WordPress 5.4 Compatibility

[jeherve]

For reference, here is a list of the things we should work on to ensure full compatibility with the upcoming version of WordPress.

Items checked are not impacting us, or already handled.

• Deprecating WP_Customize_New_Menu_Control, WP_Customize_New_Menu_Section, and wp.customize.Menus.NewMenuControl (reference).
• Enhancements to favicon handling (reference).
• Better information about errors in wp_login_failed (reference) SSO: Pass error value to wp_login_failed #14821
• Gutenberg -- legacy “editor-” classes (reference) Gutenberg 7.2.0: replace legacy editor- classes with block-editor- #14446
• Div with class edit-post-layout__content removed (reference)
• Meta attribute sources deprecated (reference)
• Deprecation of wordpress/nux (reference)
• Blocks: Add support for Collections Blocks: Add support for Collections #14454

Block Editor layout changes:

• Short link: buttons are off in Gutenberg 7.7 #14982
• Contact form block: guide & warning colors are grey in Gutenberg 7.7 #14975
• Open table block: empty space on right #14976
• Premium block: "paid" word is off in the inserter #14977
• Markdown block: buttons lost visual CSS with Gutenberg 7.7 #14978 (fix in Markdown Block: ensure the editor buttons look good everywhere #15315)
• Mailchimp block: no space in the setup screen #14979

Noting that the scheduled release date is planned for 31 March 2020, before Jetpack 8.4 is supposed to go out. If blockers are announced in the next few weeks, we may need to organize a point release.

[simison]

Related #14668

[nielslange]

Related #14674