Latest Posts block breaks when there are no intermediate image sizes

[WPprodigy]

Description

The "Latest Post" block is not usable if a site has disabled all intermediate image sizes.

To reproduce

Steps to reproduce the behavior:

1. Add add_filter( 'intermediate_image_sizes', '__return_empty_array' ); to your theme's functions.php
2. Create a new post & add the "Latest Posts" block.
3. Note the broken block: "This block has encountered an error and cannot be previewed."

What's happening

Error: An error occurred while running 'mapSelect': Cannot read property 'width' of undefined
The error may be correlated with this previous error:
TypeError: Cannot read property 'width' of undefined
    at https://vip.test/wp-includes/js/dist/block-library.min.js?ver=f710d3cc99e7a55a0d6a5418f3cfe33c:9:209846

The noted error happens here:

gutenberg/packages/block-library/src/latest-posts/edit.js

Line 478 in 59324b9

defaultImageWidth: imageDimensions[ featuredImageSizeSlug ].width,

Can replicate pretty easily with just this in the console:

const { getSettings } = wp.data.select( 'core/block-editor' );
const { imageSizes, imageDimensions } = getSettings();

// Is empty
imageDimensions

---

Editor version

• WordPress version: 5.4
• Core WP version of GB, not the extra plugin.

[Chrico]

I want to extend this issue with some more information.

---

imageDimensions
The imageDimensions are set via localized script data here:

gutenberg/lib/compat.php

Line 67 in 2a5146f

if ( ! isset( $settings['imageDimensions'] ) && ! empty( $settings['imageSizes'] ) ) {

--> Which means: They can actually be empty / contain no value at all.

---

defaults
The SETTINGS_DEFAULTS are not containing imageDimensions as well https://github.com/WordPress/gutenberg/blob/2a5146f6a078ae4ebfb9b0b806daac17674e7a95/packages/block-editor/src/store/defaults.js

--> No fallback forimageDimensions in JavaScript.

---

For me it looks like a Bug in Gutenberg itself to rely on data which is not ensured via a default in JavaScript and is not localized when set.

The latest-posts-Block should be updated in a way, which does only use images when at least 1 imageDimension is set. Otherwhise the "image"-option shouldn't be visible at all.

[WPprodigy]

Oh, I missed #21070. This can be closed!