This update should coincide with the last beta release (5). As usual, plenty of fixes were addressed across the different areas. Some long-standing usability issues were improved around image uploads, permalinks, columns, video backgrounds, etc. It’s now also possible for plugins to remove core panels from the Document sidebar. 

Help reviewing open PRs heading into RC will be greatly appreciated!

4.4 / WordPress 5.0 (Beta 5) 🐚

• Improves discoverability of permalinks by adding permalink panel to the document sidebar.
• Improves margins, column child block, and mobile display of columns.
• Allow for programmatically removing editor document panels.
• Replaces the uploading indicator of images and galleries with a spinner and faded out image.
• Toolbar for floats was a little offset beyond the mobile breakpoint, now fixed.
• Text and code editing blocks did not have width set, now set to fill the space.
• Correctly align URL input autocomplete.
• Improve animations: new, consistent naming convention, adds editor prefix, and moves keyframe animations (which don’t work well with mixins) into the edit post style.
• Hover styles were showing on mobile, where hover is not available – now disabled.
• Click and drag was incorrectly triggering a selection event in the block list under the popover, resulting in the popover dismissing. This was causing blocks to be selected when trying to set links to open in a new tab, for example. Fixed by preventing the mouse down event from propagating.
• Adds some padding to the block inserter so that it never overlaps text in nested contexts or mobile views.
• Better handle images larger than the editor by allowing a 2.5x buffer. Allows images inserted in TwentyNineteen and other themes that have a wider than 580px editor width, to look as expected, but prevents infinite resizing of images.
• Stop mousedown event propagating through the toolbar, fixing problem of unexpectedly selecting blocks.
• Improve the way that long words are broken on multiple lines, using word-break: keep-all;
• Preserve the ratio of video backgrounds in cover blocks, videos may be cropped to fit but will keep their original ratio.
• It was not possible to scroll a long menu on first load of Gutenberg, fixed by removing sticky-menu.

Bug Fixes

• Properly check for allowed types of Media in Media Placeholder components.
• “Resolve” and “Convert to HTML” buttons were not clickable (regression), now resolved.
• Exclude HTML editing from Columns and Column blocks.
• Better handle links without href, which were showing as `undefined`.
• Renders block appender after the template is processed, to prevent incorrectly inserting new paragraphs.
• Parent pages were being lost when draft pages were autosaved, fixed by removing parent pages from autosave requests and refactoring to stop using “parent” as the path argument name.
• Adding line breaks in formatted content in quote blocks were not working correctly, fixed by persisting formats when new lines are added.
• Prevent users in the contributor role from using blocks that require upload privileges.
• Fix block selection in removing blocks, correct typo in comparison.
• Japanese text (double byte characters) was not usable in the list block, fixed by changing handling of composition events.
• Better handles different text encodings (e.g. emoji) within a block in block validation.
• Use a query argument instead of data to prevent error being thrown on post refresh.

Accessibility

• Keyboard navigation was not working as expected in Firefox, added extra key binding.
• Adds missing alt values to images when editing.
• Better communicate block nesting level by using unordered lists.
• Fix sidebar icons being incorrectly announced in NVDA by adding a span with aria-hidden="true".
• Fixes block toolbar aria label to announce “block tools toolbar” rather than “block toolbar (a11y).
• Adjusts focus on media and text blocks to select the overall block, not the child paragraph block.

Performance

• Refactors i18n module to replaces Jed with Tannin for significant performance improvements.
• Replace getSelectedBlock and getMultiSelectedBlocks with more performant getSelectedBlockClientId and a getBlocks selectors in copy handler.
• Replace getBlock selector in favor of the more performant getBlockName.
• Replace getSelectedBlock with more performant getSelectedBlockClientId and new isBlockValid selectors in the BlockToolbar.
• Replace getSelectedBlock with more performant getSelectedBlockClientId and new isBlockValid selectors in the Block Inspector.
• Replaces getInserterItems with a new hasInserterItems selector which is more performant, and makes some adjustments to memorization.
• Avoid using the getSelectedBlock selector in autocompleters.
• Remove use of getBlock selector in the DefaultBlockAppender and EditorKeyboardShortcuts components.

Other Changes

• Move undo handling out of TinyMCE and into the RichText component.
• is_gutenberg_page incorrectly assumes get_current_screen exists, add check.
• Brings code inline with CSS standards by switching font weight to numeric values.
• Wrapped component would not the most up-to-date store values if it incurred a store state change during its own mount (e.g. dispatching during its own constructor), resolved by rerunning selection.
• Display an error message if Javascript is disabled.
• Update to React 16.6.3.
• Adds missing components dependency for RichText.
• Refactors list block to remove previously exposed RichText/TinyMCE logic.
• Removes focusOnMount prop from NavigableToolbar components, which was generating a warning.
• Refactor checks for upload permissions, removing unnecessary checks for store permissions.
• Use the large image size when inserting images in both galleries and image blocks.
• Fixes dependency of wp-polyfill which needs to be registered before React and React-Dom when plugins rely on WP’s React.
• Mark onSplit as unstable as it is pending refactor.
• Remove 4.4 deprecated features.
• Fix SCSS syntax error.
• Remove export of previously removed function.

Testing

• Add an E2E test for unsupported blocks.
• Refactor E2E utility functions.

Documentation

• Formatting updates to copy guidelines.
• Makes headings consistent in the dropdown documentation.
• Removes outdated documentation referring to function support in registerBlockType.
• Fixes some typos and line breaks in block design documentation.
• Fixes some typos and improves readability of README.

Mobile Apps

• Adds toolbar to the editing block, and edit button.
• Passes the `isSelected` prop down to the implementation of RichText components to make them respond properly to focus changes.

Deprecations removed with this version.

• Current PRs for review: 40 in 4.5 Milestone (-41 from 4.4).
• Open issues in 5.0 RC: 108 (-30) — This will be heavily triaged tomorrow based on what gets merged from current 4.5 open PRs.
• Open issues in 5.0.0: 10 (+2)
• Open issues in 5.0.1: 4
• Open issues in 5.0.x (fast follow): 37 (+15)
• Current beta: Beta 4, 12th November.
• Current plugin: 4.4, released today.
• Next Beta: Beta 5, to be released today.
• Next release: 5.0 RC, planned for next Monday.