Classic block not working

[youknowriad]

Description

At the moment, the classic block seems unusable. I can insert it but I can't type within it.
This is kind of a critical bug (especially if it impacts 7.0 which I didn't confirm)

Step-by-step reproduction instructions

1- Open the post editor
2- Insert the classic block
3- Try typing in it.

Screenshots, screen recording, code snippet

No response

Environment info

No response

Please confirm that you have searched existing issues in the repo.

• Yes

Please confirm that you have tested with all plugins deactivated except Gutenberg.

• Yes

Please confirm which theme type you used for testing.

• Block
• Classic
• Hybrid (e.g. classic with theme.json)
• Not sure

[youknowriad]

We should ensure this is validated by e2e tests once we figure out the fix.

[t-hamano]

After investigation, it appears that this issue has been present for some time and is likely related to client-side media processing. Disabling client-side media processing eliminates this issue.

add_filter( 'wp_client_side_media_processing_enabled', '__return_false' );

cc @adamsilverstein

[t-hamano]

There are E2E tests for the classic theme, but client-side media processing appears to be disabled.

gutenberg/test/e2e/specs/editor/blocks/classic.spec.js

Lines 21 to 27 in e9abf86

	test.beforeAll( async ( { requestUtils } ) => {
	// Cross-origin isolation (COEP) prevents TinyMCE from
	// initializing properly in its iframe.
	await requestUtils.activatePlugin(
	'gutenberg-test-plugin-disable-client-side-media-processing'
	);
	} );

cc @ellatrix @Mamaduka

[Mamaduka]

I thought these were removed in the follow-up. The test shouldn't run with a special case for client-side media processing, as it makes it easier to miss similar bugs.

[adamsilverstein]

@youknowriad can you check if WordPress/wordpress-develop#11098 or #75991 fixes the issue?

[adamsilverstein]

@youknowriad - I can confirm this is fixed by #75991

[adamsilverstein]

I thought these were removed in the follow-up. The test shouldn't run with a special case for client-side media processing, as it makes it easier to miss similar bugs.

Good point. We should be able to remove this once #75991 lands.

[Mamaduka]

Fixed via #75991.