the 5.0 branch.
Fixes #43624.

Media: In `wp_read_image_metadata()`, rename `$sourceImageType` variable to `$image_type` to match coding standards.

Merges [42878] to the 5.0 branch.
See #43624.

Build/Test Tools: Instruct Git and Subversion to ignore Composer's `vendor` directory.

Props netweb.
Merges [42405] to the 5.0 branch.
Fixes #42909.

Build/Test Tools: Remove `vendor` file name entry from `.gitignore.`

Props netweb.
Merges [42733] to the 5.0 branch.
Fixes #43411.

General: PHP 7.3 throws an `E_WARNING` when using continue to target a switch.

Applying continue to a switch is equivalent to using break and quite possibly, a continue targeting a higher level control structure is actually intended.

To target the higher level control structure, a numeric argument has to be passed to continue. This fixes two cases in WordPress Core where this is currently happening.

See: https://github.com/php/php-src/pull/3364
See: https://wiki.php.net/rfc/continue_on_switch_deprecation

Props jrf.
Merges [43653] to the 5.0 branch.
Fixes #44543.

Media: Remove checkered background for icons in Attachment Details.

Props BandonRandon.
Merges [42642] to the 5.0 branch.
Fixes #42535. See #41948.

Posts, Post Types: Add labels for post transformation messages.

Because the existing `post_updated_messages` filter can be modified dynamically based on post state, it's unreliable to use with REST API clients. Instead, these new labels give clients stateless equivalents.

Props earnjam.
Fixes #45101.

Blocks: Introduce `register_block_type()`, `unregister_block_type()`, and `get_dynamic_blocks()` functions.

These helper functions allow easy access to the global block registry.

See #45109.

Blocks: Introduce `WP_Block_Type` and `WP_Block_Type_Registry` classes.

These are the foundational classes allowing blocks to be registered and used throughout WordPress.

This commit also includes the `has_block()` and `has_blocks()` functions, which are required for unit testing these classes.

Props adamsilverstein, danielbachhuber, desrosj.
See #45097, #45109.

REST API: Fix version number in `_doing_it_wrong()` call.

`_doing_it_wrong()`, indeed.

Props joehoyle.
See #39965.

REST API: Slash existing meta values when comparing with incoming meta upates.

When comparing the old and new values for a meta key being set, ensure both values are sanitized using the same logic so that equal values match.

props boonebgorges, dcavins, MattGeri, pilou69, TimothyBlynJacobs.
Fixes #42069.

REST API: Introduce controller for searching across post types.

Introduces a `WP_REST_Search_Controller` class which registers a `/wp/v2/search` endpoint. Search types are handled by extending `WP_REST_Search_Handler`. The default search type is `WP_REST_Post_Search_Handler` but can be filtered by plugins or a theme.

Props danielbachhuber, flixos90, pento, rmccue.
Fixes #39965.

Script loader: Adjust JS packages registration.

Adjusts the packages registration after [43723]:

* Combine the different registration functions into one
`wp_default_packages` function. To reach this goal move the prefix
logic into a function so it can be called from different locations.
Use a `static` variable there to prevent duplicate inclusion of
`version.php`.
* Call this function from the `wp_default_scripts` action by
registering it as a default filter.
* Combine some of the logic in `_WP_Editors::print_tinymce_scripts`
into `wp_register_tinymce_scripts`. The logic to force an uncompressed
TinyMCE script file stays in `_WP_Editors::force_uncompressed_tinymce`
because that logic is very specific to the classic editor.
* The script handle `wp-tinymce` is now a dependency of the `editor`
script handle. In combination with the previous item, this makes the
classic editor work.
* Adjust the syntax of the script paths to be more consistent with
other WordPress code.
* Always use `"production"` mode for the media files to prevent people
from inadvertently committing development files.

Props pento, omarreiss.
Fixes #45065.

REST API: Fire actions after items are completely updated/inserted.

The existing `rest_insert_*` actions are fired before meta and additional fields are updated. These new `rest_after_*` actions fire after all write operations have completed.

Props timothyblynjacobs.
Fixes #42864.

REST API: Don't add fields to object when not included in `?_fields=`.

In [43087], we improved REST API performance by only rendering the fields specified in the request. Similarly, any fields registered with `register_rest_field()` should only be rendered when included in `?_fields=`.

Props dlh.
Fixes #45099.

REST API: Add new class file and tests missed in [43734].

See #45016.